0001084991-23-000120 | 10-Q | XBRL Viewer | Natural GAS Services Group INC

Stock-Based and Other Long-Term Incentive Compensation (Tables)

9 Months Ended

Sep. 30, 2023

Share-Based Payment Arrangement [Abstract]

A summary of all option activity as of December 31, 2022, and changes during the nine months ended September 30, 2023 is presented below:


	Number of Stock Options	Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (years)	Aggregate Intrinsic Value (in thousands)
Outstanding, December 31, 2022	201,584	$	19.32	3.90	$	41
Granted	1,000	$	10.12	9.76	$	—

Cancelled / Forfeited	(12,500)	$	15.60	—	4
Expired	(38,000)	$	16.28	—	—
Outstanding, September 30, 2023	152,084	$	20.33	3.81	—
Exercisable, September 30, 2023	119,750	$	22.89	2.58	$	—

Schedule of Stock Options Outstanding

The following table summarizes information about our stock options outstanding at September 30, 2023:


Range of Exercise Prices	Options Outstanding				Options Exercisable
	Shares	Weighted Average Remaining Contractual Life (years)	Weighted Average Exercise Price		Shares	Weighted Average Exercise Price
$0.01-18.00	73,000	6.22	$	12.97	40,666	$	14.65

$22.01-26.00	28,667	1.54	$	22.90	28,667	$	22.90
$26.01-30.00	19,750	3.38	$	28.15	19,750	$	28.15
$30.01-34.00	30,667	0.47	$	30.41	30,667	$	30.41
	152,084	3.81	$	20.33	119,750	$	22.89

Schedule of Status of Unvested Stock Options

The summary of the status of our unvested stock options as of December 31, 2022 and changes during the nine months ended September 30, 2023 is presented below:



Unvested Stock Options:	Shares	Weighted Average Grant Date Fair Value Per Share
Unvested at December 31, 2022	39,000	$	5.44
Granted	1,000	$	5.30
Vested, outstanding shares	(3,332)	$	6.26

Cancelled/Forfeited	(4,334)	$	5.15
Unvested at September 30, 2023	32,334	$	5.38

Schedule of Restricted Stock Activity

A summary of all restricted stock/units outstanding as of December 31, 2022 and activity during the nine months ended September 30, 2023 is presented below:


	Number of Shares	Weighted Average Grant Date Fair Value		Weighted Average Remaining Contractual Life (years)	Aggregate Intrinsic Value (in thousands)
Outstanding, December 31, 2022	250,847	$	8.40	1.42	$	2,681
Granted	153,656	$	10.41		$	1,599
Vested	(267,232)	$	9.22		$	2,683
Canceled/Forfeited	(14,357)	$	10.04		$	158
Outstanding, September 30, 2023	122,914	$	10.29	4.84	$	1,482

Earnings (loss) per Share

9 Months Ended

Sep. 30, 2023

Earnings Per Share [Abstract]

Earnings (loss) per Share

Earnings (loss) per ShareThe following table reconciles the numerators and denominators of the basic and diluted earnings per share computation:


	Three months ended				Nine months ended
	September 30,				September 30,
	2023		2022		2023		2022
	(in thousands, except per share data)
Numerator:
Net income (loss)	$	2,171	$	(80)	$	3,045	$	187
Denominator for earnings per basic common share:
Weighted average common shares outstanding	12,378		12,192		12,295		12,344
Denominator for earnings per diluted common share:
Weighted average common shares outstanding	12,378		12,192		12,295		12,344
Dilutive effect of stock options and restricted stock/units	25		—		77		90
Diluted weighted average shares	12,403		12,192		12,372		12,434
Earnings (loss) per common share:
Basic	$	0.18	$	(0.01)	$	0.25	$	0.02
Diluted	$	0.18	$	(0.01)	$	0.25	$	0.02

Stock-Based and Other Long-Term Incentive Compensation - Restricted Stock, Narrative (Details) $ in Millions						9 Months Ended
	Jun. 30, 2023 shares	May 09, 2023 independent_director shares	Apr. 25, 2023 shares	Aug. 15, 2022 executive_officer shares	Apr. 26, 2022 independent_director shares	Sep. 30, 2023 USD ($) shares	Sep. 30, 2022 USD ($)
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)						153,656
Canceled/Forfeited (in shares)						14,357
Share-based compensation expense \| $						$ 1.7	$ 1.0
Restricted Stock \| Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)					4,212
Number of independent directors \| independent_director					3
Award vesting period					1 year
Restricted Stock \| Executive Officers
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)				32,040
Award vesting period				3 years
Number of executive officers \| executive_officer				2
Canceled/Forfeited (in shares)			11,024
Restricted Stock \| Chief Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)			58,790	60,839
Restricted Stock \| Chief Technical Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)			27,840
Award vesting period			3 years
Restricted Stock Units (RSUs) \| Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)		9,470
Number of independent directors \| independent_director		4
Award vesting period		1 year
Restricted Stock Units (RSUs) \| Chief Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	10,101
Award vesting period	1 year

Stock-Based and Other Long-Term Incentive Compensation

9 Months Ended

Sep. 30, 2023

Share-Based Payment Arrangement [Abstract]

Stock-Based and Other Long-Term Incentive Compensation

Stock Options

A summary of all option activity as of December 31, 2022, and changes during the nine months ended September 30, 2023 is presented below:


	Number of Stock Options	Weighted Average Exercise Price		Weighted Average Remaining Contractual Life (years)	Aggregate Intrinsic Value (in thousands)
Outstanding, December 31, 2022	201,584	$	19.32	3.90	$	41
Granted	1,000	$	10.12	9.76	$	—

Cancelled / Forfeited	(12,500)	$	15.60	—	4
Expired	(38,000)	$	16.28	—	—
Outstanding, September 30, 2023	152,084	$	20.33	3.81	—
Exercisable, September 30, 2023	119,750	$	22.89	2.58	$	—

The following table summarizes information about our stock options outstanding at September 30, 2023:


Range of Exercise Prices	Options Outstanding				Options Exercisable
	Shares	Weighted Average Remaining Contractual Life (years)	Weighted Average Exercise Price		Shares	Weighted Average Exercise Price
$0.01-18.00	73,000	6.22	$	12.97	40,666	$	14.65

$22.01-26.00	28,667	1.54	$	22.90	28,667	$	22.90
$26.01-30.00	19,750	3.38	$	28.15	19,750	$	28.15
$30.01-34.00	30,667	0.47	$	30.41	30,667	$	30.41
	152,084	3.81	$	20.33	119,750	$	22.89

The summary of the status of our unvested stock options as of December 31, 2022 and changes during the nine months ended September 30, 2023 is presented below:



Unvested Stock Options:	Shares	Weighted Average Grant Date Fair Value Per Share
Unvested at December 31, 2022	39,000	$	5.44
Granted	1,000	$	5.30
Vested, outstanding shares	(3,332)	$	6.26

Cancelled/Forfeited	(4,334)	$	5.15
Unvested at September 30, 2023	32,334	$	5.38

As of September 30, 2023, there was $108,000 of unrecognized compensation cost related to unvested options. For the nine months ended September 30, 2023, there was $74,000 of compensation expense for stock options. For the nine months ended September 30, 2022, there was 361,000 of compensation expense for stock options.

Restricted Shares/Units

On April 26, 2022, 4,212 shares of restricted common stock were awarded to each of our three independent Board members. The restricted stock issued to these directors vests in one year from the date of grant. On August 15, 2022, the Compensation Committee awarded 32,040 shares of restricted common stock to two executive officers that vest ratably over three years, beginning on April 25, 2023 of these 32,040 shares, 11,024 shares were forfeited in connection with the executive officer's resignation. In addition, on August 15, 2022, the Compensation Committee awarded 60,839 shares of restricted stock to Stephen C. Taylor, our Interim Chief Executive Officer, that vested in full on June 30, 2023. On April 25, 2023, the Compensation Committee awarded 27,840 shares of restricted stock to our Chief Technical Officer that vest ratably over three years, beginning on April 25, 2024. Pursuant to the Retirement Agreement dated May 17, 2022, between the Company and Mr. Taylor, our Interim Chief Executive Officer, on April 25, 2023, the Compensation Committee awarded 58,790 fully vested shares of common stock to Mr. Taylor. On May 9, 2023, the Compensation Committee awarded each of our four independent Board members 9,470 restricted stock units. These restricted stock units vest one year from the date of grant. On June 30, 2023 Stephen C. Taylor was granted restricted stock units for 10,101 shares of common stock that will vest one year from the date of grant.

Total compensation expense related to these and previously granted restricted stock awards was $1.7 million and $1.0 million for the nine months ended September 30, 2023, and 2022, respectively.

