Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities
Net (loss) income	$ (14,560)	$ 20,220	$ (5,359)
Adjustments to reconcile net (loss) income to net cash used in operating activities:
Depreciation and amortization	22,608	23,893	26,096
Amortization of ROU operating leases	5,102	5,874	5,177
Amortization of ROU finance leases	2,822	3,324	2,312
Write-off of debt issuance costs upon debt modification	790		399
Amortization of deferred debt issuance costs	430	763	453
Deferred income taxes	(9)	17	71
Stock-based compensation	2,401	1,998	2,753
Gain on disposal of assets, net	(11,418)	(6,185)	(1,804)
Gain on involuntary disposition of assets, net		(2,859)
Allowance for credit losses		(487)
Change in operating assets and liabilities:
Accounts receivable	4,703	23,587	(51,709)
Income tax receivable	14	543	(495)
Inventory	371	148	503
Prepaid expenses and other	143	(1,070)	131
Contract assets	3,742	9,118	(32,172)
Accounts payable	589	(22,015)	28,894
Accrued liabilities	(6,544)	11,092	1,334
Operating lease liabilities	(4,940)	(5,399)	(5,843)
Income tax payable	(38)	(884)	1,523
Contract liabilities	(6,137)	(15,646)	27,020
Net cash provided by (used in) operating activities	69	46,032	(716)
Cash flows from investing activities:
Proceeds from sale of property and equipment	27,164	5,944	2,015
Purchase of property and equipment	(16,975)	(14,694)	(17,199)
Contributions to CSV life insurance		(99)	(721)
Insurance claim proceeds related to property and equipment	440	5,720	2,574
Net cash provided by (used in) investing activities	10,629	(3,129)	(13,331)
Cash flows from financing activities:
Borrowings from Credit Facility	53,000	10,000	63,000
Payments made on borrowings from Credit Facility	(49,120)	(48,204)	(70,210)
Proceeds from sale-leaseback arrangement			18,210
Loan costs from Credit Facility		(389)	(1,680)
Payments of finance lease liabilities	(3,035)	(3,619)	(2,906)
Payments related to tax withholding for stock-based compensation	(949)	(188)
Exercise of stock options	110		35
Net cash used in by financing activities	6	(42,400)	6,449
Net change in cash, cash equivalents and restricted cash	10,704	503	(7,598)
Cash, cash equivalents and restricted cash at beginning of period	1,589	1,086	8,684
Cash, cash equivalents and restricted cash at end of period	12,293	1,589	1,086
Supplemental disclosures of cash flow information, cash paid during the period for:
Interest	2,423	3,187	6,311
Taxes, net of refunds	$ 568	$ 2,174	$ 578