Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended		12 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Cash flows from operating activities:
Net income	$ 3,258	$ 3,412	$ 5,515	$ 1,864	$ 6,670	$ 7,379
Adjustment to reconcile net income to net cash provided by (used in) operating activities:
Depreciation and amortization	2,452		2,749		4,648	5,520
Unrealized foreign currency loss					(52)	258
Net gain on interest rate swaps						(248)
Loss on divestitures, net of selling costs						70
Debt discount amortization					208	847
Share-based compensation expense					751	1,756
Bad debt expense	400		300		457	394
Inventory reserve expense					269	361
Deferred income tax benefit						(337)
Changes in operating assets and liabilities, net of divestitures:
Accounts receivable					8,623	(7,046)
Costs and estimated earnings in excess of billings on uncompleted contracts					(3,446)	(2,416)
Inventories					1,694	(1,929)
Prepaid expense and other current assets					(1,068)	(3,366)
Deferred charges and other assets					(1,553)	(1,703)
Accounts payable and accrued expenses					(5,229)	(8,291)
Billings in excess of costs and estimated earnings on uncompleted contracts					(10,057)	1,854
Income taxes payable						(1,656)
Other liabilities					193	(2,744)
Net cash provided by (used in) operating activities					2,108	(11,297)
Cash flows from investing activities:
Acquisitions of property and equipment					(1,992)	(1,201)
Net cash paid for acquisition					(6,124)
Net cash used in by investing activities					(8,116)	(1,201)
Cash flows from financing activities:
Borrowings on revolving credit lines					72,500	36,300
Repayments on revolving credit lines					(59,000)	(35,447)
Repayments of long-term debt					(1,250)	(1,700)
Deferred financing fees paid						(1,117)
Payments on finance leases and financing liability					(203)	(232)
Proceeds from employee stock purchase plan and exercise of stock options						75
Net cash provided by (used in) financing activities					12,047	(2,121)
Effect of exchange rate changes on cash, cash equivalents and restricted cash					141	136
Net increase (decrease) in cash, cash equivalents and restricted cash					6,180	(14,483)
Cash, cash equivalents and restricted cash at beginning of period		$ 36,958		$ 44,438	36,958	44,438	$ 44,438
Cash, cash equivalents and restricted cash at end of period	$ 43,138		$ 29,955		43,138	29,955	$ 36,958
Cash paid (received) during the period for:
Interest					1,850	2,300
Income taxes					$ (658)	$ 3,582