Power Solutions International (PSIX) 10-Q 16 May 22 2022 Q1 Quarterly report Financial data

Cover Page

Cover Page - shares	3 Months Ended
	Mar. 31, 2022	May 09, 2022
Cover [Abstract]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2022
Document Transition Report	false
Entity File Number	001-35944
Entity Registrant Name	POWER SOLUTIONS INTERNATIONAL, INC.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	33-0963637
Entity Address, Address Line One	201 Mittel Drive
Entity Address, City or Town	Wood Dale
Entity Address, State or Province	IL
Entity Address, Postal Zip Code	60191
City Area Code	630
Local Phone Number	350-9400
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		22,926,875
Entity Central Index Key	0001137091
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q1
Amendment Flag	false

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Cash and cash equivalents	$ 2,267	$ 6,255
Restricted cash	3,160	3,477
Accounts receivable, net of allowances of $3,623 and $3,420 as of March 31, 2022 and December 31, 2021, respectively	71,250	65,110
Income tax receivable	4,497	4,276
Inventories, net	139,061	142,192
Prepaid expenses and other current assets	11,255	8,918
Total current assets	231,490	230,228
Property, plant and equipment, net	15,985	17,344
Intangible assets, net	7,243	7,784
Goodwill	29,835	29,835
Other noncurrent assets	14,415	15,347
TOTAL ASSETS	298,968	300,538
Current liabilities:
Accounts payable	82,603	93,256
Current maturities of long-term debt	223	254
Revolving line of credit	130,000	130,000
Other short-term financing	40,000	25,000
Other accrued liabilities	36,501	34,801
Total current liabilities	289,327	283,311
Deferred income taxes	1,388	1,016
Long-term debt, net of current maturities	25,586	25,636
Noncurrent contract liabilities	3,565	3,330
Other noncurrent liabilities	23,521	29,268
TOTAL LIABILITIES	343,387	342,561
STOCKHOLDERS’ (DEFICIT) EQUITY
Preferred stock – $0.001 par value. Shares authorized: 5,000. No shares issued and outstanding at all dates.	0	0
Common stock – $0.001 par value; 50,000 shares authorized; 23,117 shares issued; 22,927 and 22,926 shares outstanding at March 31, 2022 and December 31, 2021, respectively	23	23
Additional paid-in capital	157,639	157,436
Accumulated deficit	(200,965)	(198,366)
Treasury stock, at cost, 190 and 191 shares at March 31, 2022 and December 31, 2021, respectively	(1,116)	(1,116)
TOTAL STOCKHOLDERS’ (DEFICIT) EQUITY	(44,419)	(42,023)
TOTAL LIABILITIES AND STOCKHOLDERS’ (DEFICIT) EQUITY	$ 298,968	$ 300,538

CONSOLIDATED BALANCE SHEETS (Pa

CONSOLIDATED BALANCE SHEETS (Parenthetical) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Current assets:
Accounts receivable allowance	$ 3,623	$ 3,420
STOCKHOLDERS’ (DEFICIT) EQUITY
Preferred stock, par value (in dollars per share)	$ 0.001	$ 0.001
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, par value (in dollars per share)	$ 0.001	$ 0.001
Common stock, shares authorized (in shares)	50,000,000	50,000,000
Common stock, shares issued (in shares)	23,117,000	23,117,000
Common stock, shares outstanding (in shares)	22,927,000	22,926,000
Treasury stock (in shares)	190,000	191,000

CONSOLIDATED STATEMENTS OF OPER

CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Income Statement [Abstract]
Net sales	$ 98,947	$ 100,171
Cost of sales	82,229	93,101
Gross profit	16,718	7,070
Operating expenses:
Research, development and engineering expenses	4,560	6,224
Selling, general and administrative expenses	11,385	15,811
Amortization of intangible assets	541	634
Total operating expenses	16,486	22,669
Operating income (loss)	232	(15,599)
Other expense, net:
Interest expense	2,445	2,161
Total other expense, net	2,445	2,161
Loss before income taxes	(2,213)	(17,760)
Income tax expense	386	390
Net loss	$ (2,599)	$ (18,150)
Weighted-average common shares outstanding:
Basic (in shares)	22,927	22,892
Diluted (in shares)	22,927	22,892
Loss per common share:
Basic (in dollars per share)	$ (0.11)	$ (0.79)
Diluted (in dollars per share)	$ (0.11)	$ (0.79)

CONSOLIDATED STATEMENTS OF STOC

CONSOLIDATED STATEMENTS OF STOCKHOLDERS' (DEFICIT) EQUITY - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Accumulated Deficit	Treasury Stock
Beginning balance at Dec. 31, 2020	$ 6,097	$ 23	$ 157,262	$ (149,894)	$ (1,294)
Increase (Decrease) in Stockholders' Equity
Net loss	(18,150)			(18,150)
Stock-based compensation expense	109		109
Common stock issued for stock-based awards, net	(1)				(1)
Ending balance at Mar. 31, 2021	(11,945)	23	157,371	(168,044)	(1,295)
Beginning balance at Dec. 31, 2021	(42,023)	23	157,436	(198,366)	(1,116)
Increase (Decrease) in Stockholders' Equity
Net loss	(2,599)			(2,599)
Stock-based compensation expense	203		203
Ending balance at Mar. 31, 2022	$ (44,419)	$ 23	$ 157,639	$ (200,965)	$ (1,116)

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Cash (used in) provided by operating activities
Net loss	$ (2,599)	$ (18,150)
Adjustments to reconcile net loss to net cash (used in) provided by operating activities:
Amortization of intangible assets	541	634
Depreciation	1,206	1,266
Stock-based compensation expense	203	109
Amortization of financing fees	837	1,158
Deferred income taxes	372	369
Other adjustments, net	343	574
Changes in operating assets and liabilities:
Accounts receivable, net	(6,140)	7,620
Inventory, net	3,182	(1,363)
Prepaid expenses and other assets	(739)	(84)
Accounts payable	(10,777)	24,287
Other current liabilities	1,706	(11,144)
Other noncurrent liabilities	(5,512)	405
Net cash (used in) provided by operating activities	(17,377)	5,681
Cash used in investing activities
Capital expenditures	(116)	(617)
Other investing activities, net	0	10
Net cash used in investing activities	(116)	(607)
Cash provided by (used in) financing activities
Repayments of long-term debt and lease liabilities	(87)	(102)
Proceeds from short-term financings	15,000	0
Payments of deferred financing costs	(1,725)	(2,536)
Net cash provided by (used in) financing activities	13,188	(2,638)
Net (decrease) increase in cash, cash equivalents, and restricted cash	(4,305)	2,436
Cash, cash equivalents, and restricted cash at beginning of the period	9,732	24,267
Cash, cash equivalents, and restricted cash at end of the period	5,427	26,703
Reconciliation of cash, cash equivalents, and restricted cash to the Consolidated Balance Sheets
Cash and cash equivalents	2,267	23,404
Restricted cash	3,160	3,299
Total cash, cash equivalents, and restricted cash	$ 5,427	$ 26,703