A summary of all restricted stock/units outstanding as of December 31, 2022 and activity during the nine months ended September 30, 2023 is presented below:


	Number of Shares	Weighted Average Grant Date Fair Value		Weighted Average Remaining Contractual Life (years)	Aggregate Intrinsic Value (in thousands)
Outstanding, December 31, 2022	250,847	$	8.40	1.42	$	2,681
Granted	153,656	$	10.41		$	1,599
Vested	(267,232)	$	9.22		$	2,683
Canceled/Forfeited	(14,357)	$	10.04		$	158
Outstanding, September 30, 2023	122,914	$	10.29	4.84	$	1,482

Other Long-Term Incentive Compensation

On April 26, 2022, subject to vesting we granted a $50,000 cash award to each of our three independent Board members. These awards vested on April 26, 2023 and have been paid. The Company accounts for these other long-term incentive awards as liabilities under accrued liabilities on our condensed consolidated balance sheet. In general the vesting of long term awards is subject to acceleration upon certain events, such as (i) death or disability of the recipient, (ii) certain circumstances in connection with a change of control of the Company, (iii) for executive officers, termination without cause (as defined in the agreement), and (iv) for executive officers, resignation for good reason (as defined in the agreement). Total compensation expense related to these and other long-term incentive awards was approximately $426,000 and $672,000 for the nine months ended September 30, 2023 and 2022, respectively. As of September 30, 2023, all compensation expense related to these other long-term incentive awards had been recognized.

Description of Business	9 Months Ended
Description of Business	Sep. 30, 2023
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business	Description of BusinessNatural Gas Services Group, Inc. (the "Company", “NGS”, "Natural Gas Services Group", "we" or "our") (a Colorado corporation), is a leading provider of natural gas compression equipment, technology and services to the energy industry. The Company manufactures, fabricates, rents, sells and maintains natural gas compressors systems for oil and natural gas production and plant facilities. NGS is headquartered in Midland, Texas, with fabrication facilities located in Tulsa, Oklahoma and Midland, Texas, and service facilities located in major oil and natural gas producing basins in the U.S. The company also has increasingly used third-party fabricators as well.

Summary of Significant Accounting Policies (Policies)	9 Months Ended
Summary of Significant Accounting Policies (Policies)	Sep. 30, 2023
Accounting Policies [Abstract]
Principles of Consolidation and Basis of Presentation	Principles of Consolidation and Basis of Presentation The accompanying unaudited condensed consolidated financial statements include the accounts of the Company, its subsidiary, NGSG Properties, LLC and the rabbi trust associated with the Company's deferred compensation plan. All significant intercompany accounts and transactions for the periods presented have been eliminated in consolidation. These financial statements include all adjustments, consisting of only normal recurring adjustments, which are necessary to make our financial position at September 30, 2023 and the results of our operations for the three and nine months ended September 30, 2023 and 2022 not misleading. Some adjustments may cause the prior year number in these financial statements to differ from the prior year interim financial statements. As permitted by the rules and regulations of the Securities and Exchange Commission (the "SEC"), the accompanying condensed consolidated financial statements do not include all disclosures normally required by generally accepted accounting principles in the United States of America (GAAP). These financial statements should be read in conjunction with the consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2022 on file with the SEC. In our opinion, the condensed consolidated financial statements are a fair presentation of the financial position, results of operations, changes in stockholders' equity and cash flows for the periods presented. The results of operations for the three and nine months ended September 30, 2023 are not necessarily indicative of the results of operations to be expected for the full fiscal year ending December 31, 2023.
Revenue Recognition Policy and Contract Costs	Revenue Recognition Policy The Company recognizes revenue in accordance with ASC 606, Revenue from Contracts with Customers ("ASC 606"), except for rental revenue as discussed below. Under ASC 606, revenue is measured based on a consideration specified in a customer’s contract, excluding any sale incentives and taxes collected on behalf of third parties (i.e. sales and property taxes). Revenue is recognized when a customer obtains control of promised goods or services in an amount that reflects the consideration that we expect to receive for those goods or services. To recognize revenue, we (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when, or as, we satisfy the performance obligation(s). Shipping and handling costs incurred are accounted for as fulfillment costs and are included in cost of revenues in our condensed consolidated statements of operations. Nature of Goods and Services The following is a description of principal activities from which the Company generates its revenue: Rental Revenue. The Company generates revenue from renting compressor systems to our customers. These contracts, which all qualify as operating leases under ASC Topic 842, Leases (ASC 842), may also include a fee for servicing the compressor during the rental contract period. Our rental contracts typically range from six to 24 months, with our larger horsepower compressors having contract terms of up to 60 months. Our revenue is recognized over time, generally monthly, in accordance with payment terms under the contract. After the terms of the contract have expired, a customer may renew their contract or continue renting on a monthly basis thereafter. In accordance with ASC 842, we have applied the practical expedient ASC 842-10-15-42A, which allows the Company to combine lease and non-lease components. Sales Revenue. The Company generates revenue by the sale of custom/fabricated compressors, and parts, as well as, exchange/rebuilding customer owned compressors and sale of used rental equipment. Custom/fabricated compressors - The Company designs and fabricates compressors based on the customer’s specifications outlined in their contract. Though the equipment being built is customized by the customer, control under these contracts does not pass to the customer until the compressor package is complete and shipped, or in accordance with a bill and hold arrangement, the customer accepts title and assumes the risk and rewards of ownership. We request some of our customers to make progressive payments as the product is being built; these payments are recorded as a contract liability on the Deferred Income line on the condensed consolidated balance sheet until control has been transferred. These contracts also may include an assurance warranty clause to guarantee the product is free from defects in material and workmanship for a set duration of time; this is a standard industry practice and is not considered a performance obligation. From time to time we recognize revenue when manufacturing is complete and the equipment is ready for shipment. At the customer’s request, we will bill the customer upon completing all performance obligations, but before shipment. The customer will formally request that we ship the equipment per their direction from our manufacturing facility or the third-party fabrication site at a later specified date and that we segregate this equipment from our finished goods, such that this equipment is not available to fill other orders. Per the customer’s agreement change of control is passed to the customer once the equipment is complete and ready for shipment. We have operated using bill and hold agreements with certain customers for many years, with consistent and satisfactory results for both the customer and us. The credit terms on these agreements are consistent with the credit terms on all other sales. All control is maintained by the customer and there are no exceptions to the customer’s commitment to accept and pay for the manufactured equipment. There was no revenue recognized for bill and hold arrangements for the nine months ended September 30, 2023 or 2022. Parts - Revenue is recognized after the customer obtains control of the parts. Control is passed either by the customer taking physical possession or the parts being shipped. The amount of revenue recognized is not adjusted for expected returns, as our historical part returns have been de minimis. Exchange or rebuilding customer owned compressors - Based on the contract, the Company will either exchange a new/rebuilt compressor for the customer’s malfunctioning compressor or rebuild the customer’s compressor. Revenue is recognized after control of the replacement compressor has transferred to the customer based on the terms of the contract, i.e., by physical delivery, delivery and installment, or shipment of the compressor. Used compressors - From time to time, a customer may request to purchase a used compressor out of our rental fleet. Revenue from the sale of rental equipment is recognized when the control has passed to the customer based on the terms of the contract, i.e., when the customer has taken physical possession or the equipment has been shipped. Aftermarket Services. The Company provides routine or call-out services on customer owned equipment. Revenue is recognized after services are rendered. The company also provides freight and commissioning services for new compressor sets. Payment terms for sales revenue and aftermarket services discussed above are generally 30 to 60 days, although terms for specific customers can vary. Also, transaction prices are not subject to variable consideration constraints. Contract Costs The Company recognizes the incremental costs of obtaining contracts as an expense when incurred if the amortization period of the assets that the Company otherwise would have recognized is one year or less. These costs are included in selling, general and administrative expenses on our condensed consolidated statements of operations.
Income Taxes	Income Taxes Deferred tax assets and liabilities are recognized for the future tax consequences attributable to temporary differences between the financial statement carrying amounts of assets and liabilities and their respective tax bases, and operating losses and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. Valuation allowances are established to reduce deferred tax assets when it is more likely than not that some portion or all of the deferred tax assets will not be realized. To the extent we establish a valuation allowance or increase this allowance in a period, we include an expense in the tax provision in our condensed consolidated statements of operations. We account for uncertain tax positions in accordance with guidance in ASC 740, which prescribes the minimum recognition threshold a tax position taken or expected to be taken in a tax return is required to meet before being recognized in the condensed consolidated financial statements. Tax benefits are recognized only for tax positions that are more likely than not to be sustained upon examination by tax authorities. The amount recognized is measured as the largest amount of benefit that is greater than 50% likely to be realized upon settlement. A liability for unrecognized tax benefits is recorded for any tax benefits claimed in our tax returns that do not meet these recognition and measurement standards. We have no liabilities for uncertain tax positions as of September 30, 2023. Our policy regarding income tax interest and penalties is to expense those items as interest expense and other expense, respectively.
Capitalized Interest	Capitalized Interest Effective January 1, 2023, the Company began capitalizing interest from external borrowings on significant expenditures for the fabrication of its natural gas compressor equipment until such projects are ready for their intended use. Capitalized interest is added to the cost of the underlying asset and is amortized over the useful lives of the assets in the same manner as the underlying assets.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements In June 2016, the FASB issued ASU 2016-13, Financial Instruments-Credit Losses (ASC Topic 326): Measurement of Credit Losses on Financial Instruments. The amendments to ASC Topic 326 require immediate recognition of estimated credit losses expected to occur over the remaining life of many financial assets, including trade receivables. For companies that qualify as smaller reporting companies, the amendments in this update are effective for interim and annual periods beginning after January 1, 2023. We adopted ASU 2016-13 on January 1, 2023. The adoption did not result in any material change to our financial statements. There were no other recent accounting pronouncements during the nine months ended September 30, 2023 that are expected to have a material impact on our financial statements.

