Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Cash flows from operating activities
Net income	$ (5,737)	$ 16,554
Adjustments to reconcile net income to net cash used in operating activities:
Depreciation and amortization	16,881	18,175
Amortization of ROU operating leases	3,967	4,449
Amortization of ROU finance leases	2,259	2,487
Write-off of debt issuance costs upon debt extinguishment	790
Amortization of deferred debt issuance costs	430	529
Deferred income taxes	20	27
Stock-based compensation	2,154	1,887
Gain on disposal of assets, net	(9,763)	(7,734)
Allowance for credit losses		(487)
Change in operating assets and liabilities:
Accounts receivable	10,402	12,151
Income tax receivable	(64)
Inventory	279	(291)
Prepaid expenses and other	2,006	1,667
Contract assets	14,601	(1,807)
Accounts payable	(16,841)	(22,583)
Accrued liabilities	(5,530)	26,282
Operating lease liabilities	(3,803)	(4,079)
Income tax payable	(307)	(1,037)
Contract liabilities	(7,504)	(7,814)
Net cash provided by operating activities	4,240	38,376
Cash flows from investing activities:
Proceeds from sale of property and equipment	25,643	5,821
Purchase of property and equipment	(11,594)	(9,444)
Contributions to CSV life insurance	0	(99)
Insurance claim proceeds related to property and equipment	440	1,525
Net cash provided by (used in) investing activities	14,489	(2,197)
Cash flows from financing activities:
Borrowings from Credit Facility	33,000	10,000
Payments made on borrowings from Credit Facility	(49,086)	(41,225)
Loan costs from Credit Facility		(369)
Payments of finance lease liabilities	(2,500)	(2,751)
Payments related to tax withholding for stock-based compensation	(949)	(188)
Exercise of stock options	110
Net cash used in by financing activities	(19,425)	(34,533)
Net change in cash and cash equivalents	(696)	1,646
Cash and cash equivalents at beginning of period	1,589	1,086
Cash and cash equivalents at end of period	893	2,732
Supplemental disclosures of cash flow information, cash paid during the period for:
Interest	2,220	2,676
Taxes, net of refunds	$ 691	$ 2,500