Natural Gas Services (NGS) 10-K 31 Mar 21 2020 FY Annual report Financial data

Cover

Cover - USD ($)	12 Months Ended
	Dec. 31, 2020	Mar. 26, 2021	Jun. 30, 2020
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Dec. 31, 2020
Current Fiscal Year End Date	--12-31
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 Lane, Suite 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, $.01 par value
Trading Symbol	NGS
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
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 Public Float			$ 82,414,178
Entity Common Stock, Shares Outstanding		13,605,803
Documents Incorporated by Reference	Documents incorporated by reference Certain information called for in Items 10, 11, 12, 13 and 14 of Part III are incorporated by reference to the registrant’s definitive proxy statement for the annual meeting of shareholders expected to be held on June 17, 2021.
Entity Central Index Key	0001084991
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current Assets:
Cash and cash equivalents	$ 28,925	$ 11,592
Trade accounts receivable, net of allowance for doubtful accounts of $1,161 and $918, respectively	11,884	9,106
Inventory	19,926	21,080
Federal income tax receivable	11,538	0
Prepaid income taxes	66	40
Prepaid expenses and other	379	597
Total current assets	72,718	42,415
Long-Term Inventory, net of allowance for obsolescence of $221 and $24, respectively	1,065	1,068
Rental equipment, net of accumulated depreciation of $175,802 and $162,348, respectively	207,585	217,742
Property and equipment, net of accumulated depreciation of $13,916 and $12,847, respectively	21,749	21,869
Right of use assets - operating leases, net of accumulated amortization $356	483	604
Intangibles, net of accumulated amortization of $2,008 and $1,883, respectively	1,151	1,276
Other assets	2,050	1,603
Total assets	306,801	286,577
Current Liabilities:
Accounts payable	2,373	1,975
Accrued liabilities	6,770	2,287
Line of credit	417	417
Current operating leases	198	189
Deferred income	1,103	640
Total current liabilities	10,861	5,508
Deferred income tax liability	41,890	31,243
Long-term operating leases	285	415
Other long-term liabilities	2,221	1,718
Total liabilities	55,257	38,884
Commitments and contingencies
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; 13,296 and 13,178 shares issued, respectively	133	132
Additional paid-in capital	112,615	110,573
Retained earnings	139,286	137,478
Treasury shares, at cost, 38 shares	(490)	(490)
Total stockholders' equity	251,544	247,693
Total liabilities and stockholders' equity	$ 306,801	$ 286,577

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Current Assets:
Allowance for doubtful accounts	$ 1,161	$ 918
Allowance for inventory obsolescence	221	24
Assets, Noncurrent [Abstract]
Accumulated depreciation, rental equipment	175,802	162,348
Accumulated depreciation, property and equipment	13,916	12,847
Accumulated amortization, operating lease right of use assets	356
Accumulated amortization, intangibles	$ 2,008	$ 1,883
Stockholders’ Equity:
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0
Common stock, shares authorized (in shares)	30,000,000	30,000,000
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares issued (in shares)	13,296,000	13,178,000
Common stock, shares outstanding (in shares)	13,296,000	13,178,000
Treasury shares (in shares)	38,000

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Revenue:
Revenues	$ 68,055	$ 78,444
Operating costs and expenses:
Cost of rentals, exclusive of depreciation stated separately below	28,506	27,583
Cost of sales, exclusive of depreciation stated separately below	6,211	16,097
Cost of service and maintenance, exclusive of depreciation stated separately below	714	630
Selling, general and administrative expenses	10,550	10,710
Depreciation and amortization	25,198	23,268
Impairment of goodwill	0	10,039
Inventory allowance	184	3,758
Retirement of rental equipment	291	1,512
Total operating costs and expenses	71,654	93,597
Operating loss	(3,599)	(15,153)
Other income (expense):
Interest expense	(14)	(15)
Other income	629	611
Total other income, net	615	596
Loss before income taxes:	(2,984)	(14,557)
(Provision for) benefit from income taxes:
Current	15,438	31
Deferred	(10,646)	662
Total income tax benefit	4,792	693
Net income (loss)	$ 1,808	$ (13,864)
Earnings (loss) per share:
Basic (in dollars per share)	$ 0.14	$ (1.06)
Diluted (in dollars per share)	$ 0.14	$ (1.06)
Weighted average shares outstanding:
Basic (in shares)	13,224	13,114
Diluted (in shares)	13,261	13,114
Loss On Retirement of Rental Equipment
Operating costs and expenses:
Retirement of rental equipment	$ 291	$ 1,512
Rental income
Revenue:
Revenues	60,826	56,701
Sales
Revenue:
Revenues	5,657	19,763
Service and maintenance income
Revenue:
Revenues	$ 1,572	$ 1,980

CONSOLIDATED STATEMENTS OF STOC

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, 2018		0	13,005			0
Beginning balance at Dec. 31, 2018	$ 259,232	$ 0	$ 130	$ 107,760	$ 151,342	$ 0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Exercise of common stock options (in shares)			56
Exercise of common stock options	506		$ 1	505
Compensation expense on common stock options	124			124
Issuance of restricted stock (in shares)			117
Compensation expense on restricted common stock	2,458		$ 1	2,457
Taxes paid related to net shares settlement of equity awards	(273)			(273)
Purchase of treasury shares (in shares)						38
Purchase of treasury shares	(490)					$ (490)
Net loss	(13,864)				(13,864)
Ending balance (in shares) at Dec. 31, 2019		0	13,178			(38)
Ending balance at Dec. 31, 2019	247,693	$ 0	$ 132	110,573	137,478	$ (490)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Compensation expense on common stock options	19			19
Issuance of restricted stock (in shares)			118
Compensation expense on restricted common stock	2,176		$ 1	2,175
Taxes paid related to net shares settlement of equity awards	(152)			(152)
Net loss	1,808				1,808
Ending balance (in shares) at Dec. 31, 2020		0	13,296			(38)
Ending balance at Dec. 31, 2020	$ 251,544	$ 0	$ 133	$ 112,615	$ 139,286	$ (490)

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
CASH FLOWS FROM OPERATING ACTIVITIES:
Net (loss) income	$ 1,808,000	$ (13,864,000)
Adjustments to reconcile net (loss) income to net cash provided by operating activities:
Depreciation and amortization	25,198,000	23,268,000
Deferred taxes	10,646,000	(662,000)
Gain on disposal of assets	(284,000)	(55,000)
Retirement of rental equipment	291,000	1,512,000
Bad debt allowance (recovery)	329,000	664,000
Inventory allowance	184,000	3,758,000
Impairment of goodwill	0	10,039,000
Stock-based compensation	2,195,000	2,582,000
(Gain) loss on company owned life insurance	(168,000)	(218,800)
Changes in operating assets and liabilities:
Trade accounts receivables	(3,107,000)	(2,550,000)
Inventory	1,033,000	8,256,000
Prepaid income taxes and prepaid expenses	(11,346,000)	3,288,000
Accounts payable and accrued liabilities	4,880,000	(7,225,000)
Deferred income	463,000	559,000
Other	527,000	61,000
NET CASH PROVIDED BY OPERATING ACTIVITIES	32,649,000	29,412,000
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchase of rental equipment, property and other equipment	(15,257,000)	(69,938,000)
Purchase of company owned life insurance	(296,000)	(302,000)
Proceeds from insurance claim	0	35,000
Proceeds from sale of property and equipment	394,000	30,000
NET CASH USED IN INVESTING ACTIVITIES	(15,159,000)	(70,175,000)
CASH FLOWS FROM FINANCING ACTIVITIES:
Proceeds of other long-term liabilities	(5,000)	(16,000)
Proceeds from exercise of stock options	0	506,000
Purchase of treasury shares	0	(490,000)
Taxes paid related to net share settlement of equity awards	(152,000)	(273,000)
NET CASH USED IN FINANCING ACTIVITIES	(157,000)	(273,000)
NET CHANGE IN CASH AND CASH EQUIVALENTS	17,333,000	(41,036,000)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	11,592,000	52,628,000
CASH AND CASH EQUIVALENTS AT END OF PERIOD	28,925,000	11,592,000
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
Interest paid	14,000	39,000
Income taxes paid	105,000	275,000
NON-CASH TRANSACTIONS
Transfer of rental equipment to inventory	0	836,000
Transfer of inventory to rental equipment	0	1,184,000
Transfer of prepaids to rental equipment and inventory	0	958,000
Right of use asset acquired through an operating lease	$ 77,000	$ 762,000