Summary of Significant Accounti

Summary of Significant Accounting Policies and Other Information	3 Months Ended
	Mar. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Summary of Significant Accounting Policies and Other Information	Summary of Significant Accounting Policies and Other Information Nature of Business Operations Power Solutions International, Inc. (“Power Solutions,” “PSI” or the “Company”), a Delaware corporation, is a global producer and distributor of a broad range of high-performance, certified, low-emission power systems, including alternative-fueled power systems for original equipment manufacturers (“OEMs”) of off-highway industrial equipment and certain on-road vehicles and large custom-engineered integrated electrical power generation systems. The Company’s customers include large, industry-leading and multinational organizations. The Company’s products and services are sold predominantly to customers throughout North America as well as to customers located throughout the Pacific Rim and Europe. The Company’s power systems are highly engineered, comprehensive systems which, through the Company’s technologically sophisticated development and manufacturing processes, including its in-house design, prototyping, testing and engineering capabilities and its analysis and determination of the specific components to be integrated into a given power system (driven in large part by emission standards and cost considerations), allow the Company to provide its customers with power systems customized to meet specific OEM application requirements, other technical customers’ specifications and requirements imposed by environmental regulatory bodies. The Company’s power system configurations range from a basic engine integrated with appropriate fuel system components to completely packaged power systems that include any combination of cooling systems, electronic systems, air intake systems, fuel systems, housings, power takeoff systems, exhaust systems, hydraulic systems, enclosures, brackets, hoses, tubes and other assembled componentry. The Company also designs and manufactures large, custom-engineered integrated electrical power generation systems for both standby and prime power applications. The Company purchases engines from third-party suppliers and produces internally designed engines, all of which are then integrated into its power systems. Of the other components that the Company integrates into its power systems, a substantial portion consist of internally designed components and components for which it coordinates significant design efforts with third-party suppliers, with the remainder consisting largely of parts that are sourced off-the-shelf from third-party suppliers. Some of the key components (including purchased engines) embody proprietary intellectual property of the Company’s suppliers. As a result of its design and manufacturing capabilities, the Company is able to provide its customers with a power system that can be incorporated into a customer’s specified application. In addition to the certified products described above, the Company sells diesel, gasoline and non-certified power systems and aftermarket components. Stock Ownership and Control In March 2017, the Company executed a share purchase agreement (the “SPA”) with Weichai America Corp., a wholly-owned subsidiary of Weichai Power Co., Ltd. (HK2338, SZ000338) (herein collectively referred to as “Weichai”). Under the terms of the SPA, Weichai invested $60.0 million in the Company purchasing a combination of newly issued Common and Preferred Stock as well as a stock purchase warrant (the “Weichai Warrant”). With the exercise of the Weichai Warrant in April 2019, Weichai owns a majority of the outstanding shares of the Company’s common stock par value $0.001 (“Common Stock”). As a result, Weichai is able to exercise control over matters requiring stockholders’ approval, including the election of the directors, amendment of the Company’s Certificate of Incorporation and approval of significant corporate transactions. This control could have the effect of delaying or preventing a change of control of the Company or changes in management and will make the approval of certain transactions impractical without the support of Weichai. Weichai also entered into an Investor Rights Agreement (the “Rights Agreement”) with the Company upon execution of the SPA. The Rights Agreement provides Weichai with representation on the Company’s Board of Directors (the “Board”) and management representation rights. Weichai currently has four representatives on the Board, which constitutes the majority of the directors serving on the Board. According to the Rights Agreement, during any period when the Company is a “controlled company” within the meaning of the NASDAQ Stock Market (“NASDAQ”) Listing Rules, it will take such measures as to avail itself of the “controlled company” exemptions available under Rule 5615 of the NASDAQ Listing Rules of Rules 5605(b), (d) and (e). Going Concern Considerations O n March 25, 2022, the Company amended and restated its $130.0 million uncommitted senior secured revolving credit agreement with Standard Chartered (the “Second Amended and Restated Credit Agreement”). The Second Amended and Restated Credit Agreement extends the maturity date of loans outstanding under its previous credit facility to the earlier of March 24, 2023 or the demand of Standard Chartered. The Second Amended and Restated Credit Agreement is subject to customary events of default and covenants, including minimum consolidated EBITDA and Consolidated Interest Coverage Ratio covenants for the second and third quarters of 2022. Borrowings under the Second Amended and Restated Credit Agreement will incur interest at either the alternate base rate or the Secured Overnight Financing Rate (“SOFR”) plus 2.95% per annum. The Second Amended and Restated Credit Agreement continues to be secured by substantially all of the Company’s assets and provides Standard Chartered the right to demand payment of any and all of the outstanding borrowings and other amounts owed under the Second Amended and Restated Credit Agreement at any point in time prior to the maturity date at Standard Chartered’s discretion. Furthermore, the Second Amended and Restated Credit Agreement grants Standard Chartered a power of attorney (POA) to submit a borrowing request to Weichai under the amended first shareholder’s loan agreement (see discussion below) if the Company did not submit a borrowing request to Weichai within five business days of receiving a request from Standard Chartered to submit said borrowing request. As of March 31, 2022, the Company had $130.0 million outstanding under the Second Amended and Restated Credit Agreement. See Note 6. Debt , for further information regarding the terms and conditions of the Company’s debt agreements. In connection with the Second Amended and Restated Credit Agreement, on March 25, 2022, the Company also amended two of its shareholder’s loan agreements with Weichai, to among other things, extend the maturities thereof. The amended first shareholder’s loan agreement (the “Amended First Shareholder’s Loan Agreement”) continues to provide the Company with a $130.0 million subordinated loan under which Weichai is obligated to advance funds solely for purposes of repaying outstanding borrowings under the Second Amended and Restated Credit Agreement if the Company is unable to pay such borrowings. The amended second shareholder’s loan agreement (the “Amended Second Shareholder’s Loan Agreement”) continues to provide the Company with a $25.0 million subordinated loan at the discretion of Weichai. The maturity of the Amended First Shareholder’s Loan Agreement was extended to April 24, 2023 and the maturity of the Amended Second Shareholder’s Loan Agreement was extended to May 20, 2023. The Company has covenanted to secure any amounts borrowed under either of the agreements upon payment in full of all amounts outstanding under the Second Amended and Restated Credit Agreement. As of March 31, 2022, there were no borrowings under the Amended First Shareholder’s Loan Agreement and $25.0 million under the Amended Second Shareholder’s Loan Agreement. The Company is also party to another shareholder’s loan agreement with Weichai, which was entered into on December 10, 2021 (the “Third Shareholder’s Loan Agreement”). The Third Shareholder’s Loan Agreement provides the Company with a $50.0 million uncommitted facility that is subordinated to the Second Amended and Restated Credit Agreement and any borrowing requests made under the Third Shareholder’s Loan Agreement are subject to Weichai’s discretionary approval. Borrowings under the Third Shareholder’s Loan Agreement bear interest at LIBOR plus 4.50% and can be used for general corporate purposes, except for certain legal expenditures which require additional approval from Weichai. The Third Shareholder’s Loan Agreement expires on November 30, 2022, with any outstanding principal and accrued interest due upon maturity. As of March 31, 2022, the Company had $40.0 million outstanding under the Third Shareholder’s Loan Agreement. On April 20, 2022, the Company entered into an additional shareholder’s loan agreement with Weichai (the “Fourth Shareholder’s Loan Agreement”). The Fourth Shareholder’s Loan Agreement, which matures on March 31, 2023, provides the Company with access to up to $30.0 million of credit at the discretion of Weichai to supplement the Company’s working capital. The Fourth Shareholder’s Loan Agreement is subordinated in all respects to the Second Amended and Restated Credit Agreement. Borrowings under the Amended First Shareholder’s Loan Agreement, the Amended Second Shareholder’s Loan Agreement and the Fourth Shareholder’s Loan Agreement will incur interest at the applicable SOFR, plus 4.65% per annum. Further, if the applicable term SOFR is negative, the interest rate per annum shall be deemed as 4.65% per annum. If the interest rate for any loan is lower than Weichai’s borrowing cost, the interest rate for such loan shall be equal to Weichai’s borrowing cost plus 1%. As of March 31, 2022, the Company’s total outstanding debt obligations under the Second Amended and Restated Credit Agreement, the Amended Second Shareholder’s Loan Agreement, the Third Shareholder’s Loan Agreement and for finance leases and other debt were $195.8 million in the aggregate, and its cash and cash equivalents were $2.3 million. See Note 6. Debt , for additional information. Significant uncertainties exist about the Company’s ability to refinance, extend, or repay its outstanding indebtedness, maintain sufficient liquidity to fund its business activities, and maintain compliance with the covenants and other requirements under the Company’s debt arrangements. Without additional financing, the Company anticipates that it will not have sufficient cash and cash equivalents to repay amounts owing under its existing debt arrangements as they become due. In order to provide the Company with a more permanent source of liquidity, management plans to seek an extension and amendment and/or replacement of its existing debt agreements or seek additional liquidity from its current or other lenders before the maturity dates in 2022 and 2023 as discussed above. There can be no assurance that the Company’s management will be able to successfully complete an extension and amendment of its existing debt agreements or obtain new financing on acceptable terms, when required or if at all. These consolidated financial statements do not include any adjustments that might result from the outcome of the Company’s efforts to address these issues. Furthermore, if the Company cannot raise capital on acceptable terms, it may not, among other things, be able to do the following: • continue to expand the Company’s research and product investments and sales and marketing organization; • continue to fund and expand operations both organically and through acquisitions; and • respond to competitive pressures or unanticipated working capital requirements. Additionally, as discussed further below, the global economy continues to be impacted by the outbreak of the COVID-19 that was first declared a global pandemic (the “COVID-19 pandemic”) in March 2020. The potential for continued disruptions, economic uncertainty, and unfavorable oil and gas market dynamics may continue to have a material adverse impact on the results of operations, financial position and liquidity of the Company. The Company’s management has concluded that, due to uncertainties surrounding the Company’s future ability to refinance, extend and amend, or repay its outstanding indebtedness under its existing debt arrangements, maintain sufficient liquidity to fund its business activities, and maintain compliance with the covenants and other requirements under the Second Amended and Restated Credit Agreement in the future, substantial doubt exists as to its ability to continue as a going concern within one year after the date that these financial statements are issued. The Company’s plans to alleviate the substantial doubt about its ability to continue as a going concern may not be successful, and it may be forced to limit its business activities or be unable to continue as a going concern, which would have a material adverse effect on its results of operations and financial condition. The consolidated financial statements included herein have been prepared assuming that the Company will continue as a going concern and contemplating the realization of assets and the satisfaction of liabilities and commitments in the normal course of business. The Company’s ability to continue as a going concern is dependent on generating profitable operating results, having sufficient liquidity, maintaining compliance with the covenants and other requirements under the Second Amended and Restated Credit Agreement in the future, and extending and amending, refinancing or repaying the indebtedness outstanding under the Company’s existing debt arrangements. COVID-19 and other Recent Business Impacts The ongoing COVID-19 pandemic has resulted in the implementation of significant governmental measures to control the spread of the virus, including quarantines, travel restrictions, business shutdowns and restrictions on the movement of people in the United States and abroad. During 2020 and 2021, as a result of the COVID-19 pandemic, the global economy experienced substantial turmoil, which led to challenging market conditions across certain areas of the Company’s business. In addition, due to unprecedented decreases in demand, an oil price war, and economic uncertainty resulting from the COVID-19 pandemic, average crude oil prices were considerably lower in 2020 as compared to prices at the end of 2019 but showed signs of improvement in 2021, and through the first quarter of 2022. However, although rig counts in the U.S. oil markets increased during 2021 and through the first quarter of 2022, average rig counts remained below pre-pandemic levels. The Company also believes that capital spending within the U.S. oil and gas industry remains well below pre-pandemic levels. While the Company saw an increase of sales to customers with traditional exposure to the oil and gas markets during the first quarter of 2022, as compared to the prior year, sales remain below 2019 levels. A significant portion of the Company’s sales and profitability has historically been derived from the sale of products that are used within the oil and gas industry. In addition, the Company continued to experience delays in its supply chain during the first quarter of 2022 due to temporary shortages of raw materials and container delays of overseas materials as bottlenecks occurred at ports in Asia and North America. This, in turn, caused delivery delays to some of the Company’s customers. The Company also experienced inflationary cost pressures for certain materials and shipping-related costs. Additionally, the Company continues to experience ongoing tariff costs for products that did not receive exclusions. The Company is working to mitigate the impact of these matters through price increases and other measures, such as seeking certain tariff exclusions, where possible. The potential for continued disruptions, economic uncertainty, and unfavorable oil and gas market dynamics may have a material adverse impact on the timing of delivery of customer orders and the levels of future customer orders. The Company performs its annual goodwill impairment test as of October 1, or more frequently if an event occurs or circumstances change that would more likely than not reduce the fair value of a reporting unit below its carrying value. As further discussed in Item 8., Note 5. Goodwill and Other Intangibles , the Company completed its annual goodwill impairment assessment as of October 1, 2021 and concluded that goodwill was not impaired. It is reasonably possible that potential adverse impacts of the factors noted above could result in the recognition of material impairments of goodwill and other long-lived assets or other related charges in future periods. Lastly, during 2021, the Company incurred significantly higher legal costs due to its obligation to indemnify certain former officers and employees as a result of exhaustion of its directors and officers insurance during the early part of 2020. In particular, spending activity was elevated during the first nine months of 2021 as a result of the USAO trial involving former officers and employees of the Company. With a verdict reached in the USAO trial matter involving former officers and employees in September 2021, the Company believes its costs related to the matter will cease. Accordingly, the Company saw a substantial decline in these costs during the first quarter of 2022. However, at this time, the Company is not able to estimate the potential future amount of its indemnity obligations related to the pending SEC matter involving prior officers and employees. See Note 9. Commitments and Contingencies for further discussion of the Company’s indemnification obligations. Accordingly, the above challenges may continue to have a material adverse impact on the Company’s future results of operations, financial position, and liquidity. Basis of Presentation and Consolidation The Company is filing this Form 10-Q for the three months ended March 31, 2022, which contains unaudited consolidated financial statements as of March 31, 2022 and for the three months ended March 31, 2022 and 2021. The consolidated financial statements include the accounts of Power Solutions International, Inc. and its wholly-owned subsidiaries and majority-owned subsidiaries in which the Company exercises control. The foregoing financial information was prepared in accordance with generally accepted accounting principles in the United States (“U.S. GAAP”) and rules and regulations of the SEC for interim financial reporting. All intercompany balances and transactions have been eliminated in consolidation. Certain information and note disclosures normally included in the Company’s annual financial statements prepared in accordance with U.S. GAAP have been condensed or omitted. The accompanying consolidated financial statements should be read in conjunction with, and have been prepared in accordance with accounting policies reflected in, the consolidated financial statements and related notes, included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2021 (“the 2021 Annual Report”). The Company’s significant accounting policies are described in the aforementioned 2021 Annual Report. Included below are certain updates to those policies. The accompanying interim financial information is unaudited; however, the Company believes the financial information reflects all adjustments (consisting of items of a normal recurring nature) necessary for a fair presentation of financial position, results of operations and cash flows in conformity with U.S. GAAP. Operating results for interim periods are not necessarily indicative of annual operating results. The Company operates as one business and geographic operating segment. Operating segments are defined as components of a business that can earn revenue and incur expenses for which discrete financial information is available that is evaluated on a regular basis by the chief operating decision maker (“CODM”). The Company’s CODM is its principal executive officer, who decides how to allocate resources and assess performance. A single management team reports to the CODM, who manages the entire business. The Company’s CODM reviews consolidated statements of operations to make decisions, allocate resources and assess performance, and the CODM does not evaluate the profit or loss from any separate geography or product line. Concentrations The following table presents customers individually accounting for more than 10% of the Company’s net sales: For the Three Months Ended March 31, 2022 2021 Customer A 15 % 15 % Customer B ** 20 % The following table presents customers individually accounting for more than 10% of the Company’s accounts receivable: As of March 31, 2022 As of December 31, 2021 Customer A 22 % 24 % The following table presents suppliers individually accounting for more than 10% of the Company’s purchases: For the Three Months Ended March 31, 2022 2021 Supplier A 12 % 10 % Supplier B ** 14 % ** Less than 10% of the total Use of Estimates The preparation of consolidated financial statements in conformity with U.S. GAAP requires that management make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenue and expenses during the reporting period. Significant estimates and assumptions include the valuation of allowances for uncollectible receivables, inventory reserves, warranty reserves, stock-based compensation, evaluation of goodwill, other intangibles, property, plant and equipment for impairment, and determination of useful lives of long-lived assets. Actual results could materially differ from those estimates. Research and Development R&D expenses are expensed when incurred. R&D expenses consist primarily of wages, materials, testing and consulting related to the development of new engines, parts and applications. These costs were $4.6 million and $6.0 million for the three months ended March 31, 2022 and 2021, respectively. Restricted Cash The Company is required to maintain minimum levels of cash collateral to support the letters of credit. The cash collateral is held in a separate bank account which the Company is restricted from accessing. As discussed in Note 9. Commitments and Contingencies , the Company had outstanding letters of credi t of $2.1 million March 31, 2022 and December 31, 2021, and restricted cash of $3.2 million and $3.5 million related to the letters of credit at March 31, 2022 and December 31, 2021, respectively . As of March 31, 2022, the Company had restricted cash of $0.7 million related to a customer agreement executed in July 2021. The restricted cash is held in an escrow account and could be required to be refunded to the customer if conditions occur as defined in the agreement with the customer. The Company has not recognized revenue associated with the restricted cash and has recorded a liability in March 2022 within Noncurrent Contract Liabilities on the Consolidated Balance Sheet of $1.2 million. Inventories The Company’s inventories consist primarily of engines and parts. Engines are valued at the lower of cost plus estimated freight-in or net realizable value. Parts are valued at the lower of cost or net realizable value. Net realizable value approximates replacement cost. Cost is principally determined using the first-in, first-out method and includes material, labor and manufacturing overhead. It is the Company’s policy to review inventories on a continuing basis for obsolete, excess and slow-moving items and to record valuation adjustments for such items in order to eliminate non-recoverable costs from inventory. Valuation adjustments are recorded in an inventory reserve account and reduce the cost basis of the inventory in the period in which the reduced valuation is determined. Inventory reserves are established based on quantities on hand, usage and sales history, customer orders, projected demand and utilization within a current or future power system. Specific analysis of individual items or groups of items is performed based on these same criteria, as well as on changes in market conditions or any other identified conditions. Inventories consisted of the following: (in thousands) Inventories As of March 31, 2022 As of December 31, 2021 Raw materials $ 117,692 $ 120,130 Work in process 4,967 8,923 Finished goods 19,776 16,509 Total inventories 142,435 145,562 Inventory allowance (3,374) (3,370) Inventories, net $ 139,061 $ 142,192 Activity in the Company’s inventory allowance was as follows: (in thousands) For the Three Months Ended March 31, Inventory Allowance 2022 2021 Balance at beginning of period $ 3,370 $ 3,328 Charged to expense 49 553 Write-offs (45) (173) Balance at end of period $ 3,374 $ 3,708 Other Accrued Liabilities Other accrued liabilities consisted of the following: (in thousands) Other Accrued Liabilities As of March 31, 2022 As of December 31, 2021 Accrued product warranty $ 15,451 $ 15,830 Litigation reserves * 1,165 894 Contract liabilities 2,702 1,819 Accrued compensation and benefits 4,793 4,397 Operating lease liabilities 4,049 3,978 Accrued interest expense 1,247 625 Other 7,094 7,258 Total $ 36,501 $ 34,801 * As of March 31, 2022 and December 31, 2021 liti gation reserves related to various ongoing legal matters including associated legal fees. Warranty Costs The Company offers a standard limited warranty on the workmanship of its products that in most cases covers defects for a defined period. Warranties for certified emission products are mandated by the U.S. Environmental Protection Agency (the “EPA”) and/or the California Air Resources Board (the “CARB”) and are longer than the Company’s standard warranty on certain emission related products. The Company’s products also carry limited warranties from suppliers. The Company’s warranties generally apply to engines fully manufactured by the Company and to the modifications the Company makes to supplier base products. Costs related to supplier warranty claims are generally borne by the supplier and passed through to the end customer. Warranty estimates are based on historical experience and represent the projected cost associated with the product. A liability and related expense are recognized at the time products are sold. The Company adjusts estimates when it is determined that actual costs may differ from initial or previous estimates. The Company’s warranty liability is generally affected by failure rates, repair costs, and the timing of failures. Future events and circumstances related to these factors could materially change the estimates and require adjustments to the warranty liability. In addition, new product launches require a greater use of judgment in developing estimates until historical experience becomes available. Accrued product warranty activities are presented below: (in thousands) For the Three Months Ended March 31, Accrued Product Warranty 2022 2021 Balance at beginning of period $ 32,947 $ 31,542 Current year provision * 2,433 4,630 Changes in estimates for preexisting warranties ** (1,415) 4,119 Payments made during the period (6,120) (5,166) Balance at end of period 27,845 35,125 Less: current portion 15,451 17,073 Noncurrent accrued product warranty $ 12,394 $ 18,052 * Warranty (benefit)/costs, net of supplier recoveries, were a benefit of $0.3 million and a cost of $6.8 million for the three months ended March 31, 2022 and 2021, respectively. Supplier recoveries were $1.3 million and $1.9 million for the three months ended March 31, 2022 and 2021, respectively. ** Changes in estimates for preexisting warranties reflect changes in the Company’s estimate of warranty costs for products sold in prior periods. Such adjustments typically occur when claims experience deviates from historical and expected trends. During the three months ended March 31, 2022, the benefit was in part attributable to a contract revision. The Company recorded a benefit for changes in estimates of preexisting warranties of $1.4 million, or $0.06 per diluted share, for the three months ended March 31, 2022, and charges of $4.1 million, or $0.18 per diluted share, for the three months ended March 31, 2021. Recently Issued Accounting Pronouncements – Adopted In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of Effects of Reference Rate Reform on Financial Reporting , which provided optional guidance for a limited period of time to ease the potential burden in accounting for (or recognizing the effects of) reference rate reform on financial reporting. The amendment allows entities to elect not to apply certain modification accounting requirements to contracts affected by reference rate reform if certain criteria are met. An entity that makes this election would not have to remeasure the contracts at the modification date or reassess a previous accounting determination. Entities can elect various optional expedients that would allow them to continue applying hedge accounting for hedging relationships affected by reference rate reform, if certain criteria are met. The guidance was effective upon issuance and expires after December 31, 2022. There was no impact on the Company’s Consolidated Balance Sheets, Statements of Operations, Statements of Cash Flows or Statement of Stockholders’ (Deficit) Equity as a result of this guidance. The Company continues to monitor contracts potentially impacted by reference rate reform, including the Company’s debt agreements, and will continue to assess the potential impacts of this guidance as reference rates are updated. Recently Issued Accounting Pronouncements – Not Yet Adopted In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses: Measurement of Credit Losses on Financial Instruments, which applies primarily to the Company’s accounts receivable impairment loss allowances. The guidance provides a revised model whereby the current expected credit losses are used to compute impairment of financial instruments. The new model requires evaluation of historical experience and various current and expected factors, which may affect the estimated amount of losses and requires determination of whether the affected financial instruments should be grouped in units of account. The guidance, as originally issued, was effective for fiscal years beginning after December 15, 2019. In November 2019, the FASB issued ASU 2019-10, Financial Instruments – Credit Losses (Topic 326), Derivatives and Hedging (Topic 815), and Leases (Topic 842) Effective Dates , which deferred the effective dates of these standards for certain entities. Based on the guidance, the effective date of ASU 2016-13 is deferred for the Company until fiscal year 2023. The Company currently plans to adopt the guidance on January 1, 2023 when it becomes effective. The Company is continuing to assess the impact of the standard on its consolidated financial statements.