- Definition

Disclosure of accounting policy for income taxes, which may include its accounting policies for recognizing and measuring deferred tax assets and liabilities and related valuation allowances, recognizing investment tax credits, operating loss carryforwards, tax credit carryforwards, and other carryforwards, methodologies for determining its effective income tax rate and the characterization of interest and penalties in the financial statements.

+ References + Details

- Definition

Disclosure of accounting policy for revenue from contract with customer.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 17
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-17

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 19
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-19

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-18

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 18
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-18

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 20
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-20

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 20
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-20

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 20
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-20

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 20
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-20

Reference 9: http://www.xbrl.org/2003/role/exampleRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (e)
-SubTopic 10
-Topic 235
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483426/235-10-50-4

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Name Accounting Standards Codification
-Topic 606
-Publisher FASB
-URI https://asc.fasb.org//606/tableOfContent

+ Details

Long-term Debt - Narrative (Details) - Revolving credit facility - Line of Credit - USD ($) $ in Millions			9 Months Ended	12 Months Ended
	Feb. 28, 2023	May 11, 2021	Sep. 30, 2023	Dec. 31, 2022
New Credit Agreement
Line of Credit Facility [Line Items]
Debt instrument, term		5 years
Borrowing base amount available		$ 20.0
Aggregate credit agreement commitment		$ 30.0
Outstanding balance				$ 25.0
Weighted average interest rate				7.32%
Amended and Restated Credit Agreement
Line of Credit Facility [Line Items]
Debt instrument, term	5 years
Borrowing base amount available	$ 175.0		$ 175.0
Outstanding balance			$ 128.0
Weighted average interest rate			8.98%
Potential increase in borrowing capacity	125.0
Potential maximum borrowing capacity	$ 300.0
Borrowing base, component, percentage of eligible accounts receivable	85.00%
Percentage of eligible inventory	50.00%
Line of credit facility, non exceeding cap of components	$ 2.5
Percentage of eligible compressors for extension of credit	95.00%
Term for depreciation	25 years
Percentage of net liquidation value of eligible compressors for extension of credit	80.00%
Percentage of eligible value at cost	80.00%
Unused commitment fee, rate	0.50%
Maximum leverage ratio allowed	3.50
Fixed charge coverage ratio	1.25
Outstanding credit facility			$ 47.0
Amended and Restated Credit Agreement \| Maximum
Line of Credit Facility [Line Items]
Default trigger, certain defaults of other company indebtedness, amount	$ 1.0
Default trigger, rendering of certain judgments, amount	$ 1.0
Amended and Restated Credit Agreement \| Federal Fund Rate
Line of Credit Facility [Line Items]
Variable rate, applicable margin	0.50%
Amended and Restated Credit Agreement \| SOFR Rate
Line of Credit Facility [Line Items]
Variable rate, applicable margin	1.00%
Amended and Restated Credit Agreement \| SOFR Rate \| Minimum
Line of Credit Facility [Line Items]
Variable rate, applicable margin	3.00%
Amended and Restated Credit Agreement \| SOFR Rate \| Maximum
Line of Credit Facility [Line Items]
Variable rate, applicable margin	3.75%
Amended and Restated Credit Agreement \| Base Rate \| Minimum
Line of Credit Facility [Line Items]
Variable rate, applicable margin	2.00%
Amended and Restated Credit Agreement \| Base Rate \| Maximum
Line of Credit Facility [Line Items]
Variable rate, applicable margin	2.75%

Rental Equipment

9 Months Ended

Sep. 30, 2023

Property, Plant and Equipment [Abstract]

Rental Equipment

Our rental equipment and associated accumulated depreciation as of September 30, 2023 and December 31, 2022, respectively, consisted of the following:


	September 30, 2023		December 31, 2022
	(in thousands)
Compressor units	$	494,282	$	387,145
Work-in-process	54,895		37,034
Rental equipment	549,177		424,179
Accumulated depreciation	(193,795)		(177,729)
Rental equipment, net of accumulated depreciation	$	355,382	$	246,450

We evaluated our rental equipment for potential material impairment as of September 30, 2023, and determined that no such impairment existed as of that date.

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
CASH FLOWS FROM OPERATING ACTIVITIES:
Net income	$ 3,045	$ 187
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	19,390	18,118
Amortization of debt issuance costs	287	35
Deferred income tax expense	1,408	285
Stock-based compensation	1,826	1,337
Bad debt allowance	199	0
Impairment expense	779	0
Gain on sale of assets	(281)	(106)
Loss (gain) on company owned life insurance	49	551
Changes in operating assets and liabilities:
Trade accounts receivables	(13,572)	(2,210)
Inventory	(2,608)	(2,576)
Prepaid expenses and prepaid income taxes	(281)	(417)
Accounts payable and accrued liabilities	14,951	6,592
Deferred income	(37)	(1,312)
Other	543	(309)
NET CASH PROVIDED BY OPERATING ACTIVITIES	25,698	20,175
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of rental equipment, property and other equipment	(128,563)	(35,250)
Purchase of company owned life insurance	(378)	(272)
Proceeds from sale of property and equipment	231	167
NET CASH USED IN INVESTING ACTIVITIES	(128,710)	(35,355)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds from loan	103,000	2,000
Payments of other long-term liabilities, net	(50)	(2)
Payments of debt issuance costs	(2,131)	0
Purchase of treasury shares	0	(6,660)
Taxes paid related to net share settlement of equity awards	(982)	(515)
NET CASH PROVIDED BY (USED IN) FINANCING ACTIVITIES	99,837	(5,177)
NET CHANGE IN CASH AND CASH EQUIVALENTS	(3,175)	(20,357)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	3,372	22,942
CASH AND CASH EQUIVALENTS AT END OF PERIOD	197	2,585
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
Interest paid	4,347	25
NON-CASH TRANSACTIONS
Right of use asset acquired through an operating lease	63	91
Transfer of rental equipment to inventory	$ 708	$ 0

Summary of Significant Accounting Policies - Narrative (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Revenue from External Customer [Line Items]
Revenue	$ 31,369,000	$ 22,043,000	$ 84,946,000	$ 62,304,000
Deferred income	0		0		$ 37,000
Uncertain tax position	$ 0		0
Capitalized interest			4,100,000
Sales
Revenue from External Customer [Line Items]
Revenue recognized			37,000
Bill and Hold Arrangement
Revenue from External Customer [Line Items]
Revenue			$ 0	$ 0
Minimum
Revenue from External Customer [Line Items]
Amortization period of capitalized contract costs	1 year		1 year
Rental Contracts, Excluding Large Horsepower Compressors \| Minimum
Revenue from External Customer [Line Items]
Rental contract term	6 months		6 months
Rental Contracts, Excluding Large Horsepower Compressors \| Maximum
Revenue from External Customer [Line Items]
Rental contract term	24 months		24 months
Rental Contracts, Large Horsepower Compressors \| Maximum
Revenue from External Customer [Line Items]
Rental contract term	60 months		60 months

Summary of Significant Accounting Policies

9 Months Ended

Sep. 30, 2023

Accounting Policies [Abstract]

Summary of Significant Accounting Policies

Principles of Consolidation and Basis of Presentation

The accompanying unaudited condensed consolidated financial statements include the accounts of the Company, its subsidiary, NGSG Properties, LLC and the rabbi trust associated with the Company's deferred compensation plan. All significant intercompany accounts and transactions for the periods presented have been eliminated in consolidation.

These financial statements include all adjustments, consisting of only normal recurring adjustments, which are necessary to make our financial position at September 30, 2023 and the results of our operations for the three and nine months ended September 30, 2023 and 2022 not misleading. Some adjustments may cause the prior year number in these financial statements to differ from the prior year interim financial statements. As permitted by the rules and regulations of the Securities and Exchange Commission (the "SEC"), the accompanying condensed consolidated financial statements do not include all disclosures normally required by generally accepted accounting principles in the United States of America (GAAP). These financial statements should be read in conjunction with the consolidated financial statements included in our Annual Report on Form 10-K for the year ended December 31, 2022 on file with the SEC. In our opinion, the condensed consolidated financial statements are a fair presentation of the financial position, results of operations, changes in stockholders' equity and cash flows for the periods presented.

The results of operations for the three and nine months ended September 30, 2023 are not necessarily indicative of the results of operations to be expected for the full fiscal year ending December 31, 2023.

Revenue Recognition Policy

The Company recognizes revenue in accordance with ASC 606, Revenue from Contracts with Customers ("ASC 606"), except for rental revenue as discussed below. Under ASC 606, revenue is measured based on a consideration specified in a customer’s contract, excluding any sale incentives and taxes collected on behalf of third parties (i.e. sales and property taxes). Revenue is recognized when a customer obtains control of promised goods or services in an amount that reflects the consideration that we expect to receive for those goods or services. To recognize revenue, we (i) identify the contract(s) with a customer; (ii) identify the performance obligations in the contract; (iii) determine the transaction price; (iv) allocate the transaction price to the performance obligations in the contract; and (v) recognize revenue when, or as, we satisfy the performance obligation(s). Shipping and handling costs incurred are accounted for as fulfillment costs and are included in cost of revenues in our condensed consolidated statements of operations.