Description of Business

Description of Business	12 Months Ended
	Dec. 31, 2020
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 and services to the energy industry. The Company manufactures, fabricates, rents, sells and maintains natural gas compressors and flare 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 was formed on December 17, 1998.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies Principles of Consolidation The accompanying 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, see Note 12. All significant intercompany accounts and transactions for the periods presented have been eliminated in consolidation. Use of Estimates The preparation of our consolidated financial statements in conformity with generally accepted accounting principles in the United States of America requires our management to make estimates and assumptions that affect the amounts reported in these consolidated financial statements and accompanying notes. Actual results could differ from those estimates. Significant estimates include fixed asset lives, bad debt allowance and the allowance for inventory obsolescence. Additionally, NGS conducts a yearly review of impairment of long-lived assets. Throughout the review, determining factors are based on estimates that can significantly impact the carrying value of these assets. It is at least reasonably possible these estimates could be revised in the near term and the revisions could be material. Cash Equivalents and Financial Instruments For purposes of reporting cash flows, we consider all short-term investments with an original maturity of three months or less to be cash equivalents. We invest our cash primarily in deposits and money market funds with commercial banks. At times, cash balances at banks and financial institutions may exceed federally insured amounts. We believe that the risk to our cash balance is minimal because we have chosen a large bank with strong long-term ratings of Aa2/A+. Accounts Receivable Our trade receivables consist of customer obligations for the sale of compressors and flare systems due under normal trade terms, and operating leases for the use of our natural gas compressors. The receivables are not collateralized except as provided for under lease agreements. However, we typically require deposits of as much as 50% or use of progress payments for large custom sales contracts. We perform ongoing credit evaluations of our customers and adjust credit limits based on management's assessment of the customer's financial condition and payment history, as well as industry conditions and general economic conditions. We continuously monitor collections and payments from our customers, and maintain a provision for estimated credit losses based upon our historical experience and any specific customer collection issues that we have identified. While such credit losses have historically been within our expectations and the provisions established, we cannot guarantee that we will continue to experience the same credit loss rates that we have in the past. One customer accounted for 35% of our accounts receivable as of December 31, 2020 and 2019. A significant change in the liquidity or financial position of this customer could have a material adverse impact on the collectability of our accounts receivable and our future operating results. The allowance for doubtful accounts was $1.2 million and $0.9 million at December 31, 2020 and 2019, respectively. Management believes that the allowance is adequate; however, actual write-offs may exceed the recorded allowance. A summary of our allowance for doubtful accounts is as follows: Year Ended December 31, ($ in thousands) 2020 2019 Beginning balance $ (918) $ (291) Accruals (329) (664) Recoveries — — Write-offs 86 37 Ending balance $ (1,161) $ (918) Revenue Recognition Policy 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 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 compressors and flare 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 or flare during the rental contract. Our rental contracts typically range from six Sales Revenue. The Company generates revenue by the sale of custom/fabricated compressors, flare systems and parts, as well as, exchange/rebuilding customer owned compressors and sale of used rental equipment. Custom/fabricated compressors and flare systems - The Company designs and fabricates compressors and flares 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 or flare package is completed and shipped, or in accordance with a bill and hold arrangements 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 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, upon the customer’s written request, 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 we ship the equipment per their direction from our manufacturing facility at a later specified date and that we segregate the equipment from our finished goods, such that they are 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 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 shouldered by the customer and there are no exceptions to the customer’s commitment to accept and pay for the manufactured equipment. Revenues recognized related to bill and hold arrangements for the years ended December 31, 2020 and 2019 was approximately $0.9 million and $11.6 million, respectively. 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 or flares - From time to time, a customer may request to purchase a used compressor or flare 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. Service and Maintenance Revenue. The Company provides routine or call-out services on customer owned equipment. Revenue is recognized after services in the contract are rendered. Payment terms for sales revenue and service and maintenance revenue discussed above are generally 30 to 60 days although terms for specific customers can vary. Also, the 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 years ended: Year Ended December 31, 2020 2019 (in thousands) Compressors - sales $ 2,211 $ 15,185 Flares - sales 489 959 Other (Parts/Rebuilds) - sales 2,957 3,619 Service and maintenance 1,572 1,980 Total revenue from contracts with customers 7,229 21,743 Add: ASC 842 rental revenue 60,826 56,701 Total revenue $ 68,055 $ 78,444 Contract Balances As of December 31, 2020 and 2019, we had the following receivables and deferred income from contracts with customers: December 31, 2020 2019 (in thousands) Accounts Receivable Accounts receivable - contracts with customers $ 3,243 $ 3,061 Accounts receivable - ASC 842 9,802 6,963 Total Accounts Receivable 13,045 10,024 Less: Allowance for doubtful accounts (1,161) (918) Total Accounts Receivable, net 11,884 9,106 Deferred income $ 1,103 $ 640 The Company recognized $73,000 in revenue for the year ended December 31, 2020 that was included in deferred income at the beginning of 2020. For the period ended December 31, 2019, the Company recognized revenue of $48,000 from amounts related to sales that were included in deferred income at the beginning of 2019. The increases (decreases) of accounts receivable and deferred income were primarily due to normal timing differences between our performance and the customers’ payments. T ransaction Price Allocated to the Remaining Performance Obligations As of December 31, 2020, the Company did not have 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 expense on our Consolidated Statements of Operations. Leases On January 1, 2019, we adopted ASC 842 using the modified retrospective method. We recognized the cumulative effect of initially applying the new lease standard and had no adjustments to retained earnings. The comparative information has not been restated and continues to be reported under the lease accounting standard in effect for those periods. The new lease standard requires all leases to be reported on the balance sheet as right-of-use assets and lease obligations. We elected the practical expedients permitted under the transition guidance of the new standard that retained the lease classification and initial direct costs for any leases that existed prior to adoption of the standard. We did not reassess whether any contracts or land easements entered into prior to adoption are leases or contain leases. The cumulative effect of the changes made to our consolidated balance sheet at January 1, 2019, for the adoption of ASC 842 was as follows: Balance at December 31, 2018 Adjustments due to ASC 842 Balance at January 1, 2019 (in thousands) Balance Sheet Assets Right of use assets $ — $ 451 $ 451 Liabilities Current portion of operating leases $ — $ 126 $ 126 Long term portion of operating leases — 325 325 Total lease liabilities $ — $ 451 $ 451 The Company, as a lessee, applies the practical expedient to not separate non-lease components from lease components, therefore, accounting for each separate lease component and its associated non-lease component, as a single lease component. Each lease that 1) contains the same timing and pattern of transfer for lease and non-lease components; and 2) if the lease component, if accounted for separately, would be classified as an operating lease, the Company elects to not separate non-lease components from lease components. Major Customers and Concentration of Credit Risk Sales and rental income from Occidental Permian, LTD. ("Oxy") in 2020 and 2019 amounted to 30% and 36% of revenue, respectively. No other single customer accounted for more than 10% of our revenues in 2020 and 2019. Oxy's accounts receivable balances amounted to 35% and 35% of our accounts receivable as of December 31, 2020 and 2019, respectively. No other customers amounted to more than 10% of our accounts receivable as of December 31, 2020 and 2019. Inventory Inventory (current and long-term) is valued at the lower of cost and net realizable value. The cost of inventories is determined by the weighted average method. We regularly review inventory quantities on hand and record a provision for excess and obsolete inventory based primarily on current and anticipated customer demand and production requirements. The Company assesses anticipated customer demand based on current and upcoming capital expenditure budgets of its major customers as well as other significant companies in the industry, along with oil and natural gas price forecasts and other factors affecting the industry. In addition, our long-term inventory consists of raw materials that remain viable but which the Company does not expect to sell within the next year. Rental Equipment and Property and Equipment Rental equipment and property and equipment are recorded at cost less accumulated depreciation, except for work-in-progress on new rental equipment which is recorded at cost until it’s complete and added to the fleet. Depreciation is computed using the straight-line method over the estimated useful lives of the assets. Our rental equipment has an estimated useful life between 15 and 25 years, while our property and equipment has an estimate useful lives which range from 3 to 39 years. The majority of our property and equipment, including rental equipment, is a direct cost to generating revenue. We assess the impairment of rental equipment and property and equipment whenever events or changes in circumstances indicate that the net recorded amount may not be recoverable. The following factors could trigger an impairment review: significant underperformance relative to historical or projected future cash flows; significant adverse changes in the extent or manner in which asset (or asset group) is being used or its condition, including a meaningful drop in fleet utilization over the prior four quarters; significant negative industry or company-specific trends or actions, including meaningful capital expenditure budget reductions by our major customers or other sizable exploration and production or midstream companies, as well as significant declines in oil and natural gas prices; legislative changes prohibiting us from leasing our units or flares; or poor general economic conditions. An impairment loss is recognized if the future undiscounted cash flows associated with the asset (or asset group) and the estimated fair value of the asset are less than the asset's carrying value. Sales of equipment out of the rental fleet are included with sales revenue and cost of sales, while retirements of units are shown a separate operating expense. Gains and losses resulting from sales and dispositions of other property and equipment are included with other income. Maintenance and repairs are charged to cost of rentals as incurred. Goodwill Goodwill represents the cost in excess of fair value of the identifiable net assets acquired. Goodwill is tested annually for impairment or as needed upon the occurrence of certain events or substantive changes in circumstances that indicate goodwill is more likely than not impaired. As further described in Note 7 of these financial statements, we fully impaired the Company's goodwill during the third quarter of 2019, resulting in a goodwill impairment charge of $10.0 million for the year ended December 31, 2019. Intangibles At December 31, 2020 and 2019, NGS had intangible assets, which relate to developed technology and a trade name. Developed technology is amortized on a straight-line basis with a useful life of 20 years, with a weighted average remaining life of approximately five years as of December 31, 2020. NGS has an intangible asset related to the trade name of SCS which was acquired in our acquisition of Screw Compression Systems in January 2005. This asset is not being amortized as it has been deemed to have an indefinite life. Our policy is to review intangibles that are being amortized for impairment when indicators of impairment are present. In addition, it is our policy to review indefinite-lived intangible assets for impairment annually or when indicators of impairment are present. We review intangibles through an assessment of the estimated future cash flows related to such assets. In the event that assets are found to be carried at amounts in excess of estimated undiscounted future cash flows, then the assets will be adjusted for impairment to a level commensurate with a discounted cash flow analysis of the underlying assets. Warranty We accrue amounts for estimated warranty claims based upon current and historical product warranty costs and any other related information known. There was no warranty reserve as of December 31, 2020. The warranty reserve was $74,000 for December 31, 2019, and is included in accrued liabilities on the consolidated balance sheet. 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 carry-forwards. 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. We assess the likelihood that our deferred tax assets will be recovered from future taxable income and, to the extent we believe that recovery is not probable, we establish a valuation allowance. To the extent we establish a valuation allowance or increase this allowance in a period, we include an expense in the tax provision in the statement of income. ASC Topic 740 prescribes a recognition threshold and measurement attribute for the financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return. In order to record any financial statement benefit, we are required to determine, based on technical merits of the position, whether it is more likely than not (a likelihood of more than 50 percent) that a tax position will be sustained upon examination, including resolution of any related appeals or litigation processes. If that step is satisfied, then we must measure the tax position to determine the amount of benefit to recognize in the financial statements. The tax position is measured at the largest amount of the benefit that is greater than 50 percent likely of being realized upon ultimate settlement. Our policy regarding income tax interest and penalties is to expense those items as other expense. We account for uncertain tax positions in accordance with guidance in FASB 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 financial statements. We have no uncertain tax positions as of December 31, 2020. Fair Value Measurement Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date under current market conditions. ASC Topic 820 established a fair value hierarchy, which requires an entity to maximize the use of observable inputs when measuring fair value. These inputs are categorized as follows: Level 1- quoted prices in an active market for identical assets or liabilities; Level 2- quoted prices in an active market for similar assets or liabilities, inputs other than quoted prices that are observable for similar assets or liabilities, inputs derived principally from or corroborated by observable market data by correlation or other means; and Level 3- valuation methodology with unobservable inputs that are significant to the fair value measurement. Management believes that the fair value of our cash and cash equivalents, trade receivables, accounts payable and line of credit at December 31, 2020 and 2019 approximate their carrying values due to the short-term nature of the instruments or the use of prevailing market interest rates. Segments and Related Information ASC 280-10-50, “Operating Segments”, define the characteristics of an operating segment as a) being engaged in business activity from which it may earn revenue and incur expenses, b) being reviewed by the company's chief operating decision maker (CODM) for decisions about resources to be allocated and assess its performance and c) having discrete financial information. Although we indeed look at our products to analyze the nature of our revenue, other financial information, such as certain costs and expenses, net income and EBITDA are not captured or analyzed by these categories. Our CODM does not make resource allocation decisions or access the performance of the business based on these categories, but rather in the aggregate. Based on this, management believes that it operates in one business segment. In their analysis of product lines as potential operating segments, management also considered ASC 280-10-50-11, “Aggregation Criteria”, which allows for the aggregation of operating segments if the segments have similar economic characteristics and if the segments are similar in each of the following areas: • The nature of the products and services; • The nature of the production processes; • The type or class of customer for their products and services; • The methods used to distribute their products or provide their services; and • The nature of the regulatory environment, if applicable. We are engaged in the business of designing and manufacturing compressors and flares. Our compressors and flares are sold and rented to our customers. In addition, we provide service and maintenance on compressors in our fleet and to third parties. These business activities are similar in all geographic areas. Our manufacturing process is essentially the same for the entire Company and is performed in house at our facilities in Midland, Texas and Tulsa, Oklahoma. Our customers primarily consist of entities in the business of producing natural gas. The maintenance and service of our products is consistent across the entire Company and is performed via an internal fleet of vehicles. The regulatory environment is similar in every jurisdiction in that the most impacting regulations and practices are the result of federal energy policy. In addition, the economic characteristics of each customer arrangement are similar in that we maintain policies at the corporate level. Recently Issued Accounting Pronouncements In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform, which provides temporary optional guidance to companies impacted by the transition away from the London Interbank Offered Rate ("LIBOR"). The guidance provides certain expedients and exceptions to applying GAAP in order to lessen the potential accounting burden when contracts, hedging relationships and other transactions that reference LIBOR as a benchmark rate are modified. This guidance is effective upon issuance and expires on December 31, 2022. We are currently evaluating the impact of the LIBOR transition and this ASU 2020-04 on our consolidated financial statements. In December 2019, the FASB issued ASU 2019-12, Income Taxes (ASC Topic 740), which simplifies accounting for income taxes by removing certain exceptions to various tax accounting principles and clarifies other existing guidance in order to improve consistency of application. These amendments are effective for public entities for interim and annual periods beginning after December 15, 2020. We are currently evaluating the impact of ASU 2019-12 on our consolidated financial statements and note disclosures.

Inventory

Inventory	12 Months Ended
	Dec. 31, 2020
Inventory Disclosure [Abstract]
Inventory	InventoryOur inventory, net of allowance for obsolescence of $221,000 and $24,000 at December 31, 2020 and 2019, respectively, consisted of the following: December 31, 2020 2019 (in thousands) Raw materials - current $ 18,026 $ 19,388 Work-in-process 1,900 1,692 Finished goods — — Inventory - current 19,926 21,080 Raw materials - long term (net of allowances of $221 and $24, respectively) 1,065 1,068 Inventory - total $ 20,991 $ 22,148 Our long-term inventory consists of raw materials that remain viable but which the Company does not expect to sell within the next year. Inventory Allowance Given its concerns about the industry backdrop, Company management determined during 2019 that an increase of its inventory allowance was necessary. Due to the slow moving nature or obsolescence of a portion of its long-term inventory and inventory related to the retirement of rental equipment, management recorded a charge of $3.8 million to write off inventory that will not be recoverable in the future. For the year ended December 31, 2020, inventory allowance totaled $0.3 million. We ended 2020 with an inventory allowance balance of $221,000. A summary of our inventory allowance is as follows: Year Ended December 31, 2020 2019 (in thousands) Beginning balance $ (24) $ (19) Accruals (251) (3,758) Write-offs 54 3,753 Ending balance (221) (24)

Rental Equipment, Property and

Rental Equipment, Property and Equipment	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Rental Equipment, Property and Equipment	Rental Equipment, Property and Equipment Rental Equipment Our rental equipment and associated accumulated depreciation as of December 31, 2020 and 2019, respectively, consisted of the following: December 31, 2020 2019 (in thousands) Compressor units $ 379,623 $ 370,961 Work-in-progress 3,764 9,129 Rental equipment 383,387 380,090 Accumulated depreciation (175,802) (162,348) Rental equipment, net of accumulated depreciation $ 207,585 $ 217,742 Our rental equipment has an estimated useful life between 15 and 25 years. Depreciation expense for rental equipment was $22.7 million and $21.4 million for the year ended December 31, 2020 and 2019, respectively. Retirement of Rental Equipment Company management routinely reviews its inventory of rental equipment for retirement or obsolescence. During 2020, management reviewed the rental fleet to determine which units were not of the type, configuration, make or model that our customers are demanding or that were not cost efficient to refurbish, maintain and/or operate. As a result of this review, we determined 216 units should be retired from our rental fleet. Accordingly, we recorded a $0.3 million loss on retirement of rental equipment during the year ended December 31, 2020. During our review of our rental compressor units in 2019, we determined 327 units should be retired from our rental fleet. We recorded a $1.5 million loss on retirement of rental equipment. Property and Equipment Property and equipment consists of the following at December 31, 2020 and 2019: December 31, Useful Lives (Years) 2020 2019 ($ in thousands) Land — $ 1,680 $ 1,290 Building 39 18,977 18,632 Building and leasehold improvements 39 1,168 1,168 Office equipment and furniture 5 2,016 2,001 Software 5 573 573 Machinery and equipment 7 3,653 3,492 Vehicles 3 7,598 7,560 Total 35,665 34,716 Less accumulated depreciation (13,916) (12,847) Total $ 21,749 $ 21,869 Depreciation expense for property and equipment was $2.3 million and $1.7 million for the year ended December 31, 2020 and 2019, respectively. Depreciation Expense by Product Line The following table depicts annual depreciation expense associated with each product line as well as our corporate activities at December 31, 2020 and 2019: December 31, 2020 2019 (in thousands) Rentals $ 24,255 $ 22,596 Sales 281 275 Service & Maintenance 42 37 Corporate 495 235 Total $ 25,073 $ 23,143