Revenue

Revenue	3 Months Ended
	Mar. 31, 2022
Revenue from Contract with Customer [Abstract]
Revenue	Revenue Disaggregation of Revenue The following table summarizes net sales by end market: (in thousands) For the Three Months Ended March 31, End Market 2022 2021 Power Systems $ 38,230 $ 25,159 Industrial 45,803 34,320 Transportation 14,914 40,692 Total $ 98,947 $ 100,171 The following table summarizes net sales by geographic area: (in thousands) For the Three Months Ended March 31, Geographic Area 2022 2021 United States $ 74,410 $ 89,595 North America (outside of United States) 3,411 2,320 Pacific Rim 13,841 5,528 Europe 3,122 1,610 Other 4,163 1,118 Total $ 98,947 $ 100,171 Contract Balances Most of the Company’s contracts are for a period of less than one year; however, certain long-term manufacturing and extended warranty contracts extend beyond one year. The timing of revenue recognition may differ from the time of invoicing to customers and these timing differences result in contract assets, or contract liabilities, on the Company’s Consolidated Balance Sheet. Contract assets include amounts related to the contractual right to consideration for completed performance when the right to consideration is conditional. The Company records contract liabilities when cash payments are received or due in advance of performance. Contract assets and contract liabilities are recognized at the contract level. (in thousands) As of March 31, 2022 As of December 31, 2021 Short-term contract assets (included in Prepaid expenses and other current assets ) $ 2,372 $ 2,707 Short-term contract liabilities (included in Other accrued liabilities ) (2,702) (1,819) Long-term contract liabilities (included in Noncurrent contract liabilities ) (3,565) (3,330) Net contract liabilities $ (3,895) $ (2,442) During the three months ended March 31, 2022 and 2021, the Company recognized $0.4 million and $14.9 million, respectively, of revenue upon satisfaction of performance obligations related to amounts that were included in the net contract liabilities balan ce as of December 31, 2021 and 2020, respectively. The decrease in the contract asset during the three months ended March 31, 2022 is related to the Company’s right to consideration being conditional at the end of the period. The increase in the contract liabilities during the three months ended March 31, 2022 was primarily related to revenue deferred related to a storage agreement for completed engines. Remaining Performance Obligations For performance obligations that extend beyond one year, the Company had $5.7 million of remaining performance obligations as of March 31, 2022 primarily related to a long-term manufacturing contract with a customer and extended warranties. The Company expects to recognize revenue related to these remaining performance obligations of approximately $1.8 million in the remainder of 2022, $1.0 million in 2023, $1.0 million in 2024, $0.5 million in 2025, $0.2 million in 2026 and less than $1.2 million in 2027 and beyond.

Weichai Transactions

Weichai Transactions	3 Months Ended
	Mar. 31, 2022
Equity [Abstract]
Weichai Transactions	Weichai Transactions Weichai Shareholder’s Loan Agreements The Company is party to four shareholder’s loan agreements with Weichai, including the $130 million Amended First Shareholder’s Loan Agreement, the $25 million Amended Second Shareholder’s Loan Agreement, the $50 million Third Shareholder’s Loan Agreement, and the $30 million Fourth Shareholder’s Loan Agreement. See additional discussion of these debt agreements in Note 6. Debt. Weichai Collaboration Arrangement and Related Party Transactions The Company and Weichai executed a strategic collaboration agreement (the “Collaboration Agreement”) in March 2017, in order to achieve their respective strategic objectives and enhance the strategic cooperation alliance to share experiences, expertise and resources. Among other things, the Collaboration Agreement established a joint steering committee, permitted Weichai to second a limited number of certain technical, marketing, sales, procurement and finance personnel to work at the Company and established several collaborations related to stationary natural-gas applications and Weichai diesel engines. The Collaboration Agreement provided for the steering committee to create various sub-committees with operating roles and otherwise governs the treatment of intellectual property of parties prior to the collaboration and the intellectual property developed during the collaboration. The Collaboration Agreement is set to expire in March 2023. The Company evaluates whether an arrangement is a collaborative arrangement at its inception based on the facts and circumstances specific to the arrangement. The Company also reevaluates whether an arrangement qualifies or continues to qualify as a collaborative arrangement whenever there is a change in either the roles of the participants or the participants’ exposure to significant risks and rewards dependent on the ultimate commercial success of the endeavor. For those collaborative arrangements where it is determined that the Company is the principal participant, costs incurred, and revenue generated from third parties are recorded on a gross basis in the financial statements. For the three months ended March 31, 2022 and 2021, the Company’s sales to Weichai were immaterial in all periods. Purchases of inventory from Weichai were $4.3 million and $3.1 million for the three months ended March 31, 2022 and 2021 , respectively. As of March 31, 2022 and December 31, 2021 , the Company had immaterial receivables from Weichai and outstanding accounts payables to Weichai of $16.8 million and $12.5 million, respectively. In January 2022, PSI and Baudouin, a subsidiary of Weichai, entered into an international distribution and sales agreement which enables Baudouin to bring PSI’s power systems line of products into the European, Middle Eastern, and African markets. In addition to sales, Baudouin will manage service, support, warranty claims, and technical requests. Common and Treasury Stock The changes in shares of Common and Treasury Stock are as follows: (in thousands) Common Shares Issued Treasury Stock Shares Common Shares Outstanding Balance at December 31, 2021 23,117 191 22,926 Net shares issued for Stock awards — (1) 1 Balance as of March 31, 2022 23,117 190 22,927

Property, Plant and Equipment

Property, Plant and Equipment	3 Months Ended
	Mar. 31, 2022
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Property, Plant and EquipmentProperty, plant and equipment by type were as follows: (in thousands) As of March 31, 2022 As of December 31, 2021 Property, Plant and Equipment Leasehold improvements $ 7,107 $ 7,107 Machinery and equipment 44,382 44,358 Construction in progress 887 1,125 Total property, plant and equipment, at cost 52,376 52,590 Accumulated depreciation (36,391) (35,246) Property, plant and equipment, net $ 15,985 $ 17,344

Goodwill and Other Intangibles

Goodwill and Other Intangibles	3 Months Ended
	Mar. 31, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangibles	Goodwill and Other Intangibles Goodwill The carrying amount of goodwill at both March 31, 2022 and December 31, 2021 was $29.8 million. Accumulated impairment losses at both March 31, 2022 and December 31, 2021 were $11.6 million. Other Intangible Assets Components of intangible assets are as follows: (in thousands) As of March 31, 2022 Gross Carrying Value Accumulated Amortization Net Book Value Customer relationships $ 34,940 $ (28,017) $ 6,923 Developed technology 700 (695) 5 Trade names and trademarks 1,700 (1,385) 315 Total $ 37,340 $ (30,097) $ 7,243 (in thousands) As of December 31, 2021 Gross Carrying Value Accumulated Amortization Net Book Value Customer relationships $ 34,940 $ (27,514) $ 7,426 Developed technology 700 (680) 20 Trade names and trademarks 1,700 (1,362) 338 Total $ 37,340 $ (29,556) $ 7,784

Debt

Debt	3 Months Ended
	Mar. 31, 2022
Debt Disclosure [Abstract]
Debt	Debt The Company’s outstanding debt consisted of the following: (in thousands) As of March 31, 2022 As of December 31, 2021 Short-term financing: Revolving credit facility * $ 130,000 $ 130,000 Other short-term financing 40,000 25,000 Total Short-Term Debt $ 170,000 $ 155,000 Long-term debt: Unsecured senior notes $ 25,000 $ 25,000 Finance leases and other debt 809 890 Total long-term debt and finance leases 25,809 25,890 Less: Current maturities of long-term debt and finance leases 223 254 Long-term debt $ 25,586 $ 25,636 * Unamortized financing costs and deferred fees on the revolving credit facility are not presented in the above table as they are classified in Prepaid expenses and other current assets on the Consolidated Balance Sheet. Unamortized debt issuance costs, were $1.7 million and $0.8 million as of March 31, 2022 and December 31, 2021, respectively. Credit Agreement and Shareholders’ Loan Agreements On March 25, 2022, the Company amended and restated its $130.0 million uncommitted senior secured revolving credit agreement with Standard Chartered by entering into the Second Amended and Restated Credit Agreement. The Second Amended and Restated Credit Agreement extends the maturity date of loans outstanding under its previous credit facility to the earlier of March 24, 2023 or the demand of Standard Chartered. The Second Amended and Restated Credit Agreement is subject to customary events of default and covenants, including minimum consolidated EBITDA and Consolidated Interest Coverage Ratio covenants for the second and third quarters of 2022. Borrowings under the Second Amended and Restated Credit Agreement will incur interest at either the alternate base rate or the SOFR plus 2.95% per annum. The Second Amended and Restated Credit Agreement continues to be secured by substantially all of the Company’s assets and provides Standard Chartered the right to demand payment of any and all of the outstanding borrowings and other amounts owed under the Second Amended and Restated Credit Agreement at any point in time prior to the maturity date at Standard Chartered’s discretion. Furthermore, the Second Amended and Restated Credit Agreement grants Standard Chartered a power of attorney (POA) to submit a borrowing request to Weichai under the Amended First Shareholder’s Loan Agreement (see discussion below) if the Company did not submit a borrowing request to Weichai within five business days of receiving a request from Standard Chartered to submit said borrowing request. As of March 31, 2022, the Company had $130.0 million outstanding under the Second Amended and Restated Credit Agreement. In connection with the Second Amended and Restated Credit Agreement, on March 25, 2022, the Company also amended two of its shareholder’s loan agreements with Weichai, to among other things, extend the maturities thereof. The Amended First Shareholder’s Loan Agreement continues to provide the Company with a $130.0 million subordinated loan under which Weichai is obligated to advance funds solely for purposes of repaying outstanding borrowings under the Second Amended and Restated Credit Agreement if the Company is unable to pay such borrowings. The Amended Second Shareholder’s Loan Agreement continues to provide the Company with a $25.0 million subordinated loan at the discretion of Weichai. The maturity of the Amended First Shareholder’s Loan Agreement was extended to April 24, 2023 and the maturity of the Amended Second Shareholder’s Loan Agreement was extended to May 20, 2023. The Company has covenanted to secure any amounts borrowed under either of the agreements upon payment in full of all amounts outstanding under the Second Amended and Restated Credit Agreement. As of March 31, 2022, there were no borrowings under the Amended First Shareholder’s Loan Agreement and $25.0 million under the Amended Second Shareholder’s Loan Agreement. The Company is also party to the Third Shareholder’s Loan Agreement with Weichai, which was entered into on December 10, 2021. The Third Shareholder’s Loan Agreement provides the Company with a $50.0 million uncommitted facility that is subordinated to the Second Amended and Restated Credit Agreement and any borrowing requests made under the Third Shareholder’s Loan Agreement are subject to Weichai’s discretionary approval. Borrowings under the Third Shareholder’s Loan Agreement bear interest at LIBOR plus 4.50% and can be used for general corporate purposes, except for certain legal expenditures which require additional approval from Weichai. The Third Shareholder’s Loan Agreement expires on November 30, 2022, with any outstanding principal and accrued interest due upon maturity. As of March 31, 2022, the Company had $40.0 million outstanding under the Third Shareholder’s Loan Agreement. On April 20, 2022, the Company entered into the Fourth Shareholder’s Loan Agreement with Weichai. The Fourth Shareholder’s Loan Agreement, which matures on March 31, 2023, provides the Company with access to up to $30.0 million of credit at the discretion of Weichai to supplement the Company’s working capital. The Fourth Shareholder’s Loan Agreement is subordinated in all respects to the Second Amended and Restated Credit Agreement. Borrowings under the Amended First Shareholder’s Loan Agreement, the Amended Second Shareholder’s Loan Agreement and the Fourth Shareholder’s Loan Agreement will incur interest at the applicable SOFR, plus 4.65% per annum. Further, if the applicable term SOFR is negative, the interest rate per annum shall be deemed as 4.65% per annum. If the interest rate for any loan is lower than Weichai’s borrowing cost, the interest rate for such loan shall be equal to Weichai’s borrowing cost plus 1%. As of March 31, 2022, the Company’s total outstanding debt obligations under the Second Amended and Restated Credit Agreement, the Amended Second Shareholder’s Loan Agreement, the Third Shareholder’s Loan Agreement and for finance leases and other debt were $195.8 million in the aggregate, and its cash and cash equivalents were $2.3 million. See Note 6. Debt , for additional information. See Note 1. Summary of Significant Accounting Policies and Other Information for further discussion of t