Nature of Goods and Services

The following is a description of principal activities from which the Company generates its revenue:

Rental Revenue. The Company generates revenue from renting compressor systems to our customers. These contracts, which all qualify as operating leases under ASC Topic 842, Leases (ASC 842), may also include a fee for servicing the compressor during the rental contract period. Our rental contracts typically range from six to 24 months, with our larger horsepower compressors having contract terms of up to 60 months. Our revenue is recognized over time, generally monthly, in accordance with payment terms under the contract. After the terms of the contract have expired, a customer may renew their contract or continue renting on a monthly basis thereafter. In accordance with ASC 842, we have applied the practical expedient ASC 842-10-15-42A, which allows the Company to combine lease and non-lease components.

Sales Revenue. The Company generates revenue by the sale of custom/fabricated compressors, and parts, as well as, exchange/rebuilding customer owned compressors and sale of used rental equipment.

Custom/fabricated compressors - The Company designs and fabricates compressors based on the customer’s specifications outlined in their contract. Though the equipment being built is customized by the customer, control under these contracts does not pass to the customer until the compressor package is complete and shipped, or in accordance with a bill and hold arrangement, the customer accepts title and assumes the risk and rewards of ownership. We request some of our customers to make progressive payments as the product is being built; these payments are recorded as a contract liability on the Deferred Income line on the condensed consolidated balance sheet until control has been transferred. These contracts also may include an assurance warranty clause to guarantee the product is free from defects in material and workmanship for a set duration of time; this is a standard industry practice and is not considered a performance obligation.

From time to time we recognize revenue when manufacturing is complete and the equipment is ready for shipment. At the customer’s request, we will bill the customer upon completing all performance obligations, but before shipment. The customer will formally request that we ship the equipment per their direction from our manufacturing facility or the third-party fabrication site at a later specified date and that we segregate this equipment from our finished goods, such that this equipment is not available to fill other orders. Per the customer’s agreement change of control is passed to the customer once the equipment is complete and ready for shipment. We have operated using bill and hold agreements with certain customers for many years, with consistent and satisfactory results for both the customer and us. The credit terms on these agreements are consistent with the credit terms on all other sales. All control is maintained by the customer and there are no exceptions to the customer’s commitment to accept and pay for the manufactured equipment. There was no revenue recognized for bill and hold arrangements for the nine months ended September 30, 2023 or 2022.

Parts - Revenue is recognized after the customer obtains control of the parts. Control is passed either by the customer taking physical possession or the parts being shipped. The amount of revenue recognized is not adjusted for expected returns, as our historical part returns have been de minimis.

Exchange or rebuilding customer owned compressors - Based on the contract, the Company will either exchange a new/rebuilt compressor for the customer’s malfunctioning compressor or rebuild the customer’s compressor. Revenue is recognized after control of the replacement compressor has transferred to the customer based on the terms of the contract, i.e., by physical delivery, delivery and installment, or shipment of the compressor.

Used compressors - From time to time, a customer may request to purchase a used compressor out of our rental fleet. Revenue from the sale of rental equipment is recognized when the control has passed to the customer based on the terms of the contract, i.e., when the customer has taken physical possession or the equipment has been shipped.

Aftermarket Services. The Company provides routine or call-out services on customer owned equipment. Revenue is recognized after services are rendered. The company also provides freight and commissioning services for new compressor sets.

Payment terms for sales revenue and aftermarket services discussed above are generally 30 to 60 days, although terms for specific customers can vary. Also, transaction prices are not subject to variable consideration constraints.

Disaggregation of Revenue

The following table shows the Company's revenue disaggregated by product or service type for the three and nine months ended September 30, 2023 and 2022:


	Three months ended September 30,				Nine months ended September 30,
	2023		2022		2023		2022
	(in thousands)				(in thousands)
Compressors - sales	$	207	$	1,300	$	1,214	$	3,553
Flares - sales	—		131		87		214
Other (parts/rebuilds) - sales	1,206		1,655		4,699		3,503
Aftermarket services	2,251		326		4,413		1,129
Total revenue from contracts with customers	3,664		3,412		10,413		8,399
Add: ASC 842 rental revenue	27,705		18,631		74,533		53,905
Total revenue	$	31,369	$	22,043	$	84,946	$	62,304

Contract Balances

As of September 30, 2023 and December 31, 2022, we had the following receivables and deferred income from contracts with customers:


	September 30, 2023		December 31, 2022
	(in thousands)
Accounts Receivable
Accounts receivable - contracts with customers	$	5,207	$	4,353
Accounts receivable - ASC 842	23,363		10,653
Total Accounts Receivable	28,570		15,006
Less: Allowance for doubtful accounts	(529)		(338)
Total Accounts Receivable, net	$	28,041	$	14,668

Deferred income	$	—	$	37

The Company recognized sales revenues of $37 thousand for the nine months ended September 30, 2023 that was included in deferred income at the beginning of 2023.

The increase in accounts receivable and decrease in deferred income were primarily due to normal timing differences between our performance and the customers’ payments.

Remaining Performance Obligations

As of September 30, 2023, the Company had no deferred revenue related to unsatisfied performance obligations.

Contract Costs

The Company recognizes the incremental costs of obtaining contracts as an expense when incurred if the amortization period of the assets that the Company otherwise would have recognized is one year or less. These costs are included in selling, general and administrative expenses on our condensed consolidated statements of operations.

Income Taxes

Deferred tax assets and liabilities are recognized for the future tax consequences attributable to temporary differences between the financial statement carrying amounts of assets and liabilities and their respective tax bases, and operating losses and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. Valuation allowances are established to reduce deferred tax assets when it is more likely than not that some portion or all of the deferred tax assets will not be realized. To the extent we establish a valuation allowance or increase this allowance in a period, we include an expense in the tax provision in our condensed consolidated statements of operations.

We account for uncertain tax positions in accordance with guidance in ASC 740, which prescribes the minimum recognition threshold a tax position taken or expected to be taken in a tax return is required to meet before being recognized in the condensed consolidated financial statements. Tax benefits are recognized only for tax positions that are more likely than not to be sustained upon examination by tax authorities. The amount recognized is measured as the largest amount of benefit that is greater than 50% likely to be realized upon settlement. A liability for unrecognized tax benefits is recorded for any tax benefits claimed in our tax returns that do not meet these recognition and measurement standards. We have no liabilities for uncertain tax positions as of September 30, 2023.

Our policy regarding income tax interest and penalties is to expense those items as interest expense and other expense, respectively.

Capitalized Interest

Effective January 1, 2023, the Company began capitalizing interest from external borrowings on significant expenditures for the fabrication of its natural gas compressor equipment until such projects are ready for their intended use. Capitalized interest is added to the cost of the underlying asset and is amortized over the useful lives of the assets in the same manner as the underlying assets. For the nine months ended September 30, 2023, the Company capitalized interest aggregating approximately $4.1 million.

Recently Issued Accounting Pronouncements

In June 2016, the FASB issued ASU 2016-13, Financial Instruments-Credit Losses (ASC Topic 326): Measurement of Credit Losses on Financial Instruments. The amendments to ASC Topic 326 require immediate recognition of estimated credit losses expected to occur over the remaining life of many financial assets, including trade receivables. For companies that qualify as smaller reporting companies, the amendments in this update are effective for interim and annual periods beginning after January 1, 2023. We adopted ASU 2016-13 on January 1, 2023. The adoption did not result in any material change to our financial statements. There were no other recent accounting pronouncements during the nine months ended September 30, 2023 that are expected to have a material impact on our financial statements.

Stock-Based and Other Long-Term Incentive Compensation - Stock Option, Narrative (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation expense	$ 108
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 74	$ 361

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 35
-Paragraph 1D
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480483/718-10-35-1D

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 35
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480483/718-10-35-3

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)(3)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(ii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(01)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(02)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(03)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(04)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(ii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(01)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(02)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)(2)(iii)(03)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (d)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (e)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (e)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 24: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 25: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(ii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 26: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(iii)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 27: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(iv)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

Reference 28: http://www.xbrl.org/2003/role/disclosureRef
-Topic 718
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(v)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480429/718-10-50-2

+ Details

Earnings (loss) per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022
Numerator:
Net income (loss)	$ 2,171	$ 504	$ 370	$ (80)	$ (70)	$ 337	$ 3,045	$ 187
Denominator for earnings per basic common share:
Weighted average common shares outstanding (in shares)	12,378			12,192			12,295	12,344
Denominator for earnings per diluted common share:
Weighted average common shares outstanding (in shares)	12,378			12,192			12,295	12,344
Dilutive effect of stock options and restricted stock/units (in shares)	25			0			77	90
Diluted weighted average shares (in shares)	12,403			12,192			12,372	12,434
Earnings (loss) per common share:
Basic (in dollars per share)	$ 0.18			$ (0.01)			$ 0.25	$ 0.02
Diluted (in dollars per share)	$ 0.18			$ (0.01)			$ 0.25	$ 0.02

Subsequent Events	9 Months Ended
Subsequent Events	Sep. 30, 2023
Subsequent Events [Abstract]
Subsequent Events	Subsequent EventsIn accordance with ASC 855 - Subsequent Events - the Company has evaluated all events subsequent to the balance sheet date as of September 30, 2023 through the date this report was issued and believes nothing is required thereunder.