Rental Activity

Rental Activity	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Rental Activity	Rental ActivityWe rent natural gas compressor packages to entities in the petroleum industry. These rental arrangements are classified as operating leases and generally have original terms of six months to sixty months and continue on a month-to-month basis thereafter. Future minimum rent payments for arrangements not on a month-to-month basis at December 31, 2020 are as follows: Years Ending December 31, (in thousands) 2021 $ 21,565 2022 15,084 2023 13,763 2024 8,590 2025 5,845 Thereafter 13,880 Total $ 78,727

Leases

Leases	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Leases	Leases The Company determines if an arrangement is a lease at inception by assessing whether it conveys the right to control the use of an identified asset for a period of time in exchange for consideration. The Company’s leases are primarily related to property leases for its field offices. The Company's leases have remaining lease terms of one The Company's lease agreements do not contain any contingent rental payments, material residual guarantees or material restrictive covenants. Right of use assets and lease liabilities are recognized at the lease commencement date based on the present value of lease payments over the lease term. As substantially all of the Company's leases do not provide an implicit rate, the Company uses its incremental borrowing rate, which is based on a fully collateralized loan over the lease term, to determine the present value of lease payments. Based on the present value of lease payments for the Company's existing leases, the Company recorded net lease assets and lease liabilities of approximately $451,000 , respectively, upon adoption. The Company had no finance leases. The new lease standard did not materially impact the Company's consolidated statements of income and had no impact on the Company's consolidated statements of cash flows. The impact of the new lease standard on the December 31, 2020 and 2019 consolidated balance sheet was as follows: Classification on Consolidated December 31, Balance Sheet 2020 2019 ($ in thousands) Operating lease assets Right of use assets-operating leases $ 483 $ 604 Current lease liabilities Current operating leases $ 198 $ 189 Noncurrent lease liabilities Long-term operating leases 285 415 Total lease liabilities $ 483 $ 604 Weighted average remaining lease term in years 1.5 2.6 Implicit Rate 3.2 % 3.1 % Operating lease costs are recognized on a straight-line basis over the lease term. Total operating lease costs for the year ended December 31, 2020 was approximately $550,000. December 31, 2020 2019 (in thousands) Cash paid for amounts included in the measurement of lease liabilities Operating lease cost (1) (2) $ 550 $ 548 (1) Lease costs are classified on the Consolidated Statements of Operations in cost of sales, cost of compressors and selling, general and administrative expenses. (2) Includes costs of $333,000 for leases with terms of 12 months or less and $217,000 for leases with terms greater than 12 months for the year ended December 31, 2020. Includes costs of $350,000 for leases with terms of 12 months or less and $198,000 for leases with terms greater than 12 months for the year ended December 31, 2019. The following table shows the future maturities of lease liabilities: Years Ending December 31, Lease Liabilities (in thousands) 2021 $ 211 2022 76 2023 38 2024 38 2025 38 Thereafter 130 Total lease payments 531 Less: Imputed interest (48) Total $ 483 Rent expense under such leases was $217,000 and $198,000 for the years ended December 31, 2020 and 2019, respectively.

Goodwill

Goodwill	12 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	GoodwillGoodwill represents the cost in excess of fair value of the identifiable net assets acquired. Goodwill is tested annually for impairment or as needed upon the occurrence of certain events or substantive changes in circumstances that indicate goodwill is more likely than not impaired. During the third quarter of 2019, the Company examined various qualitative factors to determine if a quantitative goodwill impairment test was needed. For several months prior to the end of the third quarter of 2019, the Company experienced a significant decline in stock price, which was reflective of the significant deterioration of stock prices of companies throughout the oilfield services sector. In addition, the Company noted its largest customer as well as several other exploration and production companies had announced significant reductions to their 2020 capital expenditures budgets compared to those in 2019. These reductions clearly indicated lower demand for oilfield services, including compression services, in 2020 compared to 2019. In addition, the reductions reflected the deteriorated equity markets for energy companies and demands from institutional investors that energy companies keep capital spending within operating cash flow. After considering these factors and various other industry, economic and company-specific factors, we calculated our market capitalization (based on our closing stock price) as of September 30, 2019, and compared it to the carrying value of our net assets. Since the carrying value of our net assets exceeded our market capitalization and after considering all of the aforementioned qualitative factors, Company management determined that it was more likely than not that the fair value of the Company’s net assets was less than its carrying amount.As a result of our qualitative assessment, we proceeded to perform our quantitative goodwill impairment analysis, where we used an independent valuation specialist to assist us in determining the fair value of our net assets. In this impairment analysis, the estimated fair value of our net assets was determined utilizing market and income-based approaches. Determining fair value in this analysis required significant judgment, including judgments about appropriate comparable companies, appropriate discount rates and our estimated future cash flows, which are subject to change. As a result of our quantitative evaluation, we recorded a goodwill impairment charge of $10.0 million in 2019 eliminating our goodwill balance at that date.

Intangibles

Intangibles	12 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Intangibles	Intangibles At December 31, 2020 and 2019, the Company had intangible assets, which relate to developed technology and a trade name. The carrying amount net of accumulated amortization at December 31, 2020 and 2019 was $1.2 million and $1.3 million, respectively. Amortization expense recognized in each of the years ending December 31, 2020 and 2019 was $125,000. Estimated amortization expense for the years 2021-2024 is $125,000 per year. The Company has an intangible asset with a gross carrying value of $654,000 at December 31, 2020 related to the trade name of SCS which was acquired in our acquisition of Screw Compression Systems in January 2005. This asset is not being amortized as it has been deemed to have an indefinite life. The following table represents the identified intangible assets by major asset class (in thousands): December 31, 2020 December 31, 2019 Useful Life (years) Gross Carrying Value Accumulated Amortization Net Book Value Gross Carrying Value Accumulated Amortization Net Book Value Developed Technology 20 $ 2,505 $ 2,008 $ 497 $ 2,505 $ 1,883 $ 622 Trade Name Indefinite 654 — 654 654 — 654 Total $ 3,159 $ 2,008 $ 1,151 $ 3,159 $ 1,883 $ 1,276 Our policy is to review intangibles that are being amortized for impairment when indicators of impairment are present. In addition, it is our policy to review indefinite-lived intangible assets for impairment annually or when indicators of impairment are present. We review intangibles through an assessment of the estimated future cash flows related to such assets. In the event that assets are found to be carried at amounts in excess of estimated undiscounted future cash flows, then the assets will be adjusted for impairment to a level commensurate with a discounted cash flow analysis of the underlying assets. Based upon our analysis, we experienced no impairment of intangible assets (excluding goodwill) during the years ended December 31, 2020 or 2019.

Credit Facility

Credit Facility	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
Credit Facility	Credit Facility We had a senior secured revolving credit agreement with JP Morgan Chase Bank, N.A (the "Amended Credit Agreement") that matured on March 31, 2021. Please see Note 18 - Subsequent Events for further discussion of the maturity event. The Amended Credit Agreement had an aggregate commitment of $30 million, subject to collateral availability. We also had a right to request from the Lender, on an uncommitted basis, an increase of up to $20 million on the aggregate commitment (which could have potentially increased the commitment amount to $50 million). Borrowing Base . At any time before the maturity of the Amended Credit Agreement, we could draw, repay and re-borrow amounts available under the borrowing base up to the maximum aggregate availability discussed above. Generally, the borrowing base equaled the sum of (a) 80% of our eligible accounts receivable plus (b) 50% of the book value of our eligible general inventory (not to exceed 50% of the commitment amount at the time) plus (c) 75% of the book value of our eligible equipment inventory. JPMorgan Chase Bank (the “Lender”) could adjust the borrowing base components if material deviations in the collateral were discovered in audits of the collateral. We had $29.5 million borrowing base availability at December 31, 2020 under the terms of our Amended Credit Agreement. Interest and Fees . Under the terms of the Amended Credit Agreement, we had the option of selecting the applicable variable rate for each revolving loan, or portion thereof, of either (a) LIBOR multiplied by the Statutory Reserve Rate (as defined in the Amended Credit Agreement), with respect to this rate, for Eurocurrency funding, plus the Applicable Margin (“LIBOR-based”), or (b) CB Floating Rate, which is the Lender's Prime Rate less the Applicable Margin; provided, however, that no more than three LIBOR-based borrowings under the agreement could be outstanding at any one time. For purposes of the LIBOR-based interest rate, the Applicable Margin is 1.50%. For purposes of the CB Floating Rate, the Applicable Margin is 1.25%. Accrued interest was payable monthly on outstanding principal amounts, provided that accrued interest on LIBOR-based loans was payable at the end of each interest period, but in no event less frequently than quarterly. In addition, fees and expenses were payable in connection with our requests for letters of credit (generally equal to the Applicable Margin for LIBOR-related borrowings multiplied by the face amount of the requested letter of credit) and administrative and legal costs. Maturity . The maturity date of the Amended Credit Agreement, originally scheduled for December 31, 2020, was extended to March 31, 2021 on December 29, 2020, at which time all amounts borrowed under the agreement will be due and outstanding letters of credit must be cash collateralized. The agreement could be terminated early upon our request or the occurrence of an event of default. Security . The obligations under the Amended Credit Agreement were secured by a first priority lien on all of our inventory and accounts and lease receivables, along with a first priority lien on a variable number of our leased compressor equipment the book value of must be maintained at a minimum of 2.00 to 1.00 commitment coverage ratio (such ratio being equal to (i) the amount of the borrowing base as of such date to (ii) the amount of the commitment as of such date.) Covenants. The Amended Credit Agreement contained customary representations and warranties, as well as covenants which, among other things, limited 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 also had certain financial covenants that required us to maintain a leverage ratio less than or equal to 2.50 to 1.00 as of the last day of each fiscal quarter. Events of Default and Acceleration. The Amended Credit Agreement contained customary events of default for credit facilities of this size and type, and included, without limitation, payment defaults; defaults in performance of covenants or other agreements contained in the loan 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 $50,000; certain bankruptcy or insolvency events; the rendering of certain judgments in excess of $150,000; certain ERISA events; certain change in control events and the defectiveness of any liens under the secured revolving credit facility. Obligations under the Amended Credit Agreement could be accelerated upon the occurrence of an event of default. As of December 31, 2020, we were in compliance with all covenants in our Amended Credit Agreement. A default under our Credit Agreement would trigger the acceleration of our bank debt so that it is immediately due and payable. Such default would likely limit our ability to access other credit. At December 31, 2020 our balance on the line of credit was $417,000. Our weighted average interest rate for the year ended December 31, 2020 was 2.75%. On April 10, 2020, the Company entered into a promissory note (the "Loan") for an unsecured loan in the amount of $4.6 million through the Paycheck Protection Program ("PPP") established by the CARES Act and administered by the U.S. Small Business Administration ("SBA"). The Loan was made for the purpose of securing funding for salaries and wages of employees that may have otherwise been displaced by the outbreak of COVID-19 and the resulting detrimental impact on the Company's business. JPMorgan Chase Bank, N.A. (the "Lender") processed and funded the Loan. On April 23, 2020, the SBA advised that companies that applied for and received PPP loans that had other sufficient sources of liquidity that would not be "significantly detrimental" to their businesses may be subject to increased scrutiny and potential liability unless these companies repaid their loans in full by May 7, 2020. While the Company believes it was justified in seeking the Loan and the funds received were earmarked for the purposes set forth in the original PPP regulations, the Company voluntarily repaid the Loan, with accrued interest, to the Lender on May 4, 2020.