Leases

Leases	3 Months Ended
	Mar. 31, 2022
Leases [Abstract]
Leases	Leases Leases The Company has obligations under lease arrangements primarily for facilities, equipment and vehicles. These leases have original lease periods expiring between April 2022 and July 2034 . For the three months ended March 31, 2022, the Company recorded lease expense of $1.6 million within Cost of sales , $0.1 million within Research, development, and engineering expenses , less than $0.1 million within Selling, general and administrative expenses and less than $0.1 million within Interest expense in the Consolidated Statements of Operations. For the three months ended March 31, 2021, the Company recorded lease expense of $1.5 million within Cost of sales , $0.1 million within Research, development and engineering expenses , less than $0.1 million within Selling, general and administrative expenses and less than $0.1 million within Interest expense in the Consolidated Statements of Operations. The following table summarizes the components of lease expense: (in thousands) For the Three Months Ended March 31, 2022 2021 Operating lease cost $ 1,179 $ 1,242 Finance lease cost Amortization of right-of-use (“ROU”) asset 48 52 Interest expense 6 10 Short-term lease cost 36 102 Variable lease cost 380 338 Sublease income $ (265) $ — Total lease cost $ 1,384 $ 1,744 The following table presents supplemental cash flow information related to leases: (in thousands) For the Three Months Ended March 31, 2022 2021 Cash paid for amounts included in the measurement of lease liabilities Operating cash flows paid for operating leases $ 1,221 $ 1,257 Operating cash flows paid for interest portion of finance leases 6 10 Financing cash flows paid for principal portion of finance leases 51 51 As of March 31, 2022 and December 31, 2021, the weighted-average remaining lease term for both periods was 5.8 years for operating leases and 3.4 years for finance leases, respectively. The weighted-average discount rate was 7.0% for operating leases as of both March 31, 2022 and December 31, 2021, and 6.6% and 6.5% for finance leases as of March 31, 2022 and December 31, 2021, respectively. The following table presents supplemental balance sheet information related to leases: (in thousands) March 31, 2022 December 31, 2021 Operating lease ROU assets, net 1 $ 12,613 $ 13,545 Operating lease liabilities, current 2 4,049 3,978 Operating lease liabilities, non-current 3 9,258 10,304 Total operating lease liabilities $ 13,307 $ 14,282 Finance lease ROU assets, net 1 $ 316 $ 364 Finance lease liabilities, current 2 119 147 Finance lease liabilities, non-current 3 238 260 Total finance lease liabilities $ 357 $ 407 1. Included in Other noncurrent assets for operating leases and Property, plant and equipment, net for finance leases on the Consolidated Balance Sheets. 2. Included in Other accrued liabilities for operating leases and Current maturities of long-term debt for finance leases on the Consolidated Balance Sheets. 3. Included in Other noncurrent liabilities for operating leases and Long-term debt, net of current maturities for finance leases on the Consolidated Balance Sheets. The following table presents maturity analysis of lease liabilities as of March 31, 2022: (in thousands) Operating Leases Finance Leases Nine months ending December 31, 2022 $ 3,637 $ 111 Year ending December 31, 2023 3,347 103 Year ending December 31, 2024 1,815 84 Year ending December 31, 2025 1,851 82 Year ending December 31, 2026 1,515 17 Thereafter 4,023 — Total undiscounted lease payments 16,188 397 Less: imputed interest 2,881 40 Total lease liabilities $ 13,307 $ 357
Leases	Leases Leases The Company has obligations under lease arrangements primarily for facilities, equipment and vehicles. These leases have original lease periods expiring between April 2022 and July 2034 . For the three months ended March 31, 2022, the Company recorded lease expense of $1.6 million within Cost of sales , $0.1 million within Research, development, and engineering expenses , less than $0.1 million within Selling, general and administrative expenses and less than $0.1 million within Interest expense in the Consolidated Statements of Operations. For the three months ended March 31, 2021, the Company recorded lease expense of $1.5 million within Cost of sales , $0.1 million within Research, development and engineering expenses , less than $0.1 million within Selling, general and administrative expenses and less than $0.1 million within Interest expense in the Consolidated Statements of Operations. The following table summarizes the components of lease expense: (in thousands) For the Three Months Ended March 31, 2022 2021 Operating lease cost $ 1,179 $ 1,242 Finance lease cost Amortization of right-of-use (“ROU”) asset 48 52 Interest expense 6 10 Short-term lease cost 36 102 Variable lease cost 380 338 Sublease income $ (265) $ — Total lease cost $ 1,384 $ 1,744 The following table presents supplemental cash flow information related to leases: (in thousands) For the Three Months Ended March 31, 2022 2021 Cash paid for amounts included in the measurement of lease liabilities Operating cash flows paid for operating leases $ 1,221 $ 1,257 Operating cash flows paid for interest portion of finance leases 6 10 Financing cash flows paid for principal portion of finance leases 51 51 As of March 31, 2022 and December 31, 2021, the weighted-average remaining lease term for both periods was 5.8 years for operating leases and 3.4 years for finance leases, respectively. The weighted-average discount rate was 7.0% for operating leases as of both March 31, 2022 and December 31, 2021, and 6.6% and 6.5% for finance leases as of March 31, 2022 and December 31, 2021, respectively. The following table presents supplemental balance sheet information related to leases: (in thousands) March 31, 2022 December 31, 2021 Operating lease ROU assets, net 1 $ 12,613 $ 13,545 Operating lease liabilities, current 2 4,049 3,978 Operating lease liabilities, non-current 3 9,258 10,304 Total operating lease liabilities $ 13,307 $ 14,282 Finance lease ROU assets, net 1 $ 316 $ 364 Finance lease liabilities, current 2 119 147 Finance lease liabilities, non-current 3 238 260 Total finance lease liabilities $ 357 $ 407 1. Included in Other noncurrent assets for operating leases and Property, plant and equipment, net for finance leases on the Consolidated Balance Sheets. 2. Included in Other accrued liabilities for operating leases and Current maturities of long-term debt for finance leases on the Consolidated Balance Sheets. 3. Included in Other noncurrent liabilities for operating leases and Long-term debt, net of current maturities for finance leases on the Consolidated Balance Sheets. The following table presents maturity analysis of lease liabilities as of March 31, 2022: (in thousands) Operating Leases Finance Leases Nine months ending December 31, 2022 $ 3,637 $ 111 Year ending December 31, 2023 3,347 103 Year ending December 31, 2024 1,815 84 Year ending December 31, 2025 1,851 82 Year ending December 31, 2026 1,515 17 Thereafter 4,023 — Total undiscounted lease payments 16,188 397 Less: imputed interest 2,881 40 Total lease liabilities $ 13,307 $ 357

Fair Value of Financial Instrum

Fair Value of Financial Instruments	3 Months Ended
	Mar. 31, 2022
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	Fair Value of Financial Instruments For assets and liabilities measured at fair value on a recurring and nonrecurring basis, a three-level hierarchy of measurements based upon observable and unobservable inputs is used to arrive at fair value. Observable inputs are developed based on market data obtained from independent sources, while unobservable inputs reflect the Company’s assumptions about valuation based on the best information available in the circumstances. Depending on the inputs, the Company classifies each fair-value measurement as follows: • Level 1 – based on quoted prices in active markets for identical assets or liabilities; • Level 2 – based on other significant observable inputs for the assets or liabilities through corroborations with market data at the measurement date; and • Level 3 – based on significant unobservable inputs that reflect management’s best estimate of what market participants would use to price the assets or liabilities at the measurement date. Financial Instruments Measured at Carrying Value Current Assets Cash and cash equivalents are measured at carrying value, which approximates fair value because of the short-term maturities of these instruments. Debt The Company measured its revolving credit facility and other short-term financing at original carrying value. Unamortized financing costs and deferred fees on the revolving credit facility are classified in Prepaid expenses and other current assets on the Consolidated Balance Sheet. The fair value of the revolving credit facility and other short-term financing approximated carrying value, as it consisted primarily of short-term variable rate loans. (in thousands) As of March 31, 2022 Carrying Value Fair Value Level 1 Level 2 Level 3 Revolving credit facility $ 130,000 $ — $ 130,000 $ — Other financing 65,000 — 65,000 — (in thousands) As of December 31, 2021 Carrying Value Fair Value Level 1 Level 2 Level 3 Revolving credit facility $ 130,000 $ — $ 130,000 $ — Other financing 50,000 — 50,000 —

