Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Cash flows from operating activities:
Net income (loss)	$ 8,172	$ 17,707	$ (7,121)
Adjustments to reconcile net income (loss) to net cash provided by operating activities:
Depreciation and amortization	9,921	10,609	13,272
Unrealized foreign currency loss (gain)	346	(526)	836
Net gain on interest rate swaps		(248)	(276)
Impairment of property and equipment			300
Impairment of intangible assets	850
Fair value adjustments to earnout liabilities	1,193		(330)
Earnout payments			(2,862)
Loss (gain) on sale of property and equipment	63	78	(217)
Loss on divestitures, net of selling costs		70	4,390
Amortization of debt discount	415	1,060	1,143
Share based compensation expense	1,758	2,668	3,187
Bad debt expense	928	295	1,357
Inventory reserve expense	494	316	519
Deferred income tax expense (benefit)	1,038	(940)	(42)
Changes in operating assets and liabilities, net of acquisitions and divestitures:
Accounts receivable	8,367	(15,616)	(6,084)
Cost and estimated earnings of billings on uncompleted contracts	(9,561)	(5,029)	(4,557)
Inventories	4,366	(207)	(1,704)
Prepaid expenses and other current assets	(962)	(7,097)	773
Deferred charges and other assets	(4,095)	758	(416)
Accounts payable and accrued expenses	336	(4,028)	21,321
Billings in excess of costs and estimated earnings on uncompleted contracts	(17,635)	14,274	70
Income taxes payable	460	(1,671)	1,839
Other liabilities	(2,033)	(2,246)	(3,446)
Net cash provided by operating activities	4,421	10,227	21,952
Cash flows from investing activities:
Acquisitions of property and equipment	(3,945)	(5,655)	(3,090)
Net cash proceeds from divestitures			35,052
Net proceeds from sale of assets	605	509	6,296
Cash paid for acquisitions	(5,895)
Net cash (used in) provided by investing activities	(9,235)	(5,146)	38,258
Cash flows from financing activities:
Borrowings on revolving credit lines	96,000	45,300	10,500
Repayments on revolving credit lines.	(86,800)	(52,947)	(14,223)
Repayments of long-term debt	(5,009)	(2,950)	(41,356)
Deferred financing fees paid		(1,117)
Proceeds from sale-leaseback transactions			800
Payments on capital leases and sale-leaseback financing liability	(467)	(478)	(675)
Proceeds from employee stock purchase plan, exercise of stock options, and dividend reinvestment plan		76	54
Net cash provided by (used in) financing activities	3,724	(12,116)	(44,900)
Effect of exchange rate changes on cash and cash equivalents	1,943	(445)	(1,531)
Net increase (decrease) in cash, cash equivalents and restricted cash	853	(7,480)	13,779
Cash, cash equivalents and restricted cash at beginning of year	36,958	44,438	30,659
Cash, cash equivalents and restricted cash at end of year	37,811	36,958	44,438
Cash paid during the period for:
Interest	3,172	3,549	5,559
Income taxes	$ 2,156	$ 5,908	$ 10,205