CARES Act Loan

CARES Act Loan	12 Months Ended
	Dec. 31, 2020
Debt Disclosure [Abstract]
CARES Act Loan	Credit Facility We had a senior secured revolving credit agreement with JP Morgan Chase Bank, N.A (the "Amended Credit Agreement") that matured on March 31, 2021. Please see Note 18 - Subsequent Events for further discussion of the maturity event. The Amended Credit Agreement had an aggregate commitment of $30 million, subject to collateral availability. We also had a right to request from the Lender, on an uncommitted basis, an increase of up to $20 million on the aggregate commitment (which could have potentially increased the commitment amount to $50 million). Borrowing Base . At any time before the maturity of the Amended Credit Agreement, we could draw, repay and re-borrow amounts available under the borrowing base up to the maximum aggregate availability discussed above. Generally, the borrowing base equaled the sum of (a) 80% of our eligible accounts receivable plus (b) 50% of the book value of our eligible general inventory (not to exceed 50% of the commitment amount at the time) plus (c) 75% of the book value of our eligible equipment inventory. JPMorgan Chase Bank (the “Lender”) could adjust the borrowing base components if material deviations in the collateral were discovered in audits of the collateral. We had $29.5 million borrowing base availability at December 31, 2020 under the terms of our Amended Credit Agreement. Interest and Fees . Under the terms of the Amended Credit Agreement, we had the option of selecting the applicable variable rate for each revolving loan, or portion thereof, of either (a) LIBOR multiplied by the Statutory Reserve Rate (as defined in the Amended Credit Agreement), with respect to this rate, for Eurocurrency funding, plus the Applicable Margin (“LIBOR-based”), or (b) CB Floating Rate, which is the Lender's Prime Rate less the Applicable Margin; provided, however, that no more than three LIBOR-based borrowings under the agreement could be outstanding at any one time. For purposes of the LIBOR-based interest rate, the Applicable Margin is 1.50%. For purposes of the CB Floating Rate, the Applicable Margin is 1.25%. Accrued interest was payable monthly on outstanding principal amounts, provided that accrued interest on LIBOR-based loans was payable at the end of each interest period, but in no event less frequently than quarterly. In addition, fees and expenses were payable in connection with our requests for letters of credit (generally equal to the Applicable Margin for LIBOR-related borrowings multiplied by the face amount of the requested letter of credit) and administrative and legal costs. Maturity . The maturity date of the Amended Credit Agreement, originally scheduled for December 31, 2020, was extended to March 31, 2021 on December 29, 2020, at which time all amounts borrowed under the agreement will be due and outstanding letters of credit must be cash collateralized. The agreement could be terminated early upon our request or the occurrence of an event of default. Security . The obligations under the Amended Credit Agreement were secured by a first priority lien on all of our inventory and accounts and lease receivables, along with a first priority lien on a variable number of our leased compressor equipment the book value of must be maintained at a minimum of 2.00 to 1.00 commitment coverage ratio (such ratio being equal to (i) the amount of the borrowing base as of such date to (ii) the amount of the commitment as of such date.) Covenants. The Amended Credit Agreement contained customary representations and warranties, as well as covenants which, among other things, limited 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 also had certain financial covenants that required us to maintain a leverage ratio less than or equal to 2.50 to 1.00 as of the last day of each fiscal quarter. Events of Default and Acceleration. The Amended Credit Agreement contained customary events of default for credit facilities of this size and type, and included, without limitation, payment defaults; defaults in performance of covenants or other agreements contained in the loan 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 $50,000; certain bankruptcy or insolvency events; the rendering of certain judgments in excess of $150,000; certain ERISA events; certain change in control events and the defectiveness of any liens under the secured revolving credit facility. Obligations under the Amended Credit Agreement could be accelerated upon the occurrence of an event of default. As of December 31, 2020, we were in compliance with all covenants in our Amended Credit Agreement. A default under our Credit Agreement would trigger the acceleration of our bank debt so that it is immediately due and payable. Such default would likely limit our ability to access other credit. At December 31, 2020 our balance on the line of credit was $417,000. Our weighted average interest rate for the year ended December 31, 2020 was 2.75%. On April 10, 2020, the Company entered into a promissory note (the "Loan") for an unsecured loan in the amount of $4.6 million through the Paycheck Protection Program ("PPP") established by the CARES Act and administered by the U.S. Small Business Administration ("SBA"). The Loan was made for the purpose of securing funding for salaries and wages of employees that may have otherwise been displaced by the outbreak of COVID-19 and the resulting detrimental impact on the Company's business. JPMorgan Chase Bank, N.A. (the "Lender") processed and funded the Loan. On April 23, 2020, the SBA advised that companies that applied for and received PPP loans that had other sufficient sources of liquidity that would not be "significantly detrimental" to their businesses may be subject to increased scrutiny and potential liability unless these companies repaid their loans in full by May 7, 2020. While the Company believes it was justified in seeking the Loan and the funds received were earmarked for the purposes set forth in the original PPP regulations, the Company voluntarily repaid the Loan, with accrued interest, to the Lender on May 4, 2020.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	Income TaxesThe (provision for) benefit from income taxes for the years ended December 31, 2020 and 2019, consists of the following (in thousands): 2020 2019 Current benefit (provision): Federal benefit (expense) $ 15,587 $ 86 State (expense) benefit (149) (55) Total current benefit (provision) 15,438 31 Deferred benefit (provision): Federal benefit (expense) (10,234) 662 State (412) — Total deferred benefit (expense) (10,646) 662 Total benefit (provision) $ 4,792 $ 693 The effective tax rate for the years ended December 31, 2020 and 2019, differs from the statutory rate as follows: 2020 2019 Statutory rate 21.0 % 21.0 % State and local taxes (17.0) % (3.7) % Uncertain tax position — % — % Goodwill impairment — % (13.7) % Research and development credit — % 1.4 % Stock based compensation (13.1) % (0.8) % Nondeductible compensation (11.6) % (0.3) % Effect of CARES Act 180.3 % — % Other 0.5 % 0.9 % Effective rate 160.1 % 4.8 % Deferred re-measurement for rate change — % — % Effective rate 160.1 % 4.8 % On 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, among other things, permits federal income tax net operating loss ("NOL") carryovers and carrybacks to offset 100% of taxable income for taxable years beginning before 2021. In addition, the CARES Act allows 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 filed carryback claims for these losses to the preceding five years. Accordingly, as of March 31, 2020, the Company recorded a federal income tax receivable of $15.0 million and an increase to its deferred tax liability of $10.1 million on its condensed balance sheet. During the third quarter of 2020, the Company received refunds corresponding to the 2018 NOL carryback, leaving a balance in the federal income tax receivable of $11.5 million at December 31, 2020. The income tax effects of temporary differences that give rise to significant portions of deferred income tax assets and (liabilities) as of December 31, 2020 and 2019, are as follows (in thousands): 2020 2019 Deferred income tax assets: Net operating loss $ 3,361 $ 1,519 Research and development credits 1,363 161 Stock compensation 175 580 Deferred compensation 705 389 Other 398 160 Total deferred income tax assets 6,002 2,809 Deferred income tax liabilities: Property and equipment (47,626) (33,761) Goodwill and other intangible assets (266) (291) Total deferred income tax liabilities (47,892) (34,052) Net deferred income tax liabilities $ (41,890) $ (31,243) As of December 31, 2020, the Company had NOL carryforwards for federal income tax purposes of $11.6 million, which may be carried forward indefinitely and can offset up to 80% of future taxable income in any given year. Future changes in ownership, as defined by Section 382 of the Internal Revenue Code, could limit the amount of NOL carryforwards used in any one year. In general, under Section 382 and 383 of the IRC, a corporation that undergoes an “ownership change” is subject to limitations on its ability to utilize its pre-change NOLs and certain tax credits, to offset future taxable income and tax. In general, an ownership change occurs if the aggregate stock ownership of certain stockholders changes by more than 50 percentage points over such stockholders’ lowest percentage of ownership during the testing period (generally three years). We account for uncertain tax positions in accordance with guidance in FASB 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 financial statements. The Company assessed whether it had any uncertain tax positions related to open tax years and concluded there were none. Accordingly, no reserve for uncertain tax positions has been recorded as of December 31, 2020 and 2019. Our policy regarding income tax interest and penalties is to expense those items as incurred. During the years ended December 31, 2020 and 2019, there were no significant income tax interest or penalty items in the statement of income.

Deferred Compensation Plans

Deferred Compensation Plans	12 Months Ended
	Dec. 31, 2020
Compensation Related Costs [Abstract]
Deferred Compensation Plans	Deferred Compensation Plans Effective January 1, 2016, the Company established a non-qualified deferred compensation plan for executive officers, directors and certain eligible employees. The assets of the deferred compensation plan are held in a rabbi trust and are subject to additional risk of loss in the event of bankruptcy or insolvency of the Company. The plan allows for deferral up to 90% of a participant’s base salary, bonus, commissions, director fees and restricted stock awards. A Company owned life insurance policy held in a rabbi trust is utilized as a source of funding for the plan. The cash surrender value of the life insurance policy is $2.0 million and $1.5 million as of December 31, 2020 and 2019, respectively, with a gain related to the policy of $168,000 and $218,800 reported in other income in our consolidated income statement for the year ended December 31, 2020 and 2019, respectively. For deferrals of base salary, bonus, commissions and director fees, settlement payments are made to participants in cash, either in a lump sum or in periodic installments. The deferred obligation to pay the deferred compensation and the deferred director fees is adjusted to reflect the positive or negative performance of investment measurement options selected by each participant and was $2.2 million and $1.7 million as of December 31, 2020 and 2019, respectively. The deferred obligation is included in other long-term liabilities in the consolidated balance sheet.

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2020
Stockholders' Equity Attributable to Parent [Abstract]
Stockholders' Equity	Stockholders' Equity Preferred Stock We have a total of 5.0 million authorized preferred shares with rights and preferences as designated by the Board of Directors. As of December 31, 2020 and 2019, there were no issued or outstanding preferred shares.

Stock-Based and Other Long-Term

Stock-Based and Other Long-Term Incentive Compensation	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Stock-Based and Other Long-Term Incentive Compensation	Stock-Based and Other Long-Term Incentive Compensation Restricted Stock/Units On June 18, 2014, at our annual meeting of shareholders, our shareholders approved a proposed amendment to the 2009 Restricted Stock/Unit Plan (the "2009 Plan") to add additional 500,000 shares of common stock to the Plan, thereby authorizing the issuance of up to 800,000 shares of common stock under the Plan. The 2009 Plan expired on June 16, 2019. At December 31, 2020 we had 34,899 shares outstanding under the 2009 Plan that will vest over the next one year. On June 20, 2019, at our annual meeting of shareholders, our shareholders approved a new proposed Equity Incentive Plan for restricted shares/units and stock options. The Equity Incentive Plan allows issuance up to 500,000 share of common stock. As of December 31, 2020, we had 223,202 shares outstanding under the Equity Incentive Plan that will vest over the next three years. In accordance with the Company's employment agreement with Stephen Taylor, the Company's Chief Executive Officer, the Compensation Committee reviewed his performance in determining the issuance of restricted common stock. Based on this review which included consideration of the Company's 2019 performance, Mr. Taylor, was awarded 94,133 restricted shares/units on April 28, 2020, which vest over three years, in equal installments beginning April 28, 2021. On April 28, 2020, the Compensation Committee awarded 10,000 restricted shares/units to James Hazlett, our Vice President of Technical Services. The restricted shares/units to Mr. Hazlett vest over three years, in equal installments, beginning April 28, 2021. We also awarded and issued 4,432 shares of restricted common stock/units to each of our four independent Board members as partial payment for 2020 directors' fees. The restricted stock/units issued to our directors vests in one year from the date of grant. Compensation expense related to the restricted shares/units was approximately $2.2 million and $2.5 million for the years ended December 31, 2020 and 2019, respectively. As of December 31, 2020, there was a total of approximately $1.8 million of unrecognized compensation expense related to the unvested portion of these restricted shares/units. This expense is expected to be recognized over the next three years. As of December 31, 2020, 200,141 shares were still available for issuance under the Equity Incentive Plan. A summary of all restricted stock/units activity as of December 31, 2019 and 2020 and changes during the years then ended are presented below. Number Weighted Average Weighted Aggregate Intrinsic Value (in thousands) Outstanding, December 31, 2018 214,630 $ 25.51 8.85 $ 3,529 Granted 199,810 17.16 — 3,433 Vested (134,674) 24.26 — 2,807 Canceled/Forfeited — — — — Outstanding, December 31, 2019 279,766 $ 20.15 8.77 $ 3,430 Granted 123,185 5.68 — 700 Vested (144,850) 20.82 — 946 Canceled/Forfeited — — — — Outstanding, December 31, 2020 258,101 $ 12.87 8.61 $ 2,447 Other Long-Term Incentive Compensation On April 28, 2020, based on its review of Mr. Taylor's 2019 performance, the Compensation Committee also issued a long-term incentive award of $1.1 million to Mr. Taylor that vests in equal, annual tranches over three years. At the time of vesting, each tranche will be payable in cash or common stock at the discretion of the Compensation Committee. In addition, on April 28, 2020, we issued a $50,000 award to each of our four independent members of our Board of Directors as partial payment for their services in 2020. These awards vest one year from the date of grant and are payable in cash upon vesting. The Company accounts for these other long-term incentive awards to Mr. Taylor and our independent Board members as liabilities under accrued liabilities on our condensed consolidated balance sheet. The vesting of these 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). Total compensation expense related to these other long-term incentive awards was approximately $0.4 million for the year ended December 31, 2020. As of December 31, 2020 there was a total of $0.8 million of unrecognized compensation expense related to these other long-term incentive awards which is expected to be recognized over the next 2.25 years. Stock Option Plan Our Stock Option Plan which is stockholder approved, permits the granting of stock options to its employees for up to 1.0 million shares of common stock under the Stock Option Plan. We believe that such awards align the interests of our employees with our stockholders. Option awards are generally granted with an exercise price equal to the market price of our stock at the date of grant; those option awards generally vest based on three years of continuous service and have ten-year contractual terms. Certain option and share awards provide for accelerated vesting if there is a change in control of the Company (as defined in the Stock Option Plan). The last date that grants can be made under the Stock Option Plan is February 28, 2026. As of December 31, 2020, 384,503 shares were still available for issue under the Stock Option Plan. The fair value of each option award is estimated on the date of grant using the Black-Scholes option valuation model that uses the assumptions noted in the following table. The risk-free rate for periods within the contractual life of the option is based on the U.S. Treasury yield curve in effect at the time of grant. The expected life of options granted is based on the vesting period and historical exercise and post-vesting employment termination behavior for similar grants. We use historical data to estimate option exercise and employee termination within the valuation model; separate groups of employees that have similar historical exercise behavior are considered separately for valuation purposes. Weighted average Black -Scholes fair value assumption during the year ended December 31, are as follows: 2020 Risk free rate 0.48 % Expected life 6.59 Expected volatility 42.33 % Expected dividend yield — % There were no stock option grants made in 2019. A summary of all option activity as of December 31, 2019 and 2020 and changes during the years then ended are presented below: Number Weighted Average Weighted Aggregate Intrinsic Value (in thousands) Outstanding, December 31, 2018 283,686 $ 20.46 3.58 $ 434 Granted — — — — Exercised (56,352) 8.97 — 474 Canceled/Forfeited (8,000) 21.60 — — Expired (11,000) 17.74 — — Outstanding, December 31, 2019 208,334 $ 23.67 3.66 $ — Granted 5,000 4.91 — — Exercised — — — — Canceled/Forfeited (12,000) 20.20 — 23,750 Expired (40,000) 19.11 — — Outstanding, December 31, 2020 161,334 $ 24.48 3.48 $ — Exercisable, December 31, 2020 161,334 $ 24.48 3.48 $ — The weighted average grant date fair value of options granted during 2020 was $2.07. We had no grants in 2019. The total intrinsic value, or the difference between the exercise price and the market price on the date of exercise, of options exercised during the years ended December 31, 2019 was approximately $474,000. There were no option exercises in 2020. Cash received from stock options exercised during the years ended December 31, 2019 was approximately $506,000. The following table summarizes information about our stock options outstanding at December 31, 2020: 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 24,500 0.41 $ 16.80 24,500 $ 16.80 $18.01-22.00 20,500 2.22 18.75 20,500 18.75 $22.01-26.00 42,167 4.28 22.90 42,167 22.90 $26.01-30.00 30,000 6.13 28.15 30,000 28.15 $30.01-34.00 44,167 3.22 30.41 44,167 30.41 161,334 3.48 $ 24.48 161,334 $ 24.48 The summary of the status of our unvested stock options as of December 31, 2020 and changes during the year then ended is presented below. Unvested stock options: Shares Weighted Average Grant Date Fair Value Unvested at December 31, 2019 10,433 $ 11.93 Granted 5,000 2.07 Vested (10,433) 11.93 Canceled/Forfeited (5,000) 2.07 Unvested at December 31, 2020 — $ — We recognized stock compensation expense from stock options vesting of $19,366 and $124,000 for the years ended December 31, 2020 and 2019, respectively. As of December 31, 2020, there was no unamortized compensation cost related to unvested stock options.