Commitments and Contingencies

Commitments and Contingencies	3 Months Ended
	Mar. 31, 2022
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Legal Contingencies The legal matters discussed below and others could result in losses, including damages, fines, civil penalties and criminal charges, which could be substantial. The Company records accruals for these contingencies to the extent the Company concludes that a loss is both probable and reasonably estimable. Regarding the matters disclosed below, unless otherwise disclosed, the Company has determined that liabilities associated with these legal matters are reasonably possible; however, unless otherwise stated, the possible loss or range of possible loss cannot be reasonably estimated. Given the nature of the litigation and investigations and the complexities involved, the Company is unable to reasonably estimate a possible loss for all such matters until the Company knows, among other factors the following: • what claims, if any, will survive dispositive motion practice; • the extent of the claims, particularly when damages are not specified or are indeterminate; • how the discovery process will affect the litigation; • the settlement posture of the other parties to the litigation; and • any other factors that may have a material effect on the litigation or investigation. However, the Company could incur judgments, enter into settlements or revise its expectations regarding the outcome of certain matters, and such developments could have a material adverse effect on the Company’s results of operations in the period in which the amounts are accrued and/or liquidity in the period in which the amounts are paid. Securities and Exchange Commission and United States Attorney’s Office for the Northern District of Illinois Investigations In September 2020, the Company entered into agreements with the SEC and the USAO to resolve the investigations into the Company’s past revenue recognition practices. Under the settled administrative order with the SEC, the Company committed to remediate the deficiencies in its internal control over financial reporting that constituted material weaknesses identified in its 2017 Form 10-K filed in May 2019 by April 30, 2021 unless an extension was provided by the SEC. On April 12, 2021, the SEC granted the Company’s request for an extension of time until March 31, 2022 in which to comply with the requirements of the administrative order to remediate the remaining outstanding material weaknesses. In April 2022, the SEC granted a further extension of time until March 31, 2023 to fully comply with the administrative order. To the extent that the Company’s request for an extension from the SEC, or other actions are not successful and completed in accordance with the provisions of the settlement with the SEC and USAO, the Company may be required to incur additional time and expense towards further remediation efforts and incremental substantive procedures, which could have a material adverse effect on its results of operations. In addition, failure to comply with the provisions of the settlement agreements with the SEC and USAO could result in further actions by one or both governmental agencies which could have a material adverse effect on the Company’s results of operations. Jerome Treadwell v. the Company In October 2018, a putative class-action complaint was filed against the Company and NOVAtime Technology, Inc. (“NOVAtime”) in the Circuit Court of Cook County, Illinois. In December 2018, NOVAtime removed the case to the U.S. District Court for the Northern District of Illinois, Eastern Division under the Class Action Fairness Act. Plaintiff has since voluntarily dismissed NOVAtime from the lawsuit without prejudice and filed an amended complaint in April 2019. The operative, amended complaint asserts violations of the Illinois Biometric Information Privacy Act (“BIPA”) in connection with employees’ use of the time clock to clock in and clock out using a finger scan and seeks statutory damages, attorneys’ fees, and injunctive and equitable relief. An aggrieved party under BIPA may recover (i) $1,000 per violation if the Company is found to have negligently violated BIPA or (ii) $5,000 per violation if the Company is found to have intentionally or recklessly violated BIPA plus reasonable attorneys’ fees. In May 2019, the Company filed its motion to dismiss the plaintiff’s amended complaint. In December 2019, the court denied the Company’s motion to dismiss. In January 2020, the Company moved for reconsideration of the court’s order denying the motion to dismiss, or in the alternative, to stay the case pending the Illinois Appellate Court’s ruling in McDonald v. Symphony Healthcare on a legal question that would be potentially dispositive in this matter. In February 2020, the court denied the Company’s motion for reconsideration, but required the parties to submit additional briefing on the Company’s motion to stay. In April 2020, the court granted the Company’s motion to stay and stayed the case pending the Illinois Appellate Court’s ruling in McDonald v. Symphony Healthcare . In October 2020, after the McDonald ruling, the court granted the parties’ joint request to continue the stay of the case f or 60 days. T he court also ordered the parties to schedule a settlement conference with the Magistrate Judge in May 2021 which went forward without a settlement being reached. The stay remains in place pending further guidance from the Court. As of March 31, 2022 and December 31, 2021, the Company had recorded an estimated liabili ty of $1.0 million and $0.3 million, respectively , recorded within Other accrued liabilities on the Consolidated Balance Sheet related to the settlement of this matter, related t o the potential settlement of this matter. Mast Powertrain v. the Company In February 2020, the Company received a demand for arbitration from Mast Powertrain, LLC (“Mast”) pursuant to a development agreement entered into in November 2011 (the “Development Agreement”). Mast claimed that it is owed more than $9.0 million in past royalties and other damages for products sold by the Company pursuant to the Development Agreement. The Company disputed Mast’s damages, denied that any royalties are owed to Mast, denied any liability, and counterclaimed for overpayment on invoices paid to Mast. Mast subsequently clarified its claim for past royalties owed to be approximately $4.5 million . In July 2021, the Company reached a settlement with Mast to resolve past claims for royalties owed for $1.5 million which the Company had previously recorded within Selling, general and administrative expenses in the Statement of Operations for the year-ended December 31, 2020 . The Company fully paid the settlement and had no recognized liability as of March 31, 2022 and $0.5 million was outstanding as of December 31, 2021. Other accrued liabilities on the Consolidated Balance Sheet related to the settlement of this matter. In addition, the Company entered into an agreement with Mast under which Mast will provide various technical services. Gary Winemaster Litigation v. The Company In August 2021, the Company’s former Chairman of the Board and former Chief Executive Officer and President, Gary Winemaster (“Winemaster”) filed suit in the Court of Chancery of the State of Delaware against the Company and Travelers Casualty and Surety Company of America (“Travelers”) alleging the Company’s breach of its advancement obligations under Winemaster’s indemnification agreement and Travelers’ breach of the side A policy between Traveler’s and the Company of which Winemaster is a beneficiary. In his complaint, Winemaster is seeking reimbursement under his indemnification agreement in excess of $7.2 million of attorney’s fees plus interest incurred by Winemaster in his defense of the Department of Justice (“DOJ”) case, U.S. v. Winemaster et al. . Since the filing of the complaint, Travelers has paid approximately $7.5 million to Winemaster’s attorneys, Latham and Watkins, under the Company’s side A policy to settle existing outstanding attorney’s fees. The Company expects Travelers to seek reimbursement from it for those costs pursuant to the terms of the side A policy. In October 2021, the Company and Gary Winemaster entered into a Stipulation and Advancement Order to handle all future attorney’s fees relating to his DOJ case and his pending SEC case, SEC v. Winemaster et al. to the extent not reimbursed by Travelers under the side A policy. Jeffrey Ehlers and Rick Lulloff Litigation In September 2021, Jeffrey Ehlers and Rick Lulloff (“Lulloff”), former employees of the Company, made demand against the Company for approximately $2.4 million and $1.2 million , respectively, for alleged wages due and owing under each employee’s employment contract related to “Incentive Bonuses” for revenues generated in the Company’s transportation end market. In November 2021, Lulloff and Ehlers separately filed complaints against the Company in the Circuit Court of Cook County, Illinois, alleging breach of contract and violations of the Illinois Wage and Payment Collection Act incorporating their claims in the above referenced demand letter. The Company filed a notice of removal from the Circuit Court of Cook County, Illinois and have also moved to consolidate the cases which has been granted by the Court. Given the preliminary stage of the matter, the Company cannot predict the outcome of this matter, the reasonable possibility or range of loss, or meaningfully quantify how the final resolution of this matter may impact its results of operations, financial condition or cash flow and therefore no accrual has been made as of March 31, 2022. Indemnification Agreements Under the Company’s bylaws and certain indemnification agreements, the Company has obligations to indemnify current and former officers and directors and certain current and former employees. As a result of cumulative legal fees and settlements previously paid, the Company fully exhausted its primary directors’ and officers’ insurance coverage of $30.0 million during the first quarter of 2020. Additional expenses currently expected to be incurred and that will occur in the future and/or liabilities that may be imposed in connection with actions against certain of the Company’s past directors and officers and certain former employees who are entitled to indemnification will be funded by the Company with its existing cash resources. The Company accrues for such costs as incurred within Selling, general and administrative expenses in the Company’s Consolidated Statements of Operations. For the three months ended March 31, 2022 and 2021, the Company incurred $0.2 million and $3.2 million, respectively, of costs related to these indemnification obligations. Included in the total indemnification obligations incurred for the three months ended March 31, 2022 are no costs that the Company incurred on behalf of Gary Winemaster, former Chairman of the Board and former Chief Executive Officer and President, who is also a related party. In June 2020, the Company entered into a new directors’ and officers’ liability insurance policy, which was renewed in June 2021. The insurance policy includes standard exclusions including for any ongoing or pending litigation such as the previously disclosed investigations by the SEC and USAO. Other Commitments At March 31, 2022, the Company had five outstanding letters of credit totaling $2.1 million. The letters of credit primarily serve as collateral for the Company for certain facility leases and insurance policies. As discussed in Note 1. Summary of Significant Accounting Policies and Other Information , the Company had restricted cash of $3.2 million as of March 31, 2022 related to these letters of credit. The Company has arrangements with a certain supplier that requires it to purchase minimum volumes or be subject to monetary penalties. As of March 31, 2022, if the Company were to stop purchasing from this supplier, the aggregate amount of the penalty would be approximately $6.9 million . The Company does not currently anticipate any material penalties under this contract based on ongoing contractual discussions with the supplier.

Income Taxes

Income Taxes	3 Months Ended
	Mar. 31, 2022
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes On a quarterly basis, the Company computes an estimated annual effective tax rate considering ordinary income and related income tax expense. Ordinary income refers to income (loss) before income tax expense excluding significant, unusual or infrequently occurring items. The tax effect of an unusual or infrequently occurring item is recorded in the interim period in which it occurs. The Company has assessed the need to maintain a valuation allowance for deferred tax assets based on an assessment of whether it is more likely than not that deferred tax benefits will be realized through the generation of future taxable income. Appropriate consideration is given to all available evidence, both positive and negative, in assessing the need for a valuation allowance. In assessing the realizability of the Company’s deferred tax assets, the Company considered whether it is more likely than not that some or all of the deferred tax assets will be realized through the generation of future taxable income. In making this determination, the Company assessed all of the evidence available at the time, including recent earnings, forecasted income projections and historical performance. The Company determined that the negative evidence outweighed the objectively verifiable positive evidence and continues to maintain a full valuation allowance against deferred tax assets. The effective tax rate for the three months ended March 31, 2022 was -17.4%, compared to an effective tax rate for the three months ended March 31, 2021 of -2.2%. The effective tax rates for all periods were significantly different than the applicable U.S. statutory tax rate . For the three months ended March 31, 2022 and March 31, 2021

Stockholders' Equity

Stockholders' Equity	3 Months Ended
	Mar. 31, 2022
Equity [Abstract]
Stockholders' Equity	Weichai Transactions Weichai Shareholder’s Loan Agreements The Company is party to four shareholder’s loan agreements with Weichai, including the $130 million Amended First Shareholder’s Loan Agreement, the $25 million Amended Second Shareholder’s Loan Agreement, the $50 million Third Shareholder’s Loan Agreement, and the $30 million Fourth Shareholder’s Loan Agreement. See additional discussion of these debt agreements in Note 6. Debt. Weichai Collaboration Arrangement and Related Party Transactions The Company and Weichai executed a strategic collaboration agreement (the “Collaboration Agreement”) in March 2017, in order to achieve their respective strategic objectives and enhance the strategic cooperation alliance to share experiences, expertise and resources. Among other things, the Collaboration Agreement established a joint steering committee, permitted Weichai to second a limited number of certain technical, marketing, sales, procurement and finance personnel to work at the Company and established several collaborations related to stationary natural-gas applications and Weichai diesel engines. The Collaboration Agreement provided for the steering committee to create various sub-committees with operating roles and otherwise governs the treatment of intellectual property of parties prior to the collaboration and the intellectual property developed during the collaboration. The Collaboration Agreement is set to expire in March 2023. The Company evaluates whether an arrangement is a collaborative arrangement at its inception based on the facts and circumstances specific to the arrangement. The Company also reevaluates whether an arrangement qualifies or continues to qualify as a collaborative arrangement whenever there is a change in either the roles of the participants or the participants’ exposure to significant risks and rewards dependent on the ultimate commercial success of the endeavor. For those collaborative arrangements where it is determined that the Company is the principal participant, costs incurred, and revenue generated from third parties are recorded on a gross basis in the financial statements. For the three months ended March 31, 2022 and 2021, the Company’s sales to Weichai were immaterial in all periods. Purchases of inventory from Weichai were $4.3 million and $3.1 million for the three months ended March 31, 2022 and 2021 , respectively. As of March 31, 2022 and December 31, 2021 , the Company had immaterial receivables from Weichai and outstanding accounts payables to Weichai of $16.8 million and $12.5 million, respectively. In January 2022, PSI and Baudouin, a subsidiary of Weichai, entered into an international distribution and sales agreement which enables Baudouin to bring PSI’s power systems line of products into the European, Middle Eastern, and African markets. In addition to sales, Baudouin will manage service, support, warranty claims, and technical requests. Common and Treasury Stock The changes in shares of Common and Treasury Stock are as follows: (in thousands) Common Shares Issued Treasury Stock Shares Common Shares Outstanding Balance at December 31, 2021 23,117 191 22,926 Net shares issued for Stock awards — (1) 1 Balance as of March 31, 2022 23,117 190 22,927

Loss Per Share

Loss Per Share	3 Months Ended
	Mar. 31, 2022
Earnings Per Share [Abstract]
Loss Per Share	Loss Per Share The Company computes basic loss per share by dividing net loss by the weighted-average common shares outstanding during the year. Diluted loss per share is calculated to give effect to all potentially dilutive common shares that were outstanding during the year. Weighted-average diluted common shares outstanding primarily reflect the additional shares that would be issued upon the assumed exercise of stock options and the assumed vesting of unvested share awards. The treasury stock method has been used to compute diluted loss per share for the three months ended March 31, 2022 and 2021. The Company issued Stock Appreciation Rights (“SARs”) and Restricted Stock Awards (“RSAs”), all of which have been evaluated for their potentially dilutive effect under the treasury stock method. See Note 13. Stock-Based Compensation in the Company’s 2021 Annual Report for additional information on the SARs and the RSAs. The computations of basic and diluted loss per share are as follows: (in thousands, except per share basis) For the Three Months Ended March 31, 2022 2021 Numerator: Net loss $ (2,599) $ (18,150) Denominator: Shares used in computing net loss per share: Weighted-average common shares outstanding – basic 22,927 22,892 Effect of dilutive securities — — Weighted-average common shares outstanding – diluted 22,927 22,892 Loss per common share: Loss per share of common stock – basic $ (0.11) $ (0.79) Loss per share of common stock – diluted $ (0.11) $ (0.79) The aggregate number of shares excluded from the diluted loss per share calculations, because they would have been anti-diluti ve, were 0.2 million for the three months ended March 31, 2022 and 2021. For the three months ended March 31, 2022 and 2021, SARs and RSAs were not included in the diluted loss per share calculations as they would have been anti-dilutive (1) due to the losses reported in the Consolidated Statements of Operations or (2) the Company’s average stock price was less than the exercise price of the SARs or the grant price of the RSAs.

