Consolidated Statements of Cash Flows - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Cash flows from operating activities:
Net income	$ 5,807,000	$ (1,775,000)
Adjustments to reconcile net income (loss) to cash provided by (used in) operating activities:
Depreciation and amortization	6,171,000	6,286,000
Noncash operating lease expense	4,033,000	3,799,000
Impairment of goodwill	0	4,359,000
Provision for doubtful accounts	100,000	95,000
Stock-based compensation expense	1,068,000	1,766,000
Loss on debt extinguishment	0	513,000
Amortization of debt discount and issuance costs	2,157,000	1,392,000
Deferred tax benefit	(1,301,000)	(609,000)
Change in fair value of warrant liability	1,634,000	(588,000)
Gain on embedded derivative	0	(388,000)
Gain on sale of property and equipment	(95,000)	(57,000)
Changes in operating assets and liabilities:
Accounts receivable	19,200,000	659,000
Contract assets	10,090,000	(13,378,000)
Other current assets	(115,000)	30,139,000
Accounts payable, including retainage	(19,504,000)	11,914,000
Contract liabilities	4,278,000	(6,446,000)
Prepaid income taxes	494,000	58,000
Accrued taxes payable	1,659,000	12,000
Accrued expenses and other current liabilities	4,713,000	(34,686,000)
Operating lease liabilities	(4,337,000)	(3,654,000)
Other long-term liabilities	3,763,000	(337,000)
Net cash provided by (used in) operating activities	39,815,000	(926,000)
Cash flows from investing activities:
Proceeds from sale of property and equipment	162,000	168,000
Advances to joint ventures	(2,000)	4,000
Purchase of property and equipment	(1,483,000)	(2,663,000)
Net cash used in investing activities	(1,323,000)	(2,491,000)
Cash flows from financing activities:
Bank overdrafts	0	(1,333,000)
Payments on Credit Agreement term loan	0	(14,335,000)
Proceeds from Credit Agreement revolver	0	17,500,000
Payments on Credit Agreement revolver	0	(17,500,000)
Proceeds from 2019 Revolving Credit Facility	7,250,000	32,500,000
Payments on 2019 Revolving Credit Facility	(7,250,000)	(32,500,000)
Proceeds from 2019 Refinancing Term Loan, net of debt discount	0	38,644,000
Payments on 2019 Refinancing Term Loan	(2,000,000)	0
Warrants issued in conjunction with the 2019 Refinancing Term Loan	0	969,000
Embedded derivative associated with the 2019 Refinancing Term Loan	0	388,000
Payments on Bridge Term Loan	0	(7,736,000)
Payments on finance leases	(2,664,000)	(2,547,000)
Proceeds from contributions to employee stock purchase plan	191,000	0
Taxes paid related to net-share settlement of equity awards	(216,000)	(131,000)
Payments of debt issuance costs	0	(3,777,000)
Net cash provided by (used in) financing activities	(4,689,000)	10,142,000
Increase in cash, cash equivalents and restricted cash	33,803,000	6,725,000
Cash, cash equivalents and restricted cash, beginning of year	8,457,000	1,732,000
Cash, cash equivalents and restricted cash, end of year	42,260,000	8,457,000
Noncash investing and financing transactions:
Debt issuance costs related to 2019 Refinancing Agreement paid-in-kind	0	1,000,000
Right of use assets obtained in exchange for new operating lease liabilities	1,096,000	3,355,000
Right of use assets obtained in exchange for new finance lease liabilities	2,624,000	3,578,000
Right of use assets disposed or adjusted modifying operating leases liabilities	621,000	1,651,000
Right of use assets disposed or adjusted modifying finance leases liabilities	(86,000)	(78,000)
Interest paid	$ 6,467,000	$ 4,607,000