(Loss) Earnings per Share

(Loss) Earnings per Share	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
(Loss) Earnings per Share	(Loss) Earnings per Share Basic (loss) earnings per common share is computed using the weighted average number of common shares outstanding during the period. Diluted (loss) earnings per common share is computed using the weighted average number of common stock and common stock equivalent shares outstanding during the period. The following table sets forth the computation of basic and diluted (loss) earnings per share (in thousands, except per share amounts): Year Ended December 31, 2020 2019 Numerator: Net (loss) income $ 1,808 $ (13,864) Denominator for basic net (loss) income per common share: Weighted average common shares outstanding 13,224 13,114 Denominator for diluted net (loss) income per share: Weighted average common shares outstanding 13,224 13,114 Dilutive effect of stock options and restricted shares 37 — Diluted weighted average shares 13,261 13,114 (Loss) earnings per common share: Basic $ 0.14 $ (1.06) Diluted $ 0.14 $ (1.06) In the year ended ended December 31, 2020, 221,061 restricted stock/units and 161,334 stock options were not included in the computation of dilutive income per share, due to their anti-dilutive effect. In the year ended ended December 31, 2019, 279,766 restricted stock/units and 208,334 stock options were not included in the computation of diluted loss per share due to their antidilutive effect.

Related Party

Related Party	12 Months Ended
	Dec. 31, 2020
Related Party Transactions [Abstract]
Related Party	Related Party In 2016, we entered into a joint venture partnership, N-G, LLC (‘N-G”), with Genis Holdings, LLC (“Genis”) to explore new technologies for wellhead compression. NGS and Genis both share 50% ownership of N-G. We account for this investment under the equity method. In 2018, we ordered some compressor packages from Genis, totaling $1.0 million. The compressors were completed and paid in full at December 31, 2019.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Legal Proceedings From time to time, we are a party to various legal proceedings in the ordinary course of our business. While management is unable to predict the ultimate outcome of these actions, it believes that any ultimate liability arising from these actions will not have a material effect on our financial position, results of operations or cash flow. We are not currently a party to any bankruptcy, receivership, reorganization, adjustment or similar proceeding, and we are not aware of any other threatened litigation.

Subsequent Events

Subsequent Events	12 Months Ended
	Dec. 31, 2020
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events On March 31, 2021 our Amended Credit Agreement expired and we have decided not to renew the Amended Credit Agreement. On March 17, 2021 all outstanding indebtedness was repaid. We are in the process of negotiating a new credit facility which we expect to complete by the end of April 2021, although no guarantee can be made that we will be successful in finalizing and securing a new credit facility.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Principles of Consolidation	Principles of ConsolidationThe accompanying 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, see Note 12. All significant intercompany accounts and transactions for the periods presented have been eliminated in consolidation.
Use of Estimates	Use of Estimates The preparation of our consolidated financial statements in conformity with generally accepted accounting principles in the United States of America requires our management to make estimates and assumptions that affect the amounts reported in these consolidated financial statements and accompanying notes. Actual results could differ from those estimates. Significant estimates include fixed asset lives, bad debt allowance and the allowance for inventory obsolescence. Additionally, NGS conducts a yearly review of impairment of long-lived assets. Throughout the review, determining factors are based on estimates that can significantly impact the carrying value of these assets. It is at least reasonably possible these estimates could be revised in the near term and the revisions could be material.
Cash Equivalents and Financial Instruments	Cash Equivalents and Financial InstrumentsFor purposes of reporting cash flows, we consider all short-term investments with an original maturity of three months or less to be cash equivalents. We invest our cash primarily in deposits and money market funds with commercial banks.  At times, cash balances at banks and financial institutions may exceed federally insured amounts. We believe that the risk to our cash balance is minimal because we have chosen a large bank with strong long-term ratings of Aa2/A+.
Accounts Receivable	Accounts ReceivableOur trade receivables consist of customer obligations for the sale of compressors and flare systems due under normal trade terms, and operating leases for the use of our natural gas compressors.  The receivables are not collateralized except as provided for under lease agreements.  However, we typically require deposits of as much as 50% or use of progress payments for large custom sales contracts.  We perform ongoing credit evaluations of our customers and adjust credit limits based on management's assessment of the customer's financial condition and payment history, as well as industry conditions and general economic conditions.  We continuously monitor collections and payments from our customers, and maintain a provision for estimated credit losses based upon our historical experience and any specific customer collection issues that we have identified.  While such credit losses have historically been within our expectations and the provisions established, we cannot guarantee that we will continue to experience the same credit loss rates that we have in the past.  One customer accounted for 35% of our accounts receivable as of December 31, 2020 and 2019.  A significant change in the liquidity or financial position of this customer could have a material adverse impact on the collectability of our accounts receivable and our future operating results.
Revenue Recognition Policy	Revenue Recognition Policy 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 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 compressors and flare 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 or flare during the rental contract. Our rental contracts typically range from six Sales Revenue. The Company generates revenue by the sale of custom/fabricated compressors, flare systems and parts, as well as, exchange/rebuilding customer owned compressors and sale of used rental equipment. Custom/fabricated compressors and flare systems - The Company designs and fabricates compressors and flares 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 or flare package is completed and shipped, or in accordance with a bill and hold arrangements 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 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, upon the customer’s written request, 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 we ship the equipment per their direction from our manufacturing facility at a later specified date and that we segregate the equipment from our finished goods, such that they are 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 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 shouldered by the customer and there are no exceptions to the customer’s commitment to accept and pay for the manufactured equipment. Revenues recognized related to bill and hold arrangements for the years ended December 31, 2020 and 2019 was approximately $0.9 million and $11.6 million, respectively. 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 or flares - From time to time, a customer may request to purchase a used compressor or flare 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. Service and Maintenance Revenue. The Company provides routine or call-out services on customer owned equipment. Revenue is recognized after services in the contract are rendered. Payment terms for sales revenue and service and maintenance revenue discussed above are generally 30 to 60 days although terms for specific customers can vary. Also, the 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 expense on our Consolidated Statements of Operations.
Leases	Leases On January 1, 2019, we adopted ASC 842 using the modified retrospective method. We recognized the cumulative effect of initially applying the new lease standard and had no adjustments to retained earnings. The comparative information has not been restated and continues to be reported under the lease accounting standard in effect for those periods. The new lease standard requires all leases to be reported on the balance sheet as right-of-use assets and lease obligations. We elected the practical expedients permitted under the transition guidance of the new standard that retained the lease classification and initial direct costs for any leases that existed prior to adoption of the standard. We did not reassess whether any contracts or land easements entered into prior to adoption are leases or contain leases.
Major Customers and Concentration of Credit Risk	Major Customers and Concentration of Credit RiskSales and rental income from Occidental Permian, LTD. ("Oxy") in 2020 and 2019 amounted to 30% and 36% of revenue, respectively. No other single customer accounted for more than 10% of our revenues in 2020 and 2019. Oxy's accounts receivable balances amounted to 35% and 35% of our accounts receivable as of December 31, 2020 and 2019, respectively. No other customers amounted to more than 10% of our accounts receivable as of December 31, 2020 and 2019.
Inventory	InventoryInventory (current and long-term) is valued at the lower of cost and net realizable value.  The cost of inventories is determined by the weighted average method. We regularly review inventory quantities on hand and record a provision for excess and obsolete inventory based primarily on current and anticipated customer demand and production requirements. The Company assesses anticipated customer demand based on current and upcoming capital expenditure budgets of its major customers as well as other significant companies in the industry, along with oil and natural gas price forecasts and other factors affecting the industry. In addition, our long-term inventory consists of raw materials that remain viable but which the Company does not expect to sell within the next year.
Rental Equipment and Property and Equipment	Rental Equipment and Property and EquipmentRental equipment and property and equipment are recorded at cost less accumulated depreciation, except for work-in-progress on new rental equipment which is recorded at cost until it’s complete and added to the fleet. Depreciation is computed using the straight-line method over the estimated useful lives of the assets. Our rental equipment has an estimated useful life between 15 and 25 years, while our property and equipment has an estimate useful lives which range from 3 to 39 years.  The majority of our property and equipment, including rental equipment, is a direct cost to generating revenue.
Impairment of Rental Equipment	We assess the impairment of rental equipment and property and equipment whenever events or changes in circumstances indicate that the net recorded amount may not be recoverable. The following factors could trigger an impairment review: significant underperformance relative to historical or projected future cash flows; significant adverse changes in the extent or manner in which asset (or asset group) is being used or its condition, including a meaningful drop in fleet utilization over the prior four quarters; significant negative industry or company-specific trends or actions, including meaningful capital expenditure budget reductions by our major customers or other sizable exploration and production or midstream companies, as well as significant declines in oil and natural gas prices; legislative changes prohibiting us from leasing our units or flares; or poor general economic conditions. An impairment loss is recognized if the future undiscounted cash flows associated with the asset (or asset group) and the estimated fair value of the asset are less than the asset's carrying value. Sales of equipment out of the rental fleet are included with sales revenue and cost of sales, while retirements of units are shown a separate operating expense. Gains and losses resulting from sales and dispositions of other property and equipment are included with other income. Maintenance and repairs are charged to cost of rentals as incurred.
Goodwill	GoodwillGoodwill represents the cost in excess of fair value of the identifiable net assets acquired. Goodwill is tested annually for impairment or as needed upon the occurrence of certain events or substantive changes in circumstances that indicate goodwill is more likely than not impaired. As further described in Note 7 of these financial statements, we fully impaired the Company's goodwill during the third quarter of 2019, resulting in a goodwill impairment charge of $10.0 million for the year ended December 31, 2019.
Intangibles	Intangibles At December 31, 2020 and 2019, NGS had intangible assets, which relate to developed technology and a trade name. Developed technology is amortized on a straight-line basis with a useful life of 20 years, with a weighted average remaining life of approximately five years as of December 31, 2020. NGS has an intangible asset related to the trade name of SCS which was acquired in our acquisition of Screw Compression Systems in January 2005. This asset is not being amortized as it has been deemed to have an indefinite life.
Warranty	WarrantyWe accrue amounts for estimated warranty claims based upon current and historical product warranty costs and any other related information known.
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 carry-forwards. 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. We assess the likelihood that our deferred tax assets will be recovered from future taxable income and, to the extent we believe that recovery is not probable, we establish a valuation allowance. To the extent we establish a valuation allowance or increase this allowance in a period, we include an expense in the tax provision in the statement of income. ASC Topic 740 prescribes a recognition threshold and measurement attribute for the financial statement recognition and measurement of a tax position taken or expected to be taken in a tax return. In order to record any financial statement benefit, we are required to determine, based on technical merits of the position, whether it is more likely than not (a likelihood of more than 50 percent) that a tax position will be sustained upon examination, including resolution of any related appeals or litigation processes. If that step is satisfied, then we must measure the tax position to determine the amount of benefit to recognize in the financial statements. The tax position is measured at the largest amount of the benefit that is greater than 50 percent likely of being realized upon ultimate settlement. Our policy regarding income tax interest and penalties is to expense those items as other expense.
Fair Value Measurement	Fair Value Measurement Fair value is defined as the price that would be received to sell an asset or paid to transfer a liability in an orderly transaction between market participants at the measurement date under current market conditions. ASC Topic 820 established a fair value hierarchy, which requires an entity to maximize the use of observable inputs when measuring fair value. These inputs are categorized as follows: Level 1- quoted prices in an active market for identical assets or liabilities; Level 2- quoted prices in an active market for similar assets or liabilities, inputs other than quoted prices that are observable for similar assets or liabilities, inputs derived principally from or corroborated by observable market data by correlation or other means; and Level 3- valuation methodology with unobservable inputs that are significant to the fair value measurement.
Segments and Related Information	Segments and Related Information ASC 280-10-50, “Operating Segments”, define the characteristics of an operating segment as a) being engaged in business activity from which it may earn revenue and incur expenses, b) being reviewed by the company's chief operating decision maker (CODM) for decisions about resources to be allocated and assess its performance and c) having discrete financial information. Although we indeed look at our products to analyze the nature of our revenue, other financial information, such as certain costs and expenses, net income and EBITDA are not captured or analyzed by these categories. Our CODM does not make resource allocation decisions or access the performance of the business based on these categories, but rather in the aggregate. Based on this, management believes that it operates in one business segment. In their analysis of product lines as potential operating segments, management also considered ASC 280-10-50-11, “Aggregation Criteria”, which allows for the aggregation of operating segments if the segments have similar economic characteristics and if the segments are similar in each of the following areas: • The nature of the products and services; • The nature of the production processes; • The type or class of customer for their products and services; • The methods used to distribute their products or provide their services; and • The nature of the regulatory environment, if applicable. We are engaged in the business of designing and manufacturing compressors and flares. Our compressors and flares are sold and rented to our customers. In addition, we provide service and maintenance on compressors in our fleet and to third parties. These business activities are similar in all geographic areas. Our manufacturing process is essentially the same for the entire Company and is performed in house at our facilities in Midland, Texas and Tulsa, Oklahoma. Our customers primarily consist of entities in the business of producing natural gas. The maintenance and service of our products is consistent across the entire Company and is performed via an internal fleet of vehicles. The regulatory environment is similar in every jurisdiction in that the most impacting regulations and practices are the result of federal energy policy. In addition, the economic characteristics of each customer arrangement are similar in that we maintain policies at the corporate level.
Recently Issued Accounting Pronouncements	Recently Issued Accounting Pronouncements In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform, which provides temporary optional guidance to companies impacted by the transition away from the London Interbank Offered Rate ("LIBOR"). The guidance provides certain expedients and exceptions to applying GAAP in order to lessen the potential accounting burden when contracts, hedging relationships and other transactions that reference LIBOR as a benchmark rate are modified. This guidance is effective upon issuance and expires on December 31, 2022. We are currently evaluating the impact of the LIBOR transition and this ASU 2020-04 on our consolidated financial statements. In December 2019, the FASB issued ASU 2019-12, Income Taxes (ASC Topic 740), which simplifies accounting for income taxes by removing certain exceptions to various tax accounting principles and clarifies other existing guidance in order to improve consistency of application. These amendments are effective for public entities for interim and annual periods beginning after December 15, 2020. We are currently evaluating the impact of ASU 2019-12 on our consolidated financial statements and note disclosures.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2020
Accounting Policies [Abstract]
Schedule of Allowance for Doubtful Accounts	A summary of our allowance for doubtful accounts is as follows: Year Ended December 31, ($ in thousands) 2020 2019 Beginning balance $ (918) $ (291) Accruals (329) (664) Recoveries — — Write-offs 86 37 Ending balance $ (1,161) $ (918)
Disaggregation of Revenue	The following table shows the Company's revenue disaggregated by product or service type for the years ended: Year Ended December 31, 2020 2019 (in thousands) Compressors - sales $ 2,211 $ 15,185 Flares - sales 489 959 Other (Parts/Rebuilds) - sales 2,957 3,619 Service and maintenance 1,572 1,980 Total revenue from contracts with customers 7,229 21,743 Add: ASC 842 rental revenue 60,826 56,701 Total revenue $ 68,055 $ 78,444
Contract with Customer, Asset and Liability	As of December 31, 2020 and 2019, we had the following receivables and deferred income from contracts with customers: December 31, 2020 2019 (in thousands) Accounts Receivable Accounts receivable - contracts with customers $ 3,243 $ 3,061 Accounts receivable - ASC 842 9,802 6,963 Total Accounts Receivable 13,045 10,024 Less: Allowance for doubtful accounts (1,161) (918) Total Accounts Receivable, net 11,884 9,106 Deferred income $ 1,103 $ 640
Cumulative Effect of Changes from Adoption of ASU	The cumulative effect of the changes made to our consolidated balance sheet at January 1, 2019, for the adoption of ASC 842 was as follows: Balance at December 31, 2018 Adjustments due to ASC 842 Balance at January 1, 2019 (in thousands) Balance Sheet Assets Right of use assets $ — $ 451 $ 451 Liabilities Current portion of operating leases $ — $ 126 $ 126 Long term portion of operating leases — 325 325 Total lease liabilities $ — $ 451 $ 451