Related Party Transactions

Related Party Transactions	3 Months Ended
	Mar. 31, 2022
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions Weichai Transactions See Note 3. Weichai Transactions for information regarding the Amended First Shareholder’s Loan Agreement, the Amended Second Shareholder’s Loan Agreement, the Third Shareholder’s Loan Agreement, the Fourth Shareholder’s Loan Agreement and the Collaboration Agreement with Weichai . Transactions with Joint Ventures MAT-PSI Holdings, LLC In December 2012, the Company and MAT Holdings, Inc. (“MAT”) entered into an agreement to create MAT-PSI Holdings, LLC (“MAT-PSI”), which was intended to be a holding company of its 100% Chinese wholly-owned foreign entity, referred to as Green Power. The Company invested $0.9 million for its 50% share of MAT-PSI, which was formed to manufacture, assemble and supply natural gas, gas and alternative-fueled power systems to Chinese and Asian forklift customers. The venture established a production facility in Dalian and also sourced base engines from a local Chinese factory. As MAT-PSI was not profitable, the venture was closed in 2017; however, the Company had previously been in dispute with Green Power related to the wind up of the joint venture and outstanding receivables. On March 29, 2021, the Company executed a settlement agreement with MAT and Green Power which resolved the dispute. The final settlement agreement did not have a material impact on the Company’s consolidated financial statements. Doosan-PSI, LLC In 2015, the Company and Doosan Infracore Co., Ltd. (“Doosan”), a subsidiary of Doosan Group, entered into an agreement to form Doosan-PSI, LLC. The Company invested $1.0 million to acquire 50% of the venture, which was formed to operate in the field of developing, designing, testing, manufacturing, assembling, branding, marketing, selling, distributing and providing support for industrial gas engines and all components and materials required for assembly of the gas engines to the global power generation market outside of North America and South Korea. In the fourth quarter of 2019, Doosan and the Company agreed to wind down and dissolve the joint venture. In the second quarter of 2021, the Company received a cash distribution from the joint ventu re of $2.2 million as a resul t of the final wind down and dissolution of the joint venture. Other Related Party Transactions See Note 9. Commitments and Contingencies for information regarding the Company’s indemnification obligations related to certain former directors and officers of the Company.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies and Other Information (Policies)	3 Months Ended
	Mar. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Consolidation	The consolidated financial statements include the accounts of Power Solutions International, Inc. and its wholly-owned subsidiaries and majority-owned subsidiaries in which the Company exercises control. The foregoing financial information was prepared in accordance with generally accepted accounting principles in the United States (“U.S. GAAP”) and rules and regulations of the SEC for interim financial reporting. All intercompany balances and transactions have been eliminated in consolidation.
Basis of Presentation	Certain information and note disclosures normally included in the Company’s annual financial statements prepared in accordance with U.S. GAAP have been condensed or omitted. The accompanying consolidated financial statements should be read in conjunction with, and have been prepared in accordance with accounting policies reflected in, the consolidated financial statements and related notes, included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2021 (“the 2021 Annual Report”). The Company’s significant accounting policies are described in the aforementioned 2021 Annual Report. Included below are certain updates to those policies. The accompanying interim financial information is unaudited; however, the Company believes the financial information reflects all adjustments (consisting of items of a normal recurring nature) necessary for a fair presentation of financial position, results of operations and cash flows in conformity with U.S. GAAP. Operating results for interim periods are not necessarily indicative of annual operating results.
Use of Estimates	The preparation of consolidated financial statements in conformity with U.S. GAAP requires that management make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenue and expenses during the reporting period. Significant estimates and assumptions include the valuation of allowances for uncollectible receivables, inventory reserves, warranty reserves, stock-based compensation, evaluation of goodwill, other intangibles, property, plant and equipment for impairment, and determination of useful lives of long-lived assets. Actual results could materially differ from those estimates.
Research and Development	R&D expenses are expensed when incurred. R&D expenses consist primarily of wages, materials, testing and consulting related to the development of new engines, parts and applications.
Restricted Cash	The Company is required to maintain minimum levels of cash collateral to support the letters of credit. The cash collateral is held in a separate bank account which the Company is restricted from accessing.
Inventories	The Company’s inventories consist primarily of engines and parts. Engines are valued at the lower of cost plus estimated freight-in or net realizable value. Parts are valued at the lower of cost or net realizable value. Net realizable value approximates replacement cost. Cost is principally determined using the first-in, first-out method and includes material, labor and manufacturing overhead. It is the Company’s policy to review inventories on a continuing basis for obsolete, excess and slow-moving items and to record valuation adjustments for such items in order to eliminate non-recoverable costs from inventory. Valuation adjustments are recorded in an inventory reserve account and reduce the cost basis of the inventory in the period in which the reduced valuation is determined. Inventory reserves are established based on quantities on hand, usage and sales history, customer orders, projected demand and utilization within a current or future power system. Specific analysis of individual items or groups of items is performed based on these same criteria, as well as on changes in market conditions or any other identified conditions.
Warranty Costs	The Company offers a standard limited warranty on the workmanship of its products that in most cases covers defects for a defined period. Warranties for certified emission products are mandated by the U.S. Environmental Protection Agency (the “EPA”) and/or the California Air Resources Board (the “CARB”) and are longer than the Company’s standard warranty on certain emission related products. The Company’s products also carry limited warranties from suppliers. The Company’s warranties generally apply to engines fully manufactured by the Company and to the modifications the Company makes to supplier base products. Costs related to supplier warranty claims are generally borne by the supplier and passed through to the end customer. Warranty estimates are based on historical experience and represent the projected cost associated with the product. A liability and related expense are recognized at the time products are sold. The Company adjusts estimates when it is determined that actual costs may differ from initial or previous estimates. The Company’s warranty liability is generally affected by failure rates, repair costs, and the timing of failures. Future events and circumstances related to these factors could materially change the estimates and require adjustments to the warranty liability. In addition, new product launches require a greater use of judgment in developing estimates until historical experience becomes available.
Recently Issued Accounting Pronouncements - Adopted and Not Yet Adopted	Recently Issued Accounting Pronouncements – Adopted In March 2020, the FASB issued ASU 2020-04, Reference Rate Reform (Topic 848): Facilitation of Effects of Reference Rate Reform on Financial Reporting , which provided optional guidance for a limited period of time to ease the potential burden in accounting for (or recognizing the effects of) reference rate reform on financial reporting. The amendment allows entities to elect not to apply certain modification accounting requirements to contracts affected by reference rate reform if certain criteria are met. An entity that makes this election would not have to remeasure the contracts at the modification date or reassess a previous accounting determination. Entities can elect various optional expedients that would allow them to continue applying hedge accounting for hedging relationships affected by reference rate reform, if certain criteria are met. The guidance was effective upon issuance and expires after December 31, 2022. There was no impact on the Company’s Consolidated Balance Sheets, Statements of Operations, Statements of Cash Flows or Statement of Stockholders’ (Deficit) Equity as a result of this guidance. The Company continues to monitor contracts potentially impacted by reference rate reform, including the Company’s debt agreements, and will continue to assess the potential impacts of this guidance as reference rates are updated. Recently Issued Accounting Pronouncements – Not Yet Adopted In June 2016, the FASB issued ASU 2016-13, Financial Instruments – Credit Losses: Measurement of Credit Losses on Financial Instruments, which applies primarily to the Company’s accounts receivable impairment loss allowances. The guidance provides a revised model whereby the current expected credit losses are used to compute impairment of financial instruments. The new model requires evaluation of historical experience and various current and expected factors, which may affect the estimated amount of losses and requires determination of whether the affected financial instruments should be grouped in units of account. The guidance, as originally issued, was effective for fiscal years beginning after December 15, 2019. In November 2019, the FASB issued ASU 2019-10, Financial Instruments – Credit Losses (Topic 326), Derivatives and Hedging (Topic 815), and Leases (Topic 842) Effective Dates , which deferred the effective dates of these standards for certain entities. Based on the guidance, the effective date of ASU 2016-13 is deferred for the Company until fiscal year 2023. The Company currently plans to adopt the guidance on January 1, 2023 when it becomes effective. The Company is continuing to assess the impact of the standard on its consolidated financial statements.
Revenue	Most of the Company’s contracts are for a period of less than one year; however, certain long-term manufacturing and extended warranty contracts extend beyond one year. The timing of revenue recognition may differ from the time of invoicing to customers and these timing differences result in contract assets, or contract liabilities, on the Company’s Consolidated Balance Sheet. Contract assets include amounts related to the contractual right to consideration for completed performance when the right to consideration is conditional. The Company records contract liabilities when cash payments are received or due in advance of performance. Contract assets and contract liabilities are recognized at the contract level.
Fair Value of Financial Instruments	Current Assets Cash and cash equivalents are measured at carrying value, which approximates fair value because of the short-term maturities of these instruments. Debt The Company measured its revolving credit facility and other short-term financing at original carrying value. Unamortized financing costs and deferred fees on the revolving credit facility are classified in Prepaid expenses and other current assets on the Consolidated Balance Sheet.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies and Other Information (Tables)	3 Months Ended
	Mar. 31, 2022
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedules of Concentration of Risk, by Risk Factor	The following table presents customers individually accounting for more than 10% of the Company’s net sales: For the Three Months Ended March 31, 2022 2021 Customer A 15 % 15 % Customer B ** 20 % The following table presents customers individually accounting for more than 10% of the Company’s accounts receivable: As of March 31, 2022 As of December 31, 2021 Customer A 22 % 24 % The following table presents suppliers individually accounting for more than 10% of the Company’s purchases: For the Three Months Ended March 31, 2022 2021 Supplier A 12 % 10 % Supplier B ** 14 % ** Less than 10% of the total
Schedule of Inventory, Current	Inventories consisted of the following: (in thousands) Inventories As of March 31, 2022 As of December 31, 2021 Raw materials $ 117,692 $ 120,130 Work in process 4,967 8,923 Finished goods 19,776 16,509 Total inventories 142,435 145,562 Inventory allowance (3,374) (3,370) Inventories, net $ 139,061 $ 142,192 Activity in the Company’s inventory allowance was as follows: (in thousands) For the Three Months Ended March 31, Inventory Allowance 2022 2021 Balance at beginning of period $ 3,370 $ 3,328 Charged to expense 49 553 Write-offs (45) (173) Balance at end of period $ 3,374 $ 3,708
Schedule of Other Accrued Liabilities	Other accrued liabilities consisted of the following: (in thousands) Other Accrued Liabilities As of March 31, 2022 As of December 31, 2021 Accrued product warranty $ 15,451 $ 15,830 Litigation reserves * 1,165 894 Contract liabilities 2,702 1,819 Accrued compensation and benefits 4,793 4,397 Operating lease liabilities 4,049 3,978 Accrued interest expense 1,247 625 Other 7,094 7,258 Total $ 36,501 $ 34,801 * As of March 31, 2022 and December 31, 2021 liti gation reserves related to various ongoing legal matters including associated legal fees.
Schedule of Accrued Product Warranty	Accrued product warranty activities are presented below: (in thousands) For the Three Months Ended March 31, Accrued Product Warranty 2022 2021 Balance at beginning of period $ 32,947 $ 31,542 Current year provision * 2,433 4,630 Changes in estimates for preexisting warranties ** (1,415) 4,119 Payments made during the period (6,120) (5,166) Balance at end of period 27,845 35,125 Less: current portion 15,451 17,073 Noncurrent accrued product warranty $ 12,394 $ 18,052 * Warranty (benefit)/costs, net of supplier recoveries, were a benefit of $0.3 million and a cost of $6.8 million for the three months ended March 31, 2022 and 2021, respectively. Supplier recoveries were $1.3 million and $1.9 million for the three months ended March 31, 2022 and 2021, respectively.

Revenue (Tables)

Revenue (Tables)	3 Months Ended
	Mar. 31, 2022
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue	The following table summarizes net sales by end market: (in thousands) For the Three Months Ended March 31, End Market 2022 2021 Power Systems $ 38,230 $ 25,159 Industrial 45,803 34,320 Transportation 14,914 40,692 Total $ 98,947 $ 100,171
Revenue from External Customers by Geographic Areas	The following table summarizes net sales by geographic area: (in thousands) For the Three Months Ended March 31, Geographic Area 2022 2021 United States $ 74,410 $ 89,595 North America (outside of United States) 3,411 2,320 Pacific Rim 13,841 5,528 Europe 3,122 1,610 Other 4,163 1,118 Total $ 98,947 $ 100,171
Schedule of Contract Balances	(in thousands) As of March 31, 2022 As of December 31, 2021 Short-term contract assets (included in Prepaid expenses and other current assets ) $ 2,372 $ 2,707 Short-term contract liabilities (included in Other accrued liabilities ) (2,702) (1,819) Long-term contract liabilities (included in Noncurrent contract liabilities ) (3,565) (3,330) Net contract liabilities $ (3,895) $ (2,442)

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	3 Months Ended
	Mar. 31, 2022
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	Property, plant and equipment by type were as follows: (in thousands) As of March 31, 2022 As of December 31, 2021 Property, Plant and Equipment Leasehold improvements $ 7,107 $ 7,107 Machinery and equipment 44,382 44,358 Construction in progress 887 1,125 Total property, plant and equipment, at cost 52,376 52,590 Accumulated depreciation (36,391) (35,246) Property, plant and equipment, net $ 15,985 $ 17,344

Goodwill and Other Intangibles

Goodwill and Other Intangibles (Tables)	3 Months Ended
	Mar. 31, 2022
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Finite-Lived Intangible Assets	Components of intangible assets are as follows: (in thousands) As of March 31, 2022 Gross Carrying Value Accumulated Amortization Net Book Value Customer relationships $ 34,940 $ (28,017) $ 6,923 Developed technology 700 (695) 5 Trade names and trademarks 1,700 (1,385) 315 Total $ 37,340 $ (30,097) $ 7,243 (in thousands) As of December 31, 2021 Gross Carrying Value Accumulated Amortization Net Book Value Customer relationships $ 34,940 $ (27,514) $ 7,426 Developed technology 700 (680) 20 Trade names and trademarks 1,700 (1,362) 338 Total $ 37,340 $ (29,556) $ 7,784

Debt (Tables)

Debt (Tables)	3 Months Ended
	Mar. 31, 2022
Debt Disclosure [Abstract]
Schedule of Debt	The Company’s outstanding debt consisted of the following: (in thousands) As of March 31, 2022 As of December 31, 2021 Short-term financing: Revolving credit facility * $ 130,000 $ 130,000 Other short-term financing 40,000 25,000 Total Short-Term Debt $ 170,000 $ 155,000 Long-term debt: Unsecured senior notes $ 25,000 $ 25,000 Finance leases and other debt 809 890 Total long-term debt and finance leases 25,809 25,890 Less: Current maturities of long-term debt and finance leases 223 254 Long-term debt $ 25,586 $ 25,636 * Unamortized financing costs and deferred fees on the revolving credit facility are not presented in the above table as they are classified in Prepaid expenses and other current assets on the Consolidated Balance Sheet. Unamortized debt issuance costs, were $1.7 million and $0.8 million as of March 31, 2022 and December 31, 2021, respectively.