Inventory - Schedule of Inventory Allowance (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Inventory Valuation Reserves [Roll Forward]
Beginning balance	$ 120	$ 64
Accruals	0	83
Write-offs	(80)	(27)
Ending balance	$ 40	$ 120

Condensed Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Total	Preferred Stock	Common Stock	Additional Paid-In Capital	Retained Earnings	Treasury Stock
Beginning balance (in shares) at Dec. 31, 2021		0
Beginning balance at Dec. 31, 2021	$ 235,910	$ 0	$ 134	$ 114,017	$ 130,103	$ (8,344)
Beginning balance (in shares) at Dec. 31, 2021			13,394
Beginning balance (in shares) at Dec. 31, 2021						775
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Compensation expense on common stock options	21			21
Issuance of restricted stock (in shares)			79
Compensation expense on restricted common stock	402		$ 1	401
Taxes paid related to net shares settlement of equity awards	(359)			(359)
Purchase of treasury shares (in shares)						247
Purchase of treasury shares	(2,928)					$ (2,928)
Net income (loss)	337				337
Ending balance (in shares) at Mar. 31, 2022		0
Ending balance at Mar. 31, 2022	233,383	$ 0	$ 135	114,080	130,440	$ (11,272)
Ending balance (in shares) at Mar. 31, 2022			13,473
Ending balance (in shares) at Mar. 31, 2022						1,022
Beginning balance (in shares) at Dec. 31, 2021		0
Beginning balance at Dec. 31, 2021	235,910	$ 0	$ 134	114,017	130,103	$ (8,344)
Beginning balance (in shares) at Dec. 31, 2021			13,394
Beginning balance (in shares) at Dec. 31, 2021						775
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	187
Ending balance (in shares) at Sep. 30, 2022		0
Ending balance at Sep. 30, 2022	230,259	$ 0	$ 135	114,838	130,290	$ (15,004)
Ending balance (in shares) at Sep. 30, 2022			13,499
Ending balance (in shares) at Sep. 30, 2022						1,310
Beginning balance (in shares) at Mar. 31, 2022		0
Beginning balance at Mar. 31, 2022	233,383	$ 0	$ 135	114,080	130,440	$ (11,272)
Beginning balance (in shares) at Mar. 31, 2022			13,473
Beginning balance (in shares) at Mar. 31, 2022						1,022
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Compensation expense on common stock options	147			147
Issuance of restricted stock (in shares)			26
Compensation expense on restricted common stock	184			184
Taxes paid related to net shares settlement of equity awards	(156)			(156)
Purchase of treasury shares (in shares)						288
Purchase of treasury shares	(3,732)					$ (3,732)
Net income (loss)	(70)				(70)
Ending balance (in shares) at Jun. 30, 2022		0
Ending balance at Jun. 30, 2022	229,756	$ 0	$ 135	114,255	130,370	$ (15,004)
Ending balance (in shares) at Jun. 30, 2022			13,499
Ending balance (in shares) at Jun. 30, 2022						1,310
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Compensation expense on common stock options	193			193
Compensation expense on restricted common stock	390			390
Net income (loss)	(80)				(80)
Ending balance (in shares) at Sep. 30, 2022		0
Ending balance at Sep. 30, 2022	$ 230,259	$ 0	$ 135	114,838	130,290	$ (15,004)
Ending balance (in shares) at Sep. 30, 2022			13,499
Ending balance (in shares) at Sep. 30, 2022						1,310
Beginning balance (in shares) at Dec. 31, 2022	0	0
Beginning balance at Dec. 31, 2022	$ 230,076	$ 0	$ 135	115,411	129,534	$ (15,004)
Beginning balance (in shares) at Dec. 31, 2022	13,519		13,519
Beginning balance (in shares) at Dec. 31, 2022	1,310					1,310
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Compensation expense on common stock options	$ 22			22
Issuance of restricted stock (in shares)			29
Compensation expense on restricted common stock	465			465
Taxes paid related to net shares settlement of equity awards	(184)			(184)
Net income (loss)	370				370
Ending balance (in shares) at Mar. 31, 2023		0
Ending balance at Mar. 31, 2023	$ 230,749	$ 0	$ 135	115,714	129,904	$ (15,004)
Ending balance (in shares) at Mar. 31, 2023			13,548
Ending balance (in shares) at Mar. 31, 2023						1,310
Beginning balance (in shares) at Dec. 31, 2022	0	0
Beginning balance at Dec. 31, 2022	$ 230,076	$ 0	$ 135	115,411	129,534	$ (15,004)
Beginning balance (in shares) at Dec. 31, 2022	13,519		13,519
Beginning balance (in shares) at Dec. 31, 2022	1,310					1,310
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ 3,045
Ending balance (in shares) at Sep. 30, 2023	0	0
Ending balance at Sep. 30, 2023	$ 233,965	$ 0	$ 136	116,254	132,579	$ (15,004)
Ending balance (in shares) at Sep. 30, 2023	13,688		13,688
Ending balance (in shares) at Sep. 30, 2023	1,310					1,310
Beginning balance (in shares) at Mar. 31, 2023		0
Beginning balance at Mar. 31, 2023	$ 230,749	$ 0	$ 135	115,714	129,904	$ (15,004)
Beginning balance (in shares) at Mar. 31, 2023			13,548
Beginning balance (in shares) at Mar. 31, 2023						1,310
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Compensation expense on common stock options	30			30
Issuance of restricted stock (in shares)			140
Issuance of restricted stock	0		$ 1	(1)
Compensation expense on restricted common stock	1,100			1,100
Taxes paid related to net shares settlement of equity awards	(798)			(798)
Net income (loss)	504				504
Ending balance (in shares) at Jun. 30, 2023		0
Ending balance at Jun. 30, 2023	231,585	$ 0	$ 136	116,045	130,408	$ (15,004)
Ending balance (in shares) at Jun. 30, 2023			13,688
Ending balance (in shares) at Jun. 30, 2023						1,310
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Compensation expense on common stock options	22			22
Compensation expense on restricted common stock	187			187
Net income (loss)	$ 2,171				2,171
Ending balance (in shares) at Sep. 30, 2023	0	0
Ending balance at Sep. 30, 2023	$ 233,965	$ 0	$ 136	$ 116,254	$ 132,579	$ (15,004)
Ending balance (in shares) at Sep. 30, 2023	13,688		13,688
Ending balance (in shares) at Sep. 30, 2023	1,310					1,310

Condensed Consolidated Balance Sheets - USD ($)	Sep. 30, 2023	Dec. 31, 2022
Current Assets:
Cash and cash equivalents	$ 197,000	$ 3,372,000
Trade accounts receivable, net of allowance for doubtful accounts of $529 and $338, respectively	28,041,000	14,668,000
Inventory	26,115,000	23,414,000
Federal income tax receivable (Note 4)	11,538,000	11,538,000
Prepaid income taxes	0	10,000
Prepaid expenses and other	1,436,000	1,145,000
Total current assets	67,327,000	54,147,000
Long-term inventory, net of allowance for obsolescence of $40 and $120, respectively	2,172,000	1,557,000
Rental equipment, net of accumulated depreciation of $193,795 and $177,729, respectively	355,382,000	246,450,000
Property and equipment, net of accumulated depreciation of $17,737 and $16,981, respectively	21,074,000	22,176,000
Right of use assets - operating leases, net of accumulated amortization $864 and $721, respectively	261,000	349,000
Intangibles, net of accumulated amortization of $2,353 and $2,259, respectively	806,000	900,000
Other assets	4,791,000	2,667,000
Total assets	451,813,000	328,246,000
Current Liabilities:
Accounts payable	30,550,000	6,481,000
Accrued liabilities	14,608,000	23,726,000
Current operating leases	98,000	155,000
Deferred income	0	37,000
Total current liabilities	45,256,000	30,399,000
Long-term debt	128,000,000	25,000,000
Deferred income tax liability	41,206,000	39,798,000
Long-term operating leases	163,000	194,000
Other long-term liabilities	3,223,000	2,779,000
Total liabilities	217,848,000	98,170,000
Commitments and contingencies (Note 9)
Stockholders’ Equity:
Preferred stock, 5,000 shares authorized, no shares issued or outstanding	0	0
Common stock, 30,000 shares authorized, par value $0.01; 13,688 and 13,519 shares issued, respectively	136,000	135,000
Additional paid-in capital	116,254,000	115,411,000
Retained earnings	132,579,000	129,534,000
Treasury shares, at cost, 1,310 shares	(15,004,000)	(15,004,000)
Total stockholders' equity	233,965,000	230,076,000
Total liabilities and stockholders' equity	$ 451,813,000	$ 328,246,000