Inventory (Tables)

Inventory (Tables)	12 Months Ended
	Dec. 31, 2020
Inventory Disclosure [Abstract]
Schedule of Inventory	Our inventory, net of allowance for obsolescence of $221,000 and $24,000 at December 31, 2020 and 2019, respectively, consisted of the following: December 31, 2020 2019 (in thousands) Raw materials - current $ 18,026 $ 19,388 Work-in-process 1,900 1,692 Finished goods — — Inventory - current 19,926 21,080 Raw materials - long term (net of allowances of $221 and $24, respectively) 1,065 1,068 Inventory - total $ 20,991 $ 22,148 A summary of our inventory allowance is as follows: Year Ended December 31, 2020 2019 (in thousands) Beginning balance $ (24) $ (19) Accruals (251) (3,758) Write-offs 54 3,753 Ending balance (221) (24)

Rental Equipment, Property an_2

Rental Equipment, Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2020
Property, Plant and Equipment [Abstract]
Schedule of Rental Equipment	Our rental equipment and associated accumulated depreciation as of December 31, 2020 and 2019, respectively, consisted of the following: December 31, 2020 2019 (in thousands) Compressor units $ 379,623 $ 370,961 Work-in-progress 3,764 9,129 Rental equipment 383,387 380,090 Accumulated depreciation (175,802) (162,348) Rental equipment, net of accumulated depreciation $ 207,585 $ 217,742 Property and equipment consists of the following at December 31, 2020 and 2019: December 31, Useful Lives (Years) 2020 2019 ($ in thousands) Land — $ 1,680 $ 1,290 Building 39 18,977 18,632 Building and leasehold improvements 39 1,168 1,168 Office equipment and furniture 5 2,016 2,001 Software 5 573 573 Machinery and equipment 7 3,653 3,492 Vehicles 3 7,598 7,560 Total 35,665 34,716 Less accumulated depreciation (13,916) (12,847) Total $ 21,749 $ 21,869 The following table depicts annual depreciation expense associated with each product line as well as our corporate activities at December 31, 2020 and 2019: December 31, 2020 2019 (in thousands) Rentals $ 24,255 $ 22,596 Sales 281 275 Service & Maintenance 42 37 Corporate 495 235 Total $ 25,073 $ 23,143

Rental Activity (Tables)

Rental Activity (Tables)	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Schedule of Future Minimum Rent Payments Receivable	Future minimum rent payments for arrangements not on a month-to-month basis at December 31, 2020 are as follows: Years Ending December 31, (in thousands) 2021 $ 21,565 2022 15,084 2023 13,763 2024 8,590 2025 5,845 Thereafter 13,880 Total $ 78,727

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2020
Leases [Abstract]
Schedule of Balance Sheet Impact	The impact of the new lease standard on the December 31, 2020 and 2019 consolidated balance sheet was as follows: Classification on Consolidated December 31, Balance Sheet 2020 2019 ($ in thousands) Operating lease assets Right of use assets-operating leases $ 483 $ 604 Current lease liabilities Current operating leases $ 198 $ 189 Noncurrent lease liabilities Long-term operating leases 285 415 Total lease liabilities $ 483 $ 604 Weighted average remaining lease term in years 1.5 2.6 Implicit Rate 3.2 % 3.1 %
Schedule of Cash Flow Impact	December 31, 2020 2019 (in thousands) Cash paid for amounts included in the measurement of lease liabilities Operating lease cost (1) (2) $ 550 $ 548 (1) Lease costs are classified on the Consolidated Statements of Operations in cost of sales, cost of compressors and selling, general and administrative expenses. (2) Includes costs of $333,000 for leases with terms of 12 months or less and $217,000 for leases with terms greater than 12 months for the year ended December 31, 2020. Includes costs of $350,000 for leases with terms of 12 months or less and $198,000 for leases with terms greater than 12 months for the year ended December 31, 2019.
Schedule of Future Maturities of Lease Liabilities	The following table shows the future maturities of lease liabilities: Years Ending December 31, Lease Liabilities (in thousands) 2021 $ 211 2022 76 2023 38 2024 38 2025 38 Thereafter 130 Total lease payments 531 Less: Imputed interest (48) Total $ 483

Intangibles (Tables)

Intangibles (Tables)	12 Months Ended
	Dec. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Identified Finite-Lived Intangible Assets, Finite Lived	The following table represents the identified intangible assets by major asset class (in thousands): December 31, 2020 December 31, 2019 Useful Life (years) Gross Carrying Value Accumulated Amortization Net Book Value Gross Carrying Value Accumulated Amortization Net Book Value Developed Technology 20 $ 2,505 $ 2,008 $ 497 $ 2,505 $ 1,883 $ 622 Trade Name Indefinite 654 — 654 654 — 654 Total $ 3,159 $ 2,008 $ 1,151 $ 3,159 $ 1,883 $ 1,276
Schedule of Identified Indefinite-Lived Intangible Assets	The following table represents the identified intangible assets by major asset class (in thousands): December 31, 2020 December 31, 2019 Useful Life (years) Gross Carrying Value Accumulated Amortization Net Book Value Gross Carrying Value Accumulated Amortization Net Book Value Developed Technology 20 $ 2,505 $ 2,008 $ 497 $ 2,505 $ 1,883 $ 622 Trade Name Indefinite 654 — 654 654 — 654 Total $ 3,159 $ 2,008 $ 1,151 $ 3,159 $ 1,883 $ 1,276

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2020
Income Tax Disclosure [Abstract]
Provision for Income Taxes	The (provision for) benefit from income taxes for the years ended December 31, 2020 and 2019, consists of the following (in thousands): 2020 2019 Current benefit (provision): Federal benefit (expense) $ 15,587 $ 86 State (expense) benefit (149) (55) Total current benefit (provision) 15,438 31 Deferred benefit (provision): Federal benefit (expense) (10,234) 662 State (412) — Total deferred benefit (expense) (10,646) 662 Total benefit (provision) $ 4,792 $ 693
Effective Income Tax Rate Reconciliation	The effective tax rate for the years ended December 31, 2020 and 2019, differs from the statutory rate as follows: 2020 2019 Statutory rate 21.0 % 21.0 % State and local taxes (17.0) % (3.7) % Uncertain tax position — % — % Goodwill impairment — % (13.7) % Research and development credit — % 1.4 % Stock based compensation (13.1) % (0.8) % Nondeductible compensation (11.6) % (0.3) % Effect of CARES Act 180.3 % — % Other 0.5 % 0.9 % Effective rate 160.1 % 4.8 % Deferred re-measurement for rate change — % — % Effective rate 160.1 % 4.8 %
Deferred Tax Assets and Liabilities	The income tax effects of temporary differences that give rise to significant portions of deferred income tax assets and (liabilities) as of December 31, 2020 and 2019, are as follows (in thousands): 2020 2019 Deferred income tax assets: Net operating loss $ 3,361 $ 1,519 Research and development credits 1,363 161 Stock compensation 175 580 Deferred compensation 705 389 Other 398 160 Total deferred income tax assets 6,002 2,809 Deferred income tax liabilities: Property and equipment (47,626) (33,761) Goodwill and other intangible assets (266) (291) Total deferred income tax liabilities (47,892) (34,052) Net deferred income tax liabilities $ (41,890) $ (31,243)

Stock-Based and Other Long-Te_2

Stock-Based and Other Long-Term Incentive Compensation (Tables)	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Summary of Restricted Stock Activity	A summary of all restricted stock/units activity as of December 31, 2019 and 2020 and changes during the years then ended are presented below. Number Weighted Average Weighted Aggregate Intrinsic Value (in thousands) Outstanding, December 31, 2018 214,630 $ 25.51 8.85 $ 3,529 Granted 199,810 17.16 — 3,433 Vested (134,674) 24.26 — 2,807 Canceled/Forfeited — — — — Outstanding, December 31, 2019 279,766 $ 20.15 8.77 $ 3,430 Granted 123,185 5.68 — 700 Vested (144,850) 20.82 — 946 Canceled/Forfeited — — — — Outstanding, December 31, 2020 258,101 $ 12.87 8.61 $ 2,447
Stock Options Fair Value Assumptions	The fair value of each option award is estimated on the date of grant using the Black-Scholes option valuation model that uses the assumptions noted in the following table. The risk-free rate for periods within the contractual life of the option is based on the U.S. Treasury yield curve in effect at the time of grant. The expected life of options granted is based on the vesting period and historical exercise and post-vesting employment termination behavior for similar grants. We use historical data to estimate option exercise and employee termination within the valuation model; separate groups of employees that have similar historical exercise behavior are considered separately for valuation purposes. Weighted average Black -Scholes fair value assumption during the year ended December 31, are as follows: 2020 Risk free rate 0.48 % Expected life 6.59 Expected volatility 42.33 % Expected dividend yield — %
Summary of Option Activity	A summary of all option activity as of December 31, 2019 and 2020 and changes during the years then ended are presented below: Number Weighted Average Weighted Aggregate Intrinsic Value (in thousands) Outstanding, December 31, 2018 283,686 $ 20.46 3.58 $ 434 Granted — — — — Exercised (56,352) 8.97 — 474 Canceled/Forfeited (8,000) 21.60 — — Expired (11,000) 17.74 — — Outstanding, December 31, 2019 208,334 $ 23.67 3.66 $ — Granted 5,000 4.91 — — Exercised — — — — Canceled/Forfeited (12,000) 20.20 — 23,750 Expired (40,000) 19.11 — — Outstanding, December 31, 2020 161,334 $ 24.48 3.48 $ — Exercisable, December 31, 2020 161,334 $ 24.48 3.48 $ —
Summary of Stock Options Outstanding	The following table summarizes information about our stock options outstanding at December 31, 2020: 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 24,500 0.41 $ 16.80 24,500 $ 16.80 $18.01-22.00 20,500 2.22 18.75 20,500 18.75 $22.01-26.00 42,167 4.28 22.90 42,167 22.90 $26.01-30.00 30,000 6.13 28.15 30,000 28.15 $30.01-34.00 44,167 3.22 30.41 44,167 30.41 161,334 3.48 $ 24.48 161,334 $ 24.48
Summary of the Status of Unvested Stock Options	The summary of the status of our unvested stock options as of December 31, 2020 and changes during the year then ended is presented below. Unvested stock options: Shares Weighted Average Grant Date Fair Value Unvested at December 31, 2019 10,433 $ 11.93 Granted 5,000 2.07 Vested (10,433) 11.93 Canceled/Forfeited (5,000) 2.07 Unvested at December 31, 2020 — $ —