Leases (Tables)

Leases (Tables)	3 Months Ended
	Mar. 31, 2022
Leases [Abstract]
Components of Lease Expense and Cash Flow Information	The following table summarizes the components of lease expense: (in thousands) For the Three Months Ended March 31, 2022 2021 Operating lease cost $ 1,179 $ 1,242 Finance lease cost Amortization of right-of-use (“ROU”) asset 48 52 Interest expense 6 10 Short-term lease cost 36 102 Variable lease cost 380 338 Sublease income $ (265) $ — Total lease cost $ 1,384 $ 1,744 The following table presents supplemental cash flow information related to leases: (in thousands) For the Three Months Ended March 31, 2022 2021 Cash paid for amounts included in the measurement of lease liabilities Operating cash flows paid for operating leases $ 1,221 $ 1,257 Operating cash flows paid for interest portion of finance leases 6 10 Financing cash flows paid for principal portion of finance leases 51 51
Supplemental Balance Sheet Information	The following table presents supplemental balance sheet information related to leases: (in thousands) March 31, 2022 December 31, 2021 Operating lease ROU assets, net 1 $ 12,613 $ 13,545 Operating lease liabilities, current 2 4,049 3,978 Operating lease liabilities, non-current 3 9,258 10,304 Total operating lease liabilities $ 13,307 $ 14,282 Finance lease ROU assets, net 1 $ 316 $ 364 Finance lease liabilities, current 2 119 147 Finance lease liabilities, non-current 3 238 260 Total finance lease liabilities $ 357 $ 407 1. Included in Other noncurrent assets for operating leases and Property, plant and equipment, net for finance leases on the Consolidated Balance Sheets. 2. Included in Other accrued liabilities for operating leases and Current maturities of long-term debt for finance leases on the Consolidated Balance Sheets. 3. Included in Other noncurrent liabilities for operating leases and Long-term debt, net of current maturities for finance leases on the Consolidated Balance Sheets.
Maturity Analysis of Operating Lease Liabilities	The following table presents maturity analysis of lease liabilities as of March 31, 2022: (in thousands) Operating Leases Finance Leases Nine months ending December 31, 2022 $ 3,637 $ 111 Year ending December 31, 2023 3,347 103 Year ending December 31, 2024 1,815 84 Year ending December 31, 2025 1,851 82 Year ending December 31, 2026 1,515 17 Thereafter 4,023 — Total undiscounted lease payments 16,188 397 Less: imputed interest 2,881 40 Total lease liabilities $ 13,307 $ 357
Maturity Analysis of Financing Lease Liabilities	The following table presents maturity analysis of lease liabilities as of March 31, 2022: (in thousands) Operating Leases Finance Leases Nine months ending December 31, 2022 $ 3,637 $ 111 Year ending December 31, 2023 3,347 103 Year ending December 31, 2024 1,815 84 Year ending December 31, 2025 1,851 82 Year ending December 31, 2026 1,515 17 Thereafter 4,023 — Total undiscounted lease payments 16,188 397 Less: imputed interest 2,881 40 Total lease liabilities $ 13,307 $ 357

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	3 Months Ended
	Mar. 31, 2022
Fair Value Disclosures [Abstract]
Schedule of Fair Value Measurements at Reporting Date	(in thousands) As of March 31, 2022 Carrying Value Fair Value Level 1 Level 2 Level 3 Revolving credit facility $ 130,000 $ — $ 130,000 $ — Other financing 65,000 — 65,000 — (in thousands) As of December 31, 2021 Carrying Value Fair Value Level 1 Level 2 Level 3 Revolving credit facility $ 130,000 $ — $ 130,000 $ — Other financing 50,000 — 50,000 —

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	3 Months Ended
	Mar. 31, 2022
Equity [Abstract]
Schedule of Common Stock Outstanding Roll Forward	The changes in shares of Common and Treasury Stock are as follows: (in thousands) Common Shares Issued Treasury Stock Shares Common Shares Outstanding Balance at December 31, 2021 23,117 191 22,926 Net shares issued for Stock awards — (1) 1 Balance as of March 31, 2022 23,117 190 22,927

Loss Per Share (Tables)

Loss Per Share (Tables)	3 Months Ended
	Mar. 31, 2022
Earnings Per Share [Abstract]
Schedule of Basic and Diluted Loss Per Share	The computations of basic and diluted loss per share are as follows: (in thousands, except per share basis) For the Three Months Ended March 31, 2022 2021 Numerator: Net loss $ (2,599) $ (18,150) Denominator: Shares used in computing net loss per share: Weighted-average common shares outstanding – basic 22,927 22,892 Effect of dilutive securities — — Weighted-average common shares outstanding – diluted 22,927 22,892 Loss per common share: Loss per share of common stock – basic $ (0.11) $ (0.79) Loss per share of common stock – diluted $ (0.11) $ (0.79)

Summary of Significant Accoun_4

Summary of Significant Accounting Policies and Other Information - Narrative (Details)	Apr. 20, 2022USD ($)	Mar. 25, 2022USD ($)dayagreement	Dec. 10, 2021USD ($)	Mar. 31, 2017USD ($)	Mar. 31, 2022USD ($)boardMembersegment$ / shares	Mar. 31, 2021USD ($)	Dec. 31, 2021USD ($)$ / shares	Apr. 30, 2019$ / shares
Concentration Risk [Line Items]
Common stock, par value (in dollars per share) | $ / shares					$ 0.001		$ 0.001	$ 0.001
Number of board members | boardMember					4
Short-term financing					$ 170,000,000		$ 155,000,000
Debt instrument, number of loan agreements amended | agreement		2
Debt, long-term and short-term, combined amount					195,800,000
Cash and cash equivalents					$ 2,267,000	$ 23,404,000	6,255,000
Number of operating segments | segment					1
Research and development and engineering expenses					$ 4,600,000	6,000,000
Outstanding letters of credit amount					2,100,000		2,100,000
Restricted cash					3,160,000	$ 3,299,000	3,477,000
Restricted cash recorded as liability					3,565,000		3,330,000
Revolving credit facility
Concentration Risk [Line Items]
Short-term financing					130,000,000		$ 130,000,000
Contract With Customer
Concentration Risk [Line Items]
Restricted cash					700,000
Restricted cash recorded as liability					1,200,000
Share Purchase Agreement, Weichai Transaction
Concentration Risk [Line Items]
Consideration received on transaction				$ 60,000,000
First, Second, And Fourth Shareholder's Loan Agreement, Weichai | Subsequent Event
Concentration Risk [Line Items]
Debt instrument, incremental borrowing cost	1.00%
First, Second, And Fourth Shareholder's Loan Agreement, Weichai | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate | Subsequent Event
Concentration Risk [Line Items]
Basis spread on variable rate	4.65%
First Shareholder's Loan Agreement, Weichai | Revolving credit facility
Concentration Risk [Line Items]
Short-term financing					0
Second Shareholder's Loan Agreement, Weichai | Revolving credit facility
Concentration Risk [Line Items]
Short-term financing					25,000,000
Third Shareholder's Loan Agreement, Weichai | Revolving credit facility
Concentration Risk [Line Items]
Short-term financing					40,000,000
Revolving credit facility | Second Standard Chartered Bank Credit Agreement
Concentration Risk [Line Items]
Maximum borrowing capacity		$ 130,000,000			130,000,000
Number of days to submit borrowing request | day		5
Short-term financing					130,000,000
Basis spread on variable rate		2.95%
Revolving credit facility | First Shareholder's Loan Agreement, Weichai
Concentration Risk [Line Items]
Maximum borrowing capacity		$ 130,000,000			130,000,000
Revolving credit facility | Second Shareholder's Loan Agreement, Weichai
Concentration Risk [Line Items]
Maximum borrowing capacity		$ 25,000,000			25,000,000
Revolving credit facility | Fourth Shareholder's Loan Agreement, Weichai
Concentration Risk [Line Items]
Maximum borrowing capacity					30,000,000
Revolving credit facility | Fourth Shareholder's Loan Agreement, Weichai | Subsequent Event
Concentration Risk [Line Items]
Maximum borrowing capacity	$ 30,000,000
Revolving credit facility | Third Shareholder's Loan Agreement, Weichai
Concentration Risk [Line Items]
Maximum borrowing capacity			$ 50,000,000		$ 50,000,000
Revolving credit facility | Third Shareholder's Loan Agreement, Weichai | LIBOR
Concentration Risk [Line Items]
Basis spread on variable rate			4.50%

Summary of Significant Accoun_5

Summary of Significant Accounting Policies and Other Information - Schedules of Concentration of Risk, by Risk Factor (Details)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Supplier Concentration Risk | Supplier A | Purchases
Concentration Risk [Line Items]
Concentration risk, percentage	12.00%	10.00%
Supplier Concentration Risk | Supplier B | Purchases
Concentration Risk [Line Items]
Concentration risk, percentage		14.00%
Customer A | Customer Concentration Risk | Net Sales
Concentration Risk [Line Items]
Concentration risk, percentage	15.00%	15.00%
Customer A | Customer Concentration Risk | Accounts Receivable
Concentration Risk [Line Items]
Concentration risk, percentage	22.00%	24.00%
Customer B | Customer Concentration Risk | Net Sales
Concentration Risk [Line Items]
Concentration risk, percentage		20.00%

Summary of Significant Accoun_6

Summary of Significant Accounting Policies and Other Information - Schedule of Inventory, Current (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Inventories
Raw materials	$ 117,692		$ 120,130
Work in process	4,967		8,923
Finished goods	19,776		16,509
Total inventories	142,435		145,562
Inventory allowance	(3,374)		(3,370)
Inventories, net	139,061		$ 142,192
Inventory Allowance
Balance at beginning of period	3,370	$ 3,328
Charged to expense	49	553
Write-offs	(45)	(173)
Balance at end of period	$ 3,374	$ 3,708

Summary of Significant Accoun_7

Summary of Significant Accounting Policies and Other Information - Schedule of Other Accrued Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Accrued product warranty	$ 15,451	$ 15,830	$ 17,073
Litigation reserves	1,165	894
Contract liabilities	2,702	1,819
Accrued compensation and benefits	4,793	4,397
Operating lease liabilities	4,049	3,978
Accrued interest expense	1,247	625
Other	7,094	7,258
Total	$ 36,501	$ 34,801

Summary of Significant Accoun_8

Summary of Significant Accounting Policies and Other Information - Schedule of Product Warranty Liability (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Accrued Product Warranty
Balance at beginning of period	$ 32,947	$ 31,542
Current year provision	2,433	4,630
Changes in estimates for preexisting warranties	(1,415)	4,119
Payments made during the period	(6,120)	(5,166)
Balance at end of period	27,845	35,125
Less: current portion	15,451	17,073	$ 15,830
Noncurrent accrued product warranty	12,394	18,052
Warranty (benefit)/costs, net of supplier recoveries	(300)	6,800
Supplier recoveries	$ 1,300	$ 1,900
Diluted share (in dollars per share)	$ (0.06)	$ 0.18

Revenue - Disaggregation of Rev

Revenue - Disaggregation of Revenue and Revenue from External Customers by Geographic Areas (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Disaggregation of Revenue [Line Items]
Total	$ 98,947	$ 100,171
United States
Disaggregation of Revenue [Line Items]
Total	74,410	89,595
North America (outside of United States)
Disaggregation of Revenue [Line Items]
Total	3,411	2,320
Pacific Rim
Disaggregation of Revenue [Line Items]
Total	13,841	5,528
Europe
Disaggregation of Revenue [Line Items]
Total	3,122	1,610
Other
Disaggregation of Revenue [Line Items]
Total	4,163	1,118
Power Systems
Disaggregation of Revenue [Line Items]
Total	38,230	25,159
Industrial
Disaggregation of Revenue [Line Items]
Total	45,803	34,320
Transportation
Disaggregation of Revenue [Line Items]
Total	$ 14,914	$ 40,692

Revenue - Schedule of Contract

Revenue - Schedule of Contract Balances (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Revenue from Contract with Customer [Abstract]
Short-term contract assets (included in Prepaid expenses and other current assets)	$ 2,372	$ 2,707
Short-term contract liabilities (included in Other accrued liabilities)	(2,702)	(1,819)
Long-term contract liabilities (included in Noncurrent contract liabilities)	(3,565)	(3,330)
Net contract liabilities	$ (3,895)	$ (2,442)

Revenue - Narrative (Details)

Revenue - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue recognized	$ 0.4	$ 14.9
Revenue, remaining performance obligation, amount	5.7
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 1.8
Revenue, remaining performance obligation, period	9 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 1
Revenue, remaining performance obligation, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 1
Revenue, remaining performance obligation, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 0.5
Revenue, remaining performance obligation, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2026-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 0.2
Revenue, remaining performance obligation, period	1 year
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2027-01-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, amount	$ 1.2
Revenue, remaining performance obligation, period

Weichai Transactions (Details)