Stock-Based and Other Long-Term Incentive Compensation - Stock Options Outstanding (Details)	9 Months Ended
	Sep. 30, 2023 $ / shares shares
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options outstanding, shares (in shares) \| shares	152,084
Options outstanding, weighted average remaining contractual life (years)	3 years 9 months 21 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 20.33
Options exercisable, shares (in shares) \| shares	119,750
Options exercisable, weighted average exercise price (in dollars per share)	$ 22.89
$0.01-18.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices, lower limit (in dollars per share)	0.01
Range of exercise prices, upper limit (in dollars per share)	$ 18.00
Options outstanding, shares (in shares) \| shares	73,000
Options outstanding, weighted average remaining contractual life (years)	6 years 2 months 19 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 12.97
Options exercisable, shares (in shares) \| shares	40,666
Options exercisable, weighted average exercise price (in dollars per share)	$ 14.65
$22.01-26.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices, lower limit (in dollars per share)	22.01
Range of exercise prices, upper limit (in dollars per share)	$ 26.00
Options outstanding, shares (in shares) \| shares	28,667
Options outstanding, weighted average remaining contractual life (years)	1 year 6 months 14 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 22.90
Options exercisable, shares (in shares) \| shares	28,667
Options exercisable, weighted average exercise price (in dollars per share)	$ 22.90
$26.01-30.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices, lower limit (in dollars per share)	26.01
Range of exercise prices, upper limit (in dollars per share)	$ 30.00
Options outstanding, shares (in shares) \| shares	19,750
Options outstanding, weighted average remaining contractual life (years)	3 years 4 months 17 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 28.15
Options exercisable, shares (in shares) \| shares	19,750
Options exercisable, weighted average exercise price (in dollars per share)	$ 28.15
$30.01-34.00
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices, lower limit (in dollars per share)	30.01
Range of exercise prices, upper limit (in dollars per share)	$ 34.00
Options outstanding, shares (in shares) \| shares	30,667
Options outstanding, weighted average remaining contractual life (years)	5 months 19 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 30.41
Options exercisable, shares (in shares) \| shares	30,667
Options exercisable, weighted average exercise price (in dollars per share)	$ 30.41

Inventory

9 Months Ended

Sep. 30, 2023

Inventory Disclosure [Abstract]

Inventory

Our inventory, net of allowance for obsolescence of $40,000 at September 30, 2023 and $120,000 at December 31, 2022, consisted of the following amounts:


	September 30, 2023		December 31, 2022
	(in thousands)
Raw materials - current	$	24,587	$	21,354
Work-in-process	1,528		2,060
Inventory - current	26,115		23,414
Raw materials - long term (net of allowance of $40 and $120, respectively)	2,172		1,557
Inventory - total	$	28,287	$	24,971

Our long-term inventory consists of raw materials that remain viable but that the Company does not expect to sell or use within one year.

Inventory Allowance

We routinely review our inventory allowance balance to account for slow moving or obsolete inventory costs that may not be recoverable in the future.

A summary of our inventory allowance is as follows:


	September 30, 2023		December 31, 2022
	(in thousands)
Beginning balance	$	120	$	64
Accruals	—		83
Write-offs	(80)		(27)
Ending balance	$	40	$	120

Long-term Debt

9 Months Ended

Sep. 30, 2023

Debt Disclosure [Abstract]

Long-term Debt

Our long-term debt consists of the following:


	September 30, 2023		December 31, 2022
	(in thousands)


Total long-term debt	$	128,000	$	25,000

Amended and Restated Credit Agreement

On May 11, 2021, we entered into a five-year senior secured revolving credit agreement ("Credit Agreement") with Texas Capital Bank, National Association (the "Lender") with an initial commitment of $20 million and an accordion feature that would increase the maximum commitment to $30 million, subject to collateral availability. At December 31, 2022, we had $25 million outstanding under the Credit Agreement with a weighted average interest rate of 7.32%.

On February 28, 2023, we replaced our Credit Agreement by entering into a five-year senior secured revolving credit agreement (“Amended and Restated Credit Agreement”) with Texas Capital Bank, as administrative agent (the “Lender”), TCBI Securities, Inc., as joint lead arranger and sole book runner and Bank of America, N.A., as joint lead arranger, with an initial commitment of $175 million as of the closing date. Subject to collateral availability, we also have a right to request from the Lender, on an uncommitted basis, an increase of up to $125 million on the aggregate commitment; provided, however, the aggregate commitment amount is not permitted to exceed $300 million. The maturity date of the Amended and Restated Credit Agreement is February 28, 2028. The obligations under the Amended and Restated Credit Agreement are secured by a first priority lien on most of our assets, including inventory and accounts receivable as well as a variable number of our leased compressor equipment.

Borrowing Base. At any time before the maturity of the Amended and Restated Credit Agreement, we may draw, repay and re-borrow amounts available under the borrowing base up to the maximum aggregate availability discussed above. Generally, the borrowing base equals the sum of (a) 85% of eligible accounts receivable owed to the Company, plus (b) 50% of the eligible inventory, valued at the lower of cost or market value at such time, subject to a cap of the component not to exceed $2.5 million, plus (c) the lesser of (i) 95% of the net book value of the compressors that the Lender has determined are eligible for the extension of credit, valued at the lower of cost or market value with depreciation not to exceed 25 years, at such time and (ii) 80% of the net liquidation value percentage of the net book value of the eligible compressors that the Lender has determined are eligible for the extension of credit, valued at the lower of cost or market value with depreciation not to exceed 25 years, at such time, plus (d) 80% of the net book value, valued at the lower cost (excluding any costs for capitalized interest or other non-cash capitalized costs) or market of the eligible new compressor fleet, minus (e) any required availability reserves determined by the Lender in its sole discretion. The Lender may adjust the borrowing base components if the material deviations in the collateral are discovered in the future audits of the collateral. At September 30, 2023, our borrowing base was approximately $175 million.

Interest and Fees. Under the terms of the Amended and Restated Credit Agreement, we have the option of selecting the applicable variable rate for each revolving loan, or portion thereof, of either (a) the Base Rate (as defined below) plus the Applicable Margin, or (b) in the case of a Term SOFR ("Secured Overnight Financing Rate") Loan, the Adjusted Term SOFR rate plus the Applicable Margin. "Base Rate" means, for any day, a rate of interest per annum equal to the highest of (a) the prime rate for such a day; (b) the sum of the federal funds rate for such day plus 0.50%; and (c) the Adjusted Term SOFR for such day plus 1.00%. The Applicable Margin is determined based upon the leverage ratio as set forth in the most recent compliance certificate received by the Lender for each fiscal quarter from time to time pursuant to the Amended and Restated Credit Agreement. Depending on the leverage ratio, the Applicable Margin can be 2.00% to 2.75% for Base Rate Loans (as defined in Amended and Restated Credit Agreement) and 3.00% to 3.75% for Term SOFR Loans and for requested letters of credit. In addition, we are required to pay a monthly commitment fee on the daily average unused amount of the commitment while the Amended and Restated Credit Agreement is in effect at an annual rate equal to 0.50% of the unused commitment amount. Accrued interest is payable monthly on outstanding principal amounts and unused commitment fee, provided that accrued interest on Term SOFR Loans is payable at the end of each interest period, but in no event less frequently than quarterly.

Covenants. The Amended and Restated Credit Agreement contains customary representations and warranties, as well as covenants which, among other things, condition or limit our ability to incur additional indebtedness and liens; enter into transactions with affiliates; make acquisitions in excess of certain amounts; pay dividends; redeem or repurchase capital stock or senior notes; make investments or loans; make negative pledges; consolidate, merge or effect asset sales; or change the nature of our business. In addition, we are subject to certain financial covenants during certain trigger periods in the Amended and Restated Credit Agreement that require us to maintain (i) a leverage ratio, as defined, lesser than or equal to 3.50 to 1.00 as of the last day of each fiscal quarter thereafter and (ii) a fixed charge coverage ratio greater than or equal to 1.25 to 1.00 as of the last day of each fiscal quarter.

Events of Default and Acceleration. The Amended and Restated Credit Agreement contains customary events of default for credit facilities of this size and type, and includes, without limitation, payment defaults; defaults in performance of covenants or other agreements contained in the Amended and Restated Credit Agreement and the other transaction documents; inaccuracies in representations and warranties; certain defaults, termination events or similar events; certain defaults with respect to any other Company indebtedness in excess of $1.0 million; certain bankruptcy or insolvency events; the rendering of certain judgments in excess of $1.0 million; certain ERISA events; certain change in control events and the defectiveness of any

liens under the secured revolving credit agreement. Obligations outstanding under the Amended and Restated Credit Agreement may be accelerated upon the occurrence of an event of default.As of September 30, 2023, we were in compliance with all financial covenants in our Amended and Restated Credit Agreement. As of September 30, 2023, we had approximately $128 million outstanding under our Amended and Restated Credit Agreement with a weighted average interest rate of 8.98%. At September 30, 2023, we had approximately $47 million available for borrowing under the Amended and Restated Credit Agreement, subject to borrowing base determination.