(Loss) Earnings per Share (Tabl

(Loss) Earnings per Share (Tables)	12 Months Ended
	Dec. 31, 2020
Earnings Per Share [Abstract]
Computation of Basic and Diluted Earnings Per Share	The following table sets forth the computation of basic and diluted (loss) earnings per share (in thousands, except per share amounts): Year Ended December 31, 2020 2019 Numerator: Net (loss) income $ 1,808 $ (13,864) Denominator for basic net (loss) income per common share: Weighted average common shares outstanding 13,224 13,114 Denominator for diluted net (loss) income per share: Weighted average common shares outstanding 13,224 13,114 Dilutive effect of stock options and restricted shares 37 — Diluted weighted average shares 13,261 13,114 (Loss) earnings per common share: Basic $ 0.14 $ (1.06) Diluted $ 0.14 $ (1.06)

Summary of Significant Accoun_4

Summary of Significant Accounting Policies - Narrative (Details)	12 Months Ended
	Dec. 31, 2020USD ($)segment	Dec. 31, 2019USD ($)
Revenue from External Customer [Line Items]
Cash equivalents, qualification, maximum original maturity of short-term investments	3 months
Customer deposit requirements, large custom contracts, maximum percentage	50.00%
Allowance for doubtful accounts	$ 1,161,000	$ 918,000
Revenues	68,055,000	78,444,000
Revenue recognized	$ 73,000	48,000
Amortization period of capitalized contract costs	1 year
Impairment of goodwill	$ 0	10,039,000
Product warranty reserves	0	74,000
Uncertain tax positions	$ 0
Number of business segments | segment	1
Minimum
Revenue from External Customer [Line Items]
Rental contract term	6 months
Property and equipment, estimated useful life	3 years
Minimum | Rental Equipment
Revenue from External Customer [Line Items]
Property and equipment, estimated useful life	15 years
Maximum
Revenue from External Customer [Line Items]
Rental contract term	60 months
Property and equipment, estimated useful life	39 years
Maximum | Rental Equipment
Revenue from External Customer [Line Items]
Property and equipment, estimated useful life	25 years
Developed Technology
Revenue from External Customer [Line Items]
Intangible assets, useful life	20 years
Intangible assets, weighted average remaining life	5 years
Bill and Hold Arrangement
Revenue from External Customer [Line Items]
Revenues	$ 900,000	$ 11,600,000
Rental Contracts, Excluding Large Horsepower Compressors | Minimum
Revenue from External Customer [Line Items]
Rental contract term	6 months
Rental Contracts, Excluding Large Horsepower Compressors | Maximum
Revenue from External Customer [Line Items]
Rental contract term	24 months
Rental Contracts, Large Horsepower Compressors | Maximum
Revenue from External Customer [Line Items]
Rental contract term	60 months
Customer Concentration Risk | One Customer | Accounts Receivable
Revenue from External Customer [Line Items]
Concentration risk, percentage	35.00%	35.00%
Customer Concentration Risk | Oxy | Sales and Rental Income
Revenue from External Customer [Line Items]
Concentration risk, percentage	30.00%	36.00%

Summary of Significant Accoun_5

Summary of Significant Accounting Policies - Schedule of Allowance for Doubtful Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning balance	$ (918)	$ (291)
Accruals	(329)	(664)
Recoveries	0	0
Write-offs	86	37
Ending balance	$ (1,161)	$ (918)

Summary of Significant Accoun_6

Summary of Significant Accounting Policies - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 7,229	$ 21,743
Add: ASC 842 rental revenue	60,826	56,701
Total revenue	68,055	78,444
Compressors - sales
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	2,211	15,185
Flares - sales
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	489	959
Other (Parts/Rebuilds) - sales
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	2,957	3,619
Service and maintenance
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 1,572	$ 1,980

Summary of Significant Accoun_7

Summary of Significant Accounting Policies - Contract Balances (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Accounts Receivable
Accounts receivable - contracts with customers	$ 3,243	$ 3,061
Accounts receivable - ASC 842	9,802	6,963
Total Accounts Receivable	13,045	10,024
Less: Allowance for doubtful accounts	(1,161)	(918)
Total Accounts Receivable, net	11,884	9,106
Deferred income	$ 1,103	$ 640

Summary of Significant Accoun_8

Summary of Significant Accounting Policies - Cumulative Effect of Changes from Adoption of ASU (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Assets
Right of use assets	$ 483	$ 604	$ 451	$ 0
Liabilities
Current operating leases	198	189	126	0
Long-term operating leases	285	415	325	0
Total lease liabilities	$ 483	$ 604	451	$ 0
Accounting Standards Update 2016-02
Assets
Right of use assets			451
Liabilities
Current operating leases			126
Long-term operating leases			325
Total lease liabilities			$ 451

Inventory - Schedule of Invento

Inventory - Schedule of Inventory (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Inventory Disclosure [Abstract]
Allowance for inventory obsolescence	$ 221	$ 24	$ 19
Raw materials - current	18,026	19,388
Work-in-process	1,900	1,692
Finished goods	0	0
Inventory - current	19,926	21,080
Raw materials - long term (net of allowances of $221 and $24, respectively)	1,065	1,068
Inventory - total	$ 20,991	$ 22,148

Inventory - Narrative (Details)

Inventory - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Inventory Disclosure [Abstract]
Inventory allowance, accrual	$ 251	$ 3,758
Allowance for inventory obsolescence	$ 221	$ 24	$ 19

Inventory - Schedule of Inven_2

Inventory - Schedule of Inventory Allowance (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Inventory Valuation Reserves [Roll Forward]
Beginning balance	$ (24)	$ (19)
Accruals	(251)	(3,758)
Write-offs	54	3,753
Ending balance	$ (221)	$ (24)

Rental Equipment, Property an_3

Rental Equipment, Property and Equipment - Schedule of Rental Equipment, Property and Equipment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 35,665	$ 34,716
Less accumulated depreciation	(13,916)	(12,847)
Property and equipment, net	21,749	21,869
Land
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 1,680	1,290
Building
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful life	39 years
Property and equipment, gross	$ 18,977	18,632
Building and leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful life	39 years
Property and equipment, gross	$ 1,168	1,168
Office equipment and furniture
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful life	5 years
Property and equipment, gross	$ 2,016	2,001
Software
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful life	5 years
Property and equipment, gross	$ 573	573
Machinery and equipment
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful life	7 years
Property and equipment, gross	$ 3,653	3,492
Vehicles
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful life	3 years
Property and equipment, gross	$ 7,598	7,560
Rental Equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	383,387	380,090
Less accumulated depreciation	(175,802)	(162,348)
Property and equipment, net	207,585	217,742
Rental Equipment | Compressor units
Property, Plant and Equipment [Line Items]
Property and equipment, gross	379,623	370,961
Rental Equipment | Work-in-progress
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 3,764	$ 9,129
Minimum
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful life	3 years
Minimum | Rental Equipment
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful life	15 years
Maximum
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful life	39 years
Maximum | Rental Equipment
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful life	25 years

Rental Equipment, Property an_4

Rental Equipment, Property and Equipment - Narrative (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2020USD ($)compressor	Dec. 31, 2019USD ($)compressor
Property, Plant and Equipment [Line Items]
Depreciation	$ 25,073	$ 23,143
Retirement of rental equipment	291	1,512
Loss On Retirement of Rental Equipment
Property, Plant and Equipment [Line Items]
Retirement of rental equipment	291	1,512
Property, Plant, and Equipment, Excluding Rental Equipment
Property, Plant and Equipment [Line Items]
Depreciation	$ 2,300	$ 1,700
Rental Compressor Unit
Property, Plant and Equipment [Line Items]
Number of units retired | compressor	216	327
Rental Equipment
Property, Plant and Equipment [Line Items]
Depreciation	$ 22,700	$ 21,400
Minimum
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful life	3 years
Minimum | Rental Equipment
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful life	15 years
Maximum
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful life	39 years
Maximum | Rental Equipment
Property, Plant and Equipment [Line Items]
Property and equipment, estimated useful life	25 years

Rental Equipment, Property an_5

Rental Equipment, Property and Equipment - Depreciation Expense by Product Line (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Depreciation	$ 25,073	$ 23,143
Corporate
Property, Plant and Equipment [Line Items]
Depreciation	495	235
Rentals | Operating Segments
Property, Plant and Equipment [Line Items]
Depreciation	24,255	22,596
Sales | Operating Segments
Property, Plant and Equipment [Line Items]
Depreciation	281	275
Service & Maintenance | Operating Segments
Property, Plant and Equipment [Line Items]
Depreciation	$ 42	$ 37

Rental Activity (Details)

Rental Activity (Details) $ in Thousands	Dec. 31, 2020USD ($)
Operating Leases, Future Minimum Payments Receivable [Abstract]
2021	$ 21,565
2022	15,084
2023	13,763
2024	8,590
2025	5,845
Thereafter	13,880
Total	$ 78,727
Minimum
Property Subject to or Available for Operating Lease [Line Items]
Rental contract term	6 months
Maximum
Property Subject to or Available for Operating Lease [Line Items]
Rental contract term	60 months

Leases - Narrative (Details)

Leases - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Lessee, Lease, Description [Line Items]
Right of use assets	$ 483	$ 604	$ 451	$ 0
Operating lease, liability	483	604	451	$ 0
Operating lease, cost	$ 217	$ 198
Accounting Standards Update 2016-02
Lessee, Lease, Description [Line Items]
Right of use assets			451
Operating lease, liability			$ 451
Minimum
Lessee, Lease, Description [Line Items]
Remaining lease term	1 year
Maximum
Lessee, Lease, Description [Line Items]
Remaining lease term	9 years

Leases - Balance Sheet Impact (

Leases - Balance Sheet Impact (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Leases [Abstract]
Right of use assets-operating leases	$ 483	$ 604	$ 451	$ 0
Current operating leases	198	189	126	0
Long-term operating leases	285	415	325	0
Total lease liabilities	$ 483	$ 604	$ 451	$ 0
Weighted average remaining lease term in years	1 year 6 months	2 years 7 months 6 days
Implicit Rate	3.20%	3.10%

Leases - Cash Flow Impact (Deta

Leases - Cash Flow Impact (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating lease cost	$ 550	$ 548
Short-term lease cost	333	350
Operating lease, cost	$ 217	$ 198

Leases - Future Maturities of L

Leases - Future Maturities of Lease Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018
Leases [Abstract]
2021	$ 211
2022	76
2023	38
2024	38
2025	38
Thereafter	130
Total lease payments	531
Less: Imputed interest	(48)
Total	$ 483	$ 604	$ 451	$ 0

Goodwill (Details)

Goodwill (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Goodwill and Intangible Assets Disclosure [Abstract]
Impairment of goodwill	$ 0	$ 10,039

Intangibles (Details)

Intangibles (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Intangible Assets [Line Items]
Amortization expense	$ 125,000	$ 125,000
Finite-Lived Intangible Assets, Net, Amortization Expense, Fiscal Year Maturity [Abstract]
2020	125,000
2021	125,000
2022	125,000
2023	125,000
2024	125,000
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Value	3,159,000	3,159,000
Accumulated Amortization	2,008,000	1,883,000
Net Book Value	1,151,000	1,276,000
Impairment of intangible assets	0	0
Trade Name
Finite-Lived Intangible Assets, Net [Abstract]
Gross Carrying Value	654,000	654,000
Accumulated Amortization	0	0
Net Book Value	$ 654,000	654,000
Developed Technology
Finite-Lived Intangible Assets, Net [Abstract]
Intangible assets, useful life	20 years
Gross Carrying Value	$ 2,505,000	2,505,000
Accumulated Amortization	2,008,000	1,883,000
Net Book Value	$ 497,000	$ 622,000

Credit Facility (Details)

Credit Facility (Details)	12 Months Ended
	Dec. 31, 2020USD ($)loan	Dec. 31, 2019USD ($)
Line of Credit Facility [Line Items]
Line of credit	$ 417,000	$ 417,000
Weighted average interest rate	2.75%
Revolving Credit Facility
Line of Credit Facility [Line Items]
Aggregate credit agreement commitment	$ 30,000,000
Potential increase in borrowing capacity	20,000,000
Potential maximum borrowing capacity	$ 50,000,000
Borrowing base, component, % of eligible accounts receivable	80.00%
Borrowing base, component, % of eligible inventory	50.00%
Borrowing base, allowable share of total commitment amount attributable to inventory component	50.00%
Borrowing base, component, % of eligible equipment inventory	75.00%
Borrowing base amount available	$ 29,500,000
Line of credit	$ 417,000
Revolving Credit Facility | Minimum
Line of Credit Facility [Line Items]
Minimum commitment coverage ratio allowed	2
Revolving Credit Facility | Maximum
Line of Credit Facility [Line Items]
Maximum leverage ratio allowed	2.50
Default trigger, certain defaults of other company indebtedness, amount	$ 50,000
Default trigger, rendering of certain judgments, amount	$ 150,000
Revolving Credit Facility | LIBOR Rate
Line of Credit Facility [Line Items]
Variable rate, applicable margin	1.50%
Revolving Credit Facility | LIBOR Rate | Maximum
Line of Credit Facility [Line Items]
Reference rate, number of allowable LIBOR-based borrowings outstanding (in loans) | loan	3
Revolving Credit Facility | CB Floating Rate
Line of Credit Facility [Line Items]
Variable rate, applicable margin	1.25%