Weichai Transactions (Details)	3 Months Ended
	Mar. 31, 2022USD ($)agreement	Mar. 31, 2021USD ($)	Mar. 25, 2022USD ($)	Dec. 31, 2021USD ($)	Dec. 10, 2021USD ($)
Subsidiary, Sale of Stock [Line Items]
Debt instrument, number of loan agreements | agreement	4
Purchased inventory	$ 4,300,000	$ 3,100,000
Outstanding payables	16,800,000			$ 12,500,000
Revolving credit facility | First Shareholder's Loan Agreement, Weichai
Subsidiary, Sale of Stock [Line Items]
Maximum borrowing capacity	130,000,000		$ 130,000,000
Revolving credit facility | Second Shareholder's Loan Agreement, Weichai
Subsidiary, Sale of Stock [Line Items]
Maximum borrowing capacity	25,000,000		$ 25,000,000
Revolving credit facility | Third Shareholder's Loan Agreement, Weichai
Subsidiary, Sale of Stock [Line Items]
Maximum borrowing capacity	50,000,000				$ 50,000,000
Revolving credit facility | Fourth Shareholder's Loan Agreement, Weichai
Subsidiary, Sale of Stock [Line Items]
Maximum borrowing capacity	$ 30,000,000

Property, Plant and Equipment_2

Property, Plant and Equipment (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, at cost	$ 52,376	$ 52,590
Accumulated depreciation	(36,391)	(35,246)
Property, plant and equipment, net	15,985	17,344
Leasehold improvements
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, at cost	7,107	7,107
Machinery and equipment
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, at cost	44,382	44,358
Construction in progress
Property, Plant and Equipment [Line Items]
Total property, plant and equipment, at cost	$ 887	$ 1,125

Goodwill and Other Intangible_2

Goodwill and Other Intangibles - Narrative (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill	$ 29,835	$ 29,835
Accumulated impairment losses	$ 11,600	$ 11,600

Goodwill and Other Intangible_3

Goodwill and Other Intangibles - Schedule of Finite-Lived Intangible Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	$ 37,340	$ 37,340
Accumulated Amortization	(30,097)	(29,556)
Net Book Value	7,243	7,784
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	34,940	34,940
Accumulated Amortization	(28,017)	(27,514)
Net Book Value	6,923	7,426
Developed technology
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	700	700
Accumulated Amortization	(695)	(680)
Net Book Value	5	20
Trade names and trademarks
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Value	1,700	1,700
Accumulated Amortization	(1,385)	(1,362)
Net Book Value	$ 315	$ 338

Debt - Schedule of Debt (Detail

Debt - Schedule of Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Short-term financing:
Short-term financing	$ 170,000	$ 155,000
Other short-term financing	40,000	25,000
Long-term debt:
Finance leases and other debt	809	890
Total long-term debt and finance leases	25,809	25,890
Less: Current maturities of long-term debt and finance leases	223	254
Long-term debt	25,586	25,636
Unsecured senior notes
Long-term debt:
Unsecured senior notes	25,000	25,000
Revolving credit facility
Short-term financing:
Short-term financing	130,000	130,000
Long-term debt:
Debt issuance costs	$ 1,700	$ 800

Debt - Narrative (Details)

Debt - Narrative (Details)	Apr. 20, 2022USD ($)	Mar. 25, 2022USD ($)dayagreement	Dec. 10, 2021USD ($)	Mar. 31, 2022USD ($)	Dec. 31, 2021USD ($)	Mar. 31, 2021USD ($)
Debt Instrument [Line Items]
Short-term financing				$ 170,000,000	$ 155,000,000
Debt instrument, number of loan agreements amended | agreement		2
Debt, long-term and short-term, combined amount				195,800,000
Cash and cash equivalents				2,267,000	6,255,000	$ 23,404,000
Revolving credit facility
Debt Instrument [Line Items]
Short-term financing				130,000,000	$ 130,000,000
First, Second, And Fourth Shareholder's Loan Agreement, Weichai | Subsequent Event
Debt Instrument [Line Items]
Debt instrument, incremental borrowing cost	1.00%
First, Second, And Fourth Shareholder's Loan Agreement, Weichai | Secured Overnight Financing Rate (SOFR) Overnight Index Swap Rate | Subsequent Event
Debt Instrument [Line Items]
Basis spread on variable rate	4.65%
First Shareholder's Loan Agreement, Weichai | Revolving credit facility
Debt Instrument [Line Items]
Short-term financing				0
Second Shareholder's Loan Agreement, Weichai | Revolving credit facility
Debt Instrument [Line Items]
Short-term financing				25,000,000
Third Shareholder's Loan Agreement, Weichai | Revolving credit facility
Debt Instrument [Line Items]
Short-term financing				40,000,000
Revolving credit facility | Second Standard Chartered Bank Credit Agreement
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 130,000,000		130,000,000
Number of days to submit borrowing request | day		5
Short-term financing				130,000,000
Basis spread on variable rate		2.95%
Revolving credit facility | First Shareholder's Loan Agreement, Weichai
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 130,000,000		130,000,000
Revolving credit facility | Second Shareholder's Loan Agreement, Weichai
Debt Instrument [Line Items]
Maximum borrowing capacity		$ 25,000,000		25,000,000
Revolving credit facility | Fourth Shareholder's Loan Agreement, Weichai
Debt Instrument [Line Items]
Maximum borrowing capacity				30,000,000
Revolving credit facility | Fourth Shareholder's Loan Agreement, Weichai | Subsequent Event
Debt Instrument [Line Items]
Maximum borrowing capacity	$ 30,000,000
Revolving credit facility | Third Shareholder's Loan Agreement, Weichai
Debt Instrument [Line Items]
Maximum borrowing capacity			$ 50,000,000	$ 50,000,000
Revolving credit facility | Third Shareholder's Loan Agreement, Weichai | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate			4.50%

Leases - Narrative (Details)

Leases - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lease expense	$ 1,384	$ 1,744
Weighted-average remaining lease term, operating leases	5 years 9 months 18 days		5 years 9 months 18 days
Weighted-average remaining lease term, financing leases	3 years 4 months 24 days		3 years 4 months 24 days
Weighted-average discount rate for operating leases	7.00%		7.00%
Weighted-average discount rate for financing leases	6.60%		6.50%
Cost of Sales
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lease expense	$ 1,600	1,500
Research and Development Expense
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lease expense	$ 100	100
Selling, General and Administrative Expenses
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lease expense		100
Interest Expense
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Lease expense		$ 100

Leases - Components of Lease Ex

Leases - Components of Lease Expense (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Leases [Abstract]
Operating lease cost	$ 1,179	$ 1,242
Finance lease cost
Amortization of right-of-use (“ROU”) asset	48	52
Interest expense	6	10
Short-term lease cost	36	102
Variable lease cost	380	338
Sublease income	(265)	0
Total lease cost	$ 1,384	$ 1,744

Leases - Supplemental Cash Flow

Leases - Supplemental Cash Flow Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Cash paid for amounts included in the measurement of lease liabilities
Operating cash flows paid for operating leases	$ 1,221	$ 1,257
Operating cash flows paid for interest portion of finance leases	6	10
Financing cash flows paid for principal portion of finance leases	$ 51	$ 51

Leases - Supplemental Balance S

Leases - Supplemental Balance Sheet Information (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Operating Leases
Operating lease ROU assets, net	$ 12,613	$ 13,545
Operating lease liabilities, current	4,049	3,978
Operating lease liabilities, non-current	9,258	10,304
Total operating lease liabilities	13,307	14,282
Finance Leases
Finance lease ROU assets, net	316	364
Finance lease liabilities, current	119	147
Finance lease liabilities, non-current	238	260
Total finance lease liabilities	$ 357	$ 407
Operating ROU assets, net, statement of financial position, extensible list	Other noncurrent assets	Other noncurrent assets
Finance ROU assets, net, statement of financial position, extensible list	Property, plant and equipment, net	Property, plant and equipment, net
Operating lease liabilities, current, statement of financial position, extensible list	Other accrued liabilities	Other accrued liabilities
Finance lease liabilities, current, statement of financial position, extensible list	Current maturities of long-term debt	Current maturities of long-term debt
Operating lease liabilities, noncurrent, statement of financial position, extensible list	Other noncurrent liabilities	Other noncurrent liabilities
Finance lease liabilities, noncurrent, statement of financial position, extensible list	Long-term debt, net of current maturities	Long-term debt, net of current maturities

Leases - Maturity Analysis of L

Leases - Maturity Analysis of Lease Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Operating Leases
Nine months ending December 31, 2022	$ 3,637
Year ending December 31, 2023	3,347
Year ending December 31, 2024	1,815
Year ending December 31, 2025	1,851
Year ending December 31, 2026	1,515
Thereafter	4,023
Total undiscounted lease payments	16,188
Less: imputed interest	2,881
Total lease liabilities	13,307	$ 14,282
Finance Leases
Nine months ending December 31, 2022	111
Year ending December 31, 2023	103
Year ending December 31, 2024	84
Year ending December 31, 2025	82
Year ending December 31, 2026	17
Thereafter	0
Total undiscounted lease payments	397
Less: imputed interest	40
Total lease liabilities	$ 357	$ 407

Fair Value of Financial Instr_3

Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	$ 170,000	$ 155,000
Revolving credit facility
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	130,000	130,000
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other financing	65,000	50,000
Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other financing	0	0
Fair Value, Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other financing	65,000	50,000
Fair Value, Measurements, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Other financing	0	0
Fair Value, Measurements, Recurring | Revolving credit facility
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Carrying Value	130,000	130,000
Fair Value, Measurements, Recurring | Revolving credit facility | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Revolving credit facility	0	0
Fair Value, Measurements, Recurring | Revolving credit facility | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Revolving credit facility	130,000	130,000
Fair Value, Measurements, Recurring | Revolving credit facility | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Revolving credit facility	$ 0	$ 0

Commitments and Contingencies (

Commitments and Contingencies (Details)	Mar. 31, 2020USD ($)	Sep. 30, 2021USD ($)	Aug. 31, 2021USD ($)	Jul. 31, 2021USD ($)	Oct. 31, 2020	Feb. 29, 2020USD ($)	Oct. 31, 2018USD ($)	Mar. 31, 2022USD ($)letterOfCredit	Mar. 31, 2021USD ($)	Mar. 31, 2020USD ($)	Dec. 31, 2021USD ($)
Loss Contingencies [Line Items]
Accrued penalties								$ 1,165,000			$ 894,000
Insurance coverage										$ 30,000,000
Number of outstanding letters of credit | letterOfCredit								5
Outstanding letters of credit amount								$ 2,100,000			2,100,000
Restricted cash								3,160,000	$ 3,299,000		3,477,000
Cost of sales								82,229,000	93,101,000
Supply Commitment Fee, COVID-19
Loss Contingencies [Line Items]
Cost of sales								6,900,000
Indemnification Agreement
Loss Contingencies [Line Items]
Related costs								200,000	$ 3,200,000
Jerome Treadwell v. The Company
Loss Contingencies [Line Items]
Recovery per negligent violation							$ 1,000
Recovery per intentional or reckless violation							$ 5,000
Stay case term					60 days
Estimated liability								1,000,000			300,000
Mast Powertrain v. The Company
Loss Contingencies [Line Items]
Damages sought	$ 4,500,000					$ 9,000,000
Litigation settlement payment				$ 1,500,000
Accrued penalties								0			$ 500,000
Gary Winemaster v. The Company
Loss Contingencies [Line Items]
Damages sought			$ 7,200,000
Legal settlement			$ 7,500,000
Jeffrey Ehlers Litigation
Loss Contingencies [Line Items]
Estimated liability								0
Damages sought		$ 2,400,000
Rick Lulloff Litigation
Loss Contingencies [Line Items]
Estimated liability								$ 0
Damages sought		$ 1,200,000

Income Taxes (Details)

Income Taxes (Details)	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Income Tax Disclosure [Abstract]
Effective income tax rate	(17.40%)	(2.20%)

Stockholders' Equity (Details)

Stockholders' Equity (Details) shares in Thousands	Mar. 31, 2022shares
Common Shares Issued
Beginning balance (in shares)	23,117
Ending balance (in shares)	23,117
Treasury Stock Shares
Balance at beginning of period (in shares)	191
Balance at end of period (in shares)	190
Common Shares Outstanding
Balance at beginning of period (in shares)	22,926
Balance at end of period (in shares)	22,927

Loss Per Share (Details)

Loss Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Numerator:
Net loss	$ (2,599)	$ (18,150)
Shares used in computing net loss per share:
Weighted average basic shares outstanding - basic (in shares)	22,927	22,892
Effect of dilutive securities (in shares)	0	0
Weighted average common shares outstanding - diluted (in shares)	22,927	22,892
Loss per common share:
Loss per share of common stock – basic (in dollars per share)	$ (0.11)	$ (0.79)
Loss per share of common stock – diluted (in dollars per share)	$ (0.11)	$ (0.79)
Antidilutive shares (in shares)	200	200

Related Party Transactions (Det

Related Party Transactions (Details) - Corporate Joint Venture - USD ($) $ in Millions	1 Months Ended	3 Months Ended	12 Months Ended
	Dec. 31, 2012	Jun. 30, 2021	Dec. 31, 2015
Green Power
Related Party Transaction [Line Items]
Investment amount with related party	$ 0.9
Percent of noncontrolling interest	50.00%
Green Power | MAT-PSI Holdings, LLC
Related Party Transaction [Line Items]
Ownership interest	100.00%
Doosan-PSI, LLC
Related Party Transaction [Line Items]
Investment amount with related party			$ 1
Percent of noncontrolling interest			50.00%
Cash distribution from joint venture		$ 2.2