- Definition

The entire disclosure for information about short-term and long-term debt arrangements, which includes amounts of borrowings under each line of credit, note payable, commercial paper issue, bonds indenture, debenture issue, own-share lending arrangements and any other contractual agreement to repay funds, and about the underlying arrangements, rationale for a classification as long-term, including repayment terms, interest rates, collateral provided, restrictions on use of assets and activities, whether or not in compliance with debt covenants, and other matters important to users of the financial statements, such as the effects of refinancing and noncompliance with debt covenants.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (h)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(c))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 470
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org//470/tableOfContent

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (g)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1B
-Subparagraph (i)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1B

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1C
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1C

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1C
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1C

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1C
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1C

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1E
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1E

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1I
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1I

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1I
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1I

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 1I
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481139/470-20-50-1I

+ Details

Rental Equipment (Details) - USD ($) $ in Thousands	9 Months Ended
Rental Equipment (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Property, Plant and Equipment [Line Items]
Rental equipment, gross	$ 549,177	$ 424,179
Accumulated depreciation	(193,795)	(177,729)
Rental equipment, net of accumulated depreciation	355,382	246,450
Impairment of rental equipment	0
Compressor units
Property, Plant and Equipment [Line Items]
Rental equipment, gross	494,282	387,145
Work-in-process
Property, Plant and Equipment [Line Items]
Rental equipment, gross	$ 54,895	$ 37,034

Summary of Significant Accounting Policies (Tables)

9 Months Ended

Sep. 30, 2023

Accounting Policies [Abstract]

Schedule of Disaggregation of Revenue

The following table shows the Company's revenue disaggregated by product or service type for the three and nine months ended September 30, 2023 and 2022:


	Three months ended September 30,				Nine months ended September 30,
	2023		2022		2023		2022
	(in thousands)				(in thousands)
Compressors - sales	$	207	$	1,300	$	1,214	$	3,553
Flares - sales	—		131		87		214
Other (parts/rebuilds) - sales	1,206		1,655		4,699		3,503
Aftermarket services	2,251		326		4,413		1,129
Total revenue from contracts with customers	3,664		3,412		10,413		8,399
Add: ASC 842 rental revenue	27,705		18,631		74,533		53,905
Total revenue	$	31,369	$	22,043	$	84,946	$	62,304

Schedule of Contract with Customer, Asset and Liability

As of September 30, 2023 and December 31, 2022, we had the following receivables and deferred income from contracts with customers:


	September 30, 2023		December 31, 2022
	(in thousands)
Accounts Receivable
Accounts receivable - contracts with customers	$	5,207	$	4,353
Accounts receivable - ASC 842	23,363		10,653
Total Accounts Receivable	28,570		15,006
Less: Allowance for doubtful accounts	(529)		(338)
Total Accounts Receivable, net	$	28,041	$	14,668

Deferred income	$	—	$	37

Long-term Debt - Schedule of Long-term Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
Debt Disclosure [Abstract]
Total long-term debt	$ 128,000	$ 25,000

- Definition

Amount, after deduction of unamortized premium (discount) and debt issuance cost, of long-term debt. Excludes lease obligation.

+ References + Details

Inventory - Schedule of Inventory (Details) - USD ($) $ in Thousands	Sep. 30, 2023	Dec. 31, 2022	Dec. 31, 2021
Inventory Disclosure [Abstract]
Allowance for obsolescence	$ 40	$ 120	$ 64
Raw materials - current	24,587	21,354
Work-in-process	1,528	2,060
Inventory - current	26,115	23,414
Raw materials - long term (net of allowance of $40 and $120, respectively)	2,172	1,557
Inventory - total	$ 28,287	$ 24,971

Stock-Based and Other Long-Term Incentive Compensation - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Number of Stock Options
Outstanding, beginning of period (in shares)	201,584
Granted (in shares)	1,000
Canceled/Forfeited (in shares)	(12,500)
Expired (in shares)	(38,000)
Outstanding, end of period (in shares)	152,084	201,584
Exercisable (in shares)	119,750
Weighted AverageExercise Price
Outstanding, beginning of period (in dollars per share)	$ 19.32
Granted (in dollars per share)	10.12
Canceled/Forfeited (in dollars per share)	15.60
Expired (in dollars per share)	16.28
Outstanding, end of period (in dollars per share)	20.33	$ 19.32
Exercisable (in dollars per share)	$ 22.89
WeightedAverageRemainingContractual Life (years)
Outstanding, weighted average remaining contractual life	3 years 9 months 21 days	3 years 10 months 24 days
Granted, weighted average remaining contractual life	9 years 9 months 3 days
Exercisable, weighted average remaining contractual life	2 years 6 months 29 days
AggregateIntrinsicValue(in thousands)
Outstanding, aggregate intrinsic value	$ 0	$ 41
Granted, aggregate intrinsic value	0
Cancelled / Forfeited, aggregate intrinsic value	4
Exercisable, aggregate intrinsic value	$ 0

Condensed Consolidated Balance Sheets (Parentheticals) - USD ($) shares in Thousands, $ in Thousands	Sep. 30, 2023	Dec. 31, 2022
ASSETS
Allowance for doubtful accounts	$ 529	$ 338
Allowance for obsolescence	40	120
Accumulated depreciation, rental equipment	193,795	177,729
Accumulated depreciation, property and equipment	17,737	16,981
Accumulated amortization, operating lease right of use assets	864	721
Accumulated amortization, intangibles	$ 2,353	$ 2,259
Stockholders’ Equity:
Preferred stock, shares authorized (in shares)	5,000	5,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, shares authorized (in shares)	30,000	30,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares issued (in shares)	13,688	13,519
Treasury shares (in shares)	1,310	1,310

Summary of Significant Accounting Policies - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 3,664	$ 3,412	$ 10,413	$ 8,399
Add: ASC 842 rental revenue	27,705	18,631	74,533	53,905
Total revenue	31,369	22,043	84,946	62,304
Compressors - sales
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	207	1,300	1,214	3,553
Flares - sales
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	131	87	214
Other (parts/rebuilds) - sales
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,206	1,655	4,699	3,503
Aftermarket services
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 2,251	$ 326	$ 4,413	$ 1,129

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References + Details

- Definition

Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 924
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 11.L)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479941/924-10-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 5
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-5

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 30
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-30

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 42
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-42

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 22
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-22

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-32

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 40
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-40

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 22
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-22

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-32

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 41
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-41

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 606
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 4
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479806/606-10-50-4

+ Details

- Definition

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(g)(1)(ii))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 323
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 3
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481687/323-10-50-3

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 28
-Subparagraph (f)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482907/825-10-50-28

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 220
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03(1))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147483621/220-10-S99-2

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(i))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A

Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(ii))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(iii)(A))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(4)(iv))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1A
-Subparagraph (SX 210.13-01(a)(5))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1A

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(i))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B

Reference 11: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iii)(A))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B

Reference 12: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iii)(B))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B

Reference 13: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(4)(iv))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B

Reference 14: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1B
-Subparagraph (SX 210.13-02(a)(5))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480097/470-10-S99-1B

Reference 15: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 30
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-30

Reference 16: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 42
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-42

Reference 17: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 22
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-22

Reference 18: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-32

Reference 19: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 40
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-40

Reference 20: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 22
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-22

Reference 21: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 32
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-32

Reference 22: http://www.xbrl.org/2003/role/disclosureRef
-Topic 280
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 41
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482810/280-10-50-41

Reference 23: http://www.xbrl.org/2003/role/disclosureRef
-Topic 942
-SubTopic 235
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-05(b)(2))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479557/942-235-S99-1

+ Details

Stock-Based and Other Long-Term Incentive Compensation - Summary of Unvested Stock Options (Details)	9 Months Ended
	Sep. 30, 2023 $ / shares shares
Shares
Unvested, beginning of period (in shares) \| shares	39,000
Granted (in shares) \| shares	1,000
Vested, outstanding shares (in shares) \| shares	(3,332)
Canceled/Forfeited (in shares) \| shares	(4,334)
Unvested, end of period (in shares) \| shares	32,334
Weighted Average Grant Date Fair Value Per Share
Unvested, weighted average grant date fair value, beginning of period (in dollars per share) \| $ / shares	$ 5.44
Granted (in dollar per share) \| $ / shares	5.30
Vested, outstanding shares (in dollars per share) \| $ / shares	6.26
Canceled/Forfeited (in dollars per share) \| $ / shares	5.15
Unvested, weighted average grant date fair value, end of period (in dollars per share) \| $ / shares	$ 5.38

Long-term Debt (Tables)

9 Months Ended

Sep. 30, 2023

Debt Disclosure [Abstract]

Schedule of Long-Term Debt Instruments

Our long-term debt consists of the following:


	September 30, 2023		December 31, 2022
	(in thousands)


Total long-term debt	$	128,000	$	25,000

- Definition

Tabular disclosure of long-debt instruments or arrangements, including identification, terms, features, collateral requirements and other information necessary to a fair presentation. These are debt arrangements that originally required repayment more than twelve months after issuance or greater than the normal operating cycle of the entity, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 69B
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481568/470-20-55-69B

Reference 2: http://www.xbrl.org/2003/role/exampleRef
-Topic 470
-SubTopic 20
-Name Accounting Standards Codification
-Section 55
-Paragraph 69E
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481568/470-20-55-69E

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 3
-Subparagraph (SX 210.12-04(a))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-3

Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482925/835-30-45-2

Reference 5: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 1A
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482925/835-30-45-1A

Reference 6: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-3

Reference 7: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480566/210-10-S99-1

Reference 8: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482949/835-30-55-8

Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480848/942-470-50-3

Reference 10: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 8
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-8

Reference 11: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-6

Reference 12: http://fasb.org/us-gaap/role/ref/legacyRef
-Topic 505
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 7
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147481112/505-10-50-7

+ Details

Summary of Significant Accounting Policies - Contract Balances (Details) - USD ($)	Sep. 30, 2023	Dec. 31, 2022
Accounts Receivable
Accounts receivable - contracts with customers	$ 5,207,000	$ 4,353,000
Accounts receivable - ASC 842	23,363,000	10,653,000
Total Accounts Receivable	28,570,000	15,006,000
Less: Allowance for doubtful accounts	(529,000)	(338,000)
Total Accounts Receivable, net	28,041,000	14,668,000
Deferred income	$ 0	$ 37,000

Commitments and Contingencies	9 Months Ended
Commitments and Contingencies	Sep. 30, 2023
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and ContingenciesFrom time to time, we are a party to various legal proceedings in the ordinary course of our business. We are not currently a party to any material legal proceedings, and we are not aware of any threatened material litigation. The Company believes it maintains adequate insurance coverage against any potential litigation loss.