CARES Act Loan (Details)

CARES Act Loan (Details) $ in Millions	Apr. 10, 2020USD ($)
Paycheck Protection Program Loan | Unsecured Debt
Debt Instrument [Line Items]
Proceeds from entering into loan	$ 4.6

Income Taxes - Components of Pr

Income Taxes - Components of Provision for Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Current benefit (provision):
Federal benefit (expense)		$ 15,587	$ 86
State (expense) benefit		(149)	(55)
Total current benefit (provision)		15,438	31
Deferred benefit (provision):
Federal benefit (expense)		(10,234)	662
State	$ (412)		0
Total deferred benefit (expense)		(10,646)	662
Total income tax benefit		$ 4,792	$ 693

Income Taxes - Income Tax Recon

Income Taxes - Income Tax Reconciliation (Details)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Statutory rate	21.00%	21.00%
State and local taxes	(17.00%)	(3.70%)
Uncertain tax position	0.00%	0.00%
Goodwill impairment	0.00%	(13.70%)
Research and development credit	0.00%	1.40%
Stock based compensation	(13.10%)	(0.80%)
Nondeductible compensation	(11.60%)	(0.30%)
Effect of CARES Act	180.30%	0.00%
Other	0.50%	0.90%
Effective rate	160.10%	4.80%
Deferred re-measurement for rate change	0	0
Effective rate	160.10%	4.80%

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($)	3 Months Ended
	Mar. 31, 2020	Dec. 31, 2020	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Federal income tax receivable	$ 15,000,000	$ 11,538,000	$ 0
Deferred tax liability increase due to tax law change	$ 10,100,000
Net operating loss carryforward		11,600,000
Amount of reserve for uncertain tax positions		$ 0	$ 0

Income Taxes - Components of De

Income Taxes - Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Deferred income tax assets:
Net operating loss	$ 3,361	$ 1,519
Research and development credits	1,363	161
Stock compensation	175	580
Deferred compensation	705	389
Other	398	160
Total deferred income tax assets	6,002	2,809
Deferred income tax liabilities:
Property and equipment	(47,626)	(33,761)
Goodwill and other intangible assets	(266)	(291)
Total deferred income tax liabilities	(47,892)	(34,052)
Net deferred income tax liabilities	$ (41,890)	$ (31,243)

Deferred Compensation Plans (De

Deferred Compensation Plans (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Compensation Related Costs [Abstract]
Participant's maximum compensation deferral percentage	90.00%
Company owned life insurance	$ 2,000,000	$ 1,500,000
Gain (loss) on company owned life insurance	168,000	218,800
Deferred compensation obligation	$ 2,200,000	$ 1,700,000
Deferred restricted stock shares (in shares)	45,998	85,565
Deferred compensation arrangement with individual, shares issued (in shares)	145,702	89,187
Deferred compensation arrangement, fair value of shares issued	$ 2,200,000	$ 1,700,000

Stockholders' Equity (Details)

Stockholders' Equity (Details) - shares	Dec. 31, 2020	Dec. 31, 2019
Stockholders' Equity Attributable to Parent [Abstract]
Preferred stock, shares authorized (in shares)	5,000,000	5,000,000
Preferred stock, shares issued (in shares)	0	0
Preferred stock, shares outstanding (in shares)	0	0

Stock-Based and Other Long-Te_3

Stock-Based and Other Long-Term Incentive Compensation - Restricted Stock Narrative (Details) - Restricted Stock $ in Millions	Apr. 28, 2021	Apr. 28, 2020shares	Jun. 18, 2014shares	Dec. 31, 2020USD ($)independent_directorshares	Dec. 31, 2019USD ($)shares	Jun. 20, 2019shares	Dec. 31, 2018shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares outstanding (in shares)				258,101	279,766		214,630
Granted (in shares)				123,185	199,810
Stock based compensation expense | $				$ 2.2	$ 2.5
Total unrecognized compensation expense | $				$ 1.8
Recognition period				3 years
Chief Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period		3 years
Granted (in shares)		94,133
Chief Financial Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)		10,000
Vice President of Technical Services
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)		10,000
Executive Officer | Forecast
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	3 years
Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period				1 year
Granted (in shares)				4,432
Number of independent directors | independent_director				4
2009 Restricted Stock/Units Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Additional shares authorized (in shares)			500,000
Number of shares authorized (in shares)			800,000
Shares outstanding (in shares)				34,899
Award vesting period				1 year
Issuance under the equity incentive plan (in shares)				200,141
Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)						500,000
Shares outstanding (in shares)				223,202
Award vesting period				3 years

Stock-Based and Other Long-Te_4

Stock-Based and Other Long-Term Incentive Compensation - Restricted Stock Activity (Details) - Restricted Stock - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2020
Number  of Shares
Outstanding, beginning of period (in shares)	279,766	214,630
Granted (in shares)	123,185	199,810
Vested (in shares)	(144,850)	(134,674)
Canceled/Forfeited (in shares)	0	0
Outstanding, beginning of period (in shares)	258,101	279,766	214,630
Weighted Average Exercise Price
Outstanding, beginning of period (in dollars per share)	$ 20.15	$ 25.51
Granted (in dollars per share)	5.68	17.16
Vested (in dollars per share)	20.82	24.26
Canceled/Forfeited (in dollars per share)	0	0
Outstanding, end of period (in dollars per share)	$ 12.87	$ 20.15	$ 25.51
Weighted Average Remaining Contractual Life (years)
Weighted average remaining contractual life (years)	8 years 7 months 9 days	8 years 9 months 7 days	8 years 10 months 6 days
Aggregate Intrinsic Value
Outstanding, begging balance	$ 3,430	$ 3,529
Granted	700	3,433
Vested	946	2,807
Outstanding, ending balance	$ 3,430	$ 3,529	$ 3,529	$ 2,447

Stock-Based and Other Long-Te_5

Stock-Based and Other Long-Term Incentive Compensation - Other Long-Term Incentive Compensation Narrative (Details) - Other Long-Term Incentive Compensation $ in Thousands	Apr. 28, 2020USD ($)independent_director	Dec. 31, 2020USD ($)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted	$ 1,100
Award vesting period	3 years
Stock based compensation expense		$ 400
Total unrecognized compensation expense		$ 800
Recognition period		2 years 3 months
Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted	$ 50
Award vesting period	1 year
Number of independent directors | independent_director	4

Stock-Based and Other Long-Te_6

Stock-Based and Other Long-Term Incentive Compensation - Stock Options Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Jun. 16, 2016
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Granted (in shares)	5,000	0
Weighted average grant date fair value of options granted (in dollars per share)	$ 2.07	$ 0	$ 0
Total intrinsic value of options exercised	$ 0	$ 474,000
Proceeds from exercise of stock options	0	506,000
Unrecognized compensation cost related to stock options	0
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock based compensation expense	$ 19,366	$ 124,000
Stock Options | 1998 Stock Option Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	3 years
Award expiration period	10 years
Stock Options | 1998 Stock Option Plan | Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)				1,000,000
Number of shares available for grant (in shares)	384,503

Stock-Based and Other Long-Te_7

Stock-Based and Other Long-Term Incentive Compensation - Valuation Assumptions (Details)	12 Months Ended
	Dec. 31, 2020
Share-based Payment Arrangement [Abstract]
Risk free rate	0.48%
Expected life	6 years 7 months 2 days
Expected volatility	42.33%
Expected dividend yield	0.00%

Stock-Based and Other Long-Te_8

Stock-Based and Other Long-Term Incentive Compensation - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Number  of Shares
Outstanding, beginning of period (in shares)	208,334	283,686
Granted (in shares)	5,000	0
Exercised (in shares)	0	(56,352)
Canceled/Forfeited (in shares)	(12,000)	(8,000)
Expired (in shares)	(40,000)	(11,000)
Outstanding, end of period (in shares)	161,334	208,334	283,686
Exercisable (in shares)	161,334
Weighted Average Exercise Price
Outstanding, beginning of period (in dollars per share)	$ 23.67	$ 20.46
Granted (in dollars per share)	4.91	0
Exercised (in dollars per share)	0	8.97
Canceled/Forfeited, weighted average exercise price (in dollars per share)	20.20	21.60
Expired (in dollars per share)	19.11	17.74
Outstanding, end of period (in dollars per share)	24.48	$ 23.67	$ 20.46
Exercisable (in dollars per share)	$ 24.48
Weighted Average Remaining Contractual Life (years)
Outstanding, weighted average remaining contractual life	3 years 5 months 23 days	3 years 7 months 28 days	3 years 6 months 29 days
Exercisable, weighted average remaining contractual life	3 years 5 months 23 days
Aggregate Intrinsic Value
Outstanding, aggregate intrinsic value	$ 0	$ 0	$ 434
Exercised, aggregate intrinsic value	0	$ 474
Canceled/Forfeited, aggregate intrinsic value	23,750
Exercisable, aggregate intrinsic value	$ 0

Stock-Based and Other Long-Te_9

Stock-Based and Other Long-Term Incentive Compensation - Stock Options by Exercise Price Range (Details)	12 Months Ended
	Dec. 31, 2020$ / sharesshares
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options outstanding, shares (in shares) | shares	161,334
Options outstanding, weighted average remaining contractual life (years)	3 years 5 months 23 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 24.48
Options exercisable, shares (in shares) | shares	161,334
Options exercisable, weighted average exercise price (in dollars per share)	$ 24.48
Range One
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
Options outstanding, shares (in shares) | shares	24,500
Options outstanding, weighted average remaining contractual life (years)	4 months 28 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 16.80
Options exercisable, shares (in shares) | shares	24,500
Options exercisable, weighted average exercise price (in dollars per share)	$ 16.80
Range Two
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Range of exercise prices, lower limit (in dollars per share)	18.01
Range of exercise prices, upper limit (in dollars per share)	$ 22
Options outstanding, shares (in shares) | shares	20,500
Options outstanding, weighted average remaining contractual life (years)	2 years 2 months 19 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 18.75
Options exercisable, shares (in shares) | shares	20,500
Options exercisable, weighted average exercise price (in dollars per share)	$ 18.75
Range Three
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
Options outstanding, shares (in shares) | shares	42,167
Options outstanding, weighted average remaining contractual life (years)	4 years 3 months 10 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 22.90
Options exercisable, shares (in shares) | shares	42,167
Options exercisable, weighted average exercise price (in dollars per share)	$ 22.90
Range Four
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
Options outstanding, shares (in shares) | shares	30,000
Options outstanding, weighted average remaining contractual life (years)	6 years 1 month 17 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 28.15
Options exercisable, shares (in shares) | shares	30,000
Options exercisable, weighted average exercise price (in dollars per share)	$ 28.15
Range Five
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
Options outstanding, shares (in shares) | shares	44,167
Options outstanding, weighted average remaining contractual life (years)	3 years 2 months 19 days
Options outstanding, weighted average exercise price (in dollars per share)	$ 30.41
Options exercisable, shares (in shares) | shares	44,167
Options exercisable, weighted average exercise price (in dollars per share)	$ 30.41

Stock-Based and Other Long-T_10

Stock-Based and Other Long-Term Incentive Compensation - Summary of Unvested Stock Options (Details) - $ / shares	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Shares
Unvested, beginning of period (in shares)	10,433
Granted (in shares)	5,000	0
Vested (in shares)	(10,433)
Canceled/Forfeited (in shares)	(5,000)
Unvested, end of period (in shares)	0	10,433
Weighted Average Grant Date Fair Value
Unvested, beginning of period (in dollars per share)	$ 11.93
Granted (in dollars per share)	2.07	$ 0	$ 0
Vested (in dollars per share)	11.93
Canceled/Forfeited (in dollars per share)	2.07
Unvested, end of period (in dollars per share)	$ 0	$ 11.93

(Loss) Earnings per Share (Deta

(Loss) Earnings per Share (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Numerator:
Net loss	$ 1,808	$ (13,864)
Denominator for basic net (loss) income per common share:
Weighted average common shares outstanding (in shares)	13,224,000	13,114,000
Denominator for diluted net (loss) income per share:
Dilutive effect of stock options and restricted shares (in shares)	37,000	0
Weighted average common shares outstanding, Diluted (in shares)	13,261,000	13,114,000
(Loss) earnings per common share:
Basic (in dollars per share)	$ 0.14	$ (1.06)
Diluted (in dollars per share)	$ 0.14	$ (1.06)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities (in shares)	221,061	279,766
Stock Options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive securities (in shares)	161,334	208,334

Related Party (Details)

Related Party (Details) - Corporate Joint Venture - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2016
Related Party Transaction [Line Items]
Purchases from joint venture	$ 1
N-G, LLC
Related Party Transaction [Line Items]
Percent ownership		50.00%
Genis Holdings, LLC | N-G, LLC
Related Party Transaction [Line Items]
Percent ownership		50.00%