Rental Equipment (Tables)

9 Months Ended

Sep. 30, 2023

Property, Plant and Equipment [Abstract]

Schedule of Rental Equipment

Our rental equipment and associated accumulated depreciation as of September 30, 2023 and December 31, 2022, respectively, consisted of the following:


	September 30, 2023		December 31, 2022
	(in thousands)
Compressor units	$	494,282	$	387,145
Work-in-process	54,895		37,034
Rental equipment	549,177		424,179
Accumulated depreciation	(193,795)		(177,729)
Rental equipment, net of accumulated depreciation	$	355,382	$	246,450

Federal Income Tax Receivable	9 Months Ended
Federal Income Tax Receivable	Sep. 30, 2023
Income Tax Disclosure [Abstract]
Federal Income Tax Receivable	Federal Income Tax ReceivableOn March 27, 2020, the Coronavirus Aid, Relief, and Economic Security Act ("CARES Act") was enacted in response to the economic impact caused by the COVID-19 pandemic. The CARES Act allowed NOLs incurred in 2018, 2019, and 2020 to be carried back to each of the five preceding taxable years to generate a refund of previously paid federal income taxes. The Company generated significant NOLs during 2018 and 2019, and has filed amended returns to carryback these losses for five years. Accordingly, during 2020, the Company recorded a federal income tax receivable of $15.0 million and an increase to its deferred income tax liability of $10.1 million on its condensed consolidated balance sheet. During the third quarter of 2020, the Company received refunds totaling $3.9 million related to its 2018 NOLs, which reduced its federal income tax receivable to $11.5 million on its condensed consolidated balance sheet as of September 30, 2023 and December 31, 2022.

- Definition

The entire disclosure for income taxes. Disclosures may include net deferred tax liability or asset recognized in an enterprise's statement of financial position, net change during the year in the total valuation allowance, approximate tax effect of each type of temporary difference and carryforward that gives rise to a significant portion of deferred tax liabilities and deferred tax assets, utilization of a tax carryback, and tax uncertainties information.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 946
-SubTopic 20
-Name Accounting Standards Codification
-Section 50
-Paragraph 13
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480990/946-20-50-13

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Topic 235
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08(h)(2))
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147480678/235-10-S99-1

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-Name Accounting Standards Codification
-Publisher FASB
-URI https://asc.fasb.org//740/tableOfContent

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 14
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-14

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 21
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-21

Reference 6: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 270
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482526/740-270-50-1

Reference 7: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 17
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482685/740-10-50-17

Reference 8: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 1
-Subparagraph (SAB TOPIC 6.I.5.Q1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479360/740-10-S99-1

Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section S99
-Paragraph 2
-Subparagraph (SAB Topic 11.C)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479360/740-10-S99-2

Reference 10: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482603/740-30-50-2

+ Details

Stock-Based and Other Long-Term Incentive Compensation - Restricted Stock (Details) - Restricted Stock - USD ($) $ / shares in Units, $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2023	Dec. 31, 2022
Number of Shares
Outstanding, beginning of period (in shares)	250,847
Granted (in shares)	153,656
Vested (in shares)	(267,232)
Canceled/Forfeited (in shares)	(14,357)
Outstanding, beginning of period (in shares)	122,914	250,847
Weighted Average Grant Date Fair Value
Outstanding beginning of period (in dollars per share)	$ 8.40
Granted (in dollars per share)	10.41
Vested (in dollars per share)	9.22
Canceled/Forfeited (in dollars per share)	10.04
Outstanding ending of the period (in dollars per share)	$ 10.29	$ 8.40
Weighted Average Remaining Contractual Life (years)
Weighted average remaining contractual life (years)	4 years 10 months 2 days	1 year 5 months 1 day
Aggregate Intrinsic Value
Outstanding, begging balance	$ 2,681
Granted	1,599
Vested	2,683
Canceled/Forfeited	158
Outstanding, ending balance	$ 1,482	$ 2,681

Cover - shares	9 Months Ended
Cover - shares	Sep. 30, 2023	Nov. 09, 2023
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2023
Document Transition Report	false
Entity File Number	1-31398
Entity Registrant Name	NATURAL GAS SERVICES GROUP, INC.
Entity Incorporation, State or Country Code	CO
Entity Tax Identification Number	75-2811855
Entity Address, Address Line One	404 Veterans Airpark Ln., Ste 300
Entity Address, City or Town	Midland
Entity Address, State or Province	TX
Entity Address, Postal Zip Code	79705
City Area Code	432
Local Phone Number	262-2700
Title of 12(b) Security	Common Stock, Par Value $0.01
Trading Symbol	NGS
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		12,437,292
Entity Central Index Key	0001084991
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2023
Document Fiscal Period Focus	Q3
Amendment Flag	false

Federal Income Tax Receivable (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Sep. 30, 2020	Dec. 31, 2020	Sep. 30, 2023	Dec. 31, 2022
Income Tax Disclosure [Abstract]
Federal income tax receivable		$ 15,000	$ 11,538	$ 11,538
Deferred tax liability increase due to tax law change		$ 10,100
Income tax received refunds	$ 3,900

Stock-Based and Other Long-Term Incentive Compensation - Other Long-Term Incentive Compensation, Narrative (Details) - Other Long-Term Incentive Compensation $ in Thousands		9 Months Ended
	Apr. 26, 2022 USD ($) independent_director	Sep. 30, 2023 USD ($)	Sep. 30, 2022 USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense		$ 426	$ 672
Directors
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted	$ 50
Number of independent directors \| independent_director	3

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

+ Details

Inventory (Tables)

9 Months Ended

Sep. 30, 2023

Inventory Disclosure [Abstract]

Schedule of Inventory

Our inventory, net of allowance for obsolescence of $40,000 at September 30, 2023 and $120,000 at December 31, 2022, consisted of the following amounts:


	September 30, 2023		December 31, 2022
	(in thousands)
Raw materials - current	$	24,587	$	21,354
Work-in-process	1,528		2,060
Inventory - current	26,115		23,414
Raw materials - long term (net of allowance of $40 and $120, respectively)	2,172		1,557
Inventory - total	$	28,287	$	24,971

A summary of our inventory allowance is as follows:


	September 30, 2023		December 31, 2022
	(in thousands)
Beginning balance	$	120	$	64
Accruals	—		83
Write-offs	(80)		(27)
Ending balance	$	40	$	120

Earnings (loss) per Share (Tables)

9 Months Ended

Sep. 30, 2023

Earnings Per Share [Abstract]

Schedule of Earnings Per Share, Basic and Diluted

The following table reconciles the numerators and denominators of the basic and diluted earnings per share computation:


	Three months ended				Nine months ended
	September 30,				September 30,
	2023		2022		2023		2022
	(in thousands, except per share data)
Numerator:
Net income (loss)	$	2,171	$	(80)	$	3,045	$	187
Denominator for earnings per basic common share:
Weighted average common shares outstanding	12,378		12,192		12,295		12,344
Denominator for earnings per diluted common share:
Weighted average common shares outstanding	12,378		12,192		12,295		12,344
Dilutive effect of stock options and restricted stock/units	25		—		77		90
Diluted weighted average shares	12,403		12,192		12,372		12,434
Earnings (loss) per common share:
Basic	$	0.18	$	(0.01)	$	0.25	$	0.02
Diluted	$	0.18	$	(0.01)	$	0.25	$	0.02

Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Revenue:
Rental income	$ 27,705	$ 18,631	$ 74,533	$ 53,905
Revenue from contracts with customers	3,664	3,412	10,413	8,399
Total revenue	31,369	22,043	84,946	62,304
Operating costs and expenses:
Cost of rentals, exclusive of depreciation stated separately below	13,462	9,988	36,450	28,460
Cost of sales, exclusive of depreciation stated separately below	1,505	2,083	6,618	5,512
Cost of aftermarket services, exclusive of depreciation stated separately below	1,846	186	3,424	593
Selling, general and administrative expenses	2,845	4,064	12,267	8,875
Depreciation and amortization	6,807	6,016	19,390	18,118
Impairment expense	0	0	779	0
Total operating costs and expenses	26,465	22,337	78,928	61,558
Operating income (expense)	4,904	(294)	6,018	746
Other income (expense):
Interest expense	(1,600)	(25)	(1,785)	(74)
Other income (expense), net	(87)	166	254	(197)
Total other income (expense), net	(1,687)	141	(1,531)	(271)
Income (loss) before provision for income taxes	3,217	(153)	4,487	475
Income tax (expense) benefit	(1,046)	73	(1,442)	(288)
Net income (loss)	$ 2,171	$ (80)	$ 3,045	$ 187
Earnings (loss) per share:
Basic (in dollars per share)	$ 0.18	$ (0.01)	$ 0.25	$ 0.02
Diluted (in dollars per share)	$ 0.18	$ (0.01)	$ 0.25	$ 0.02
Weighted average shares outstanding:
Basic (in shares)	12,378	12,192	12,295	12,344
Diluted (in shares)	12,403	12,192	12,372	12,434
Sales
Revenue:
Revenue from contracts with customers	$ 1,413	$ 3,086	$ 6,000	$ 7,270
Aftermarket services
Revenue:
Revenue from contracts with customers	$ 2,251	$ 326	$ 4,413	$ 1,129