Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 12,066	$ 16,975	$ 15,022
Adjustments to reconcile net income to net cash provided from operating activities:
Depreciation and amortization	8,272	7,906	5,653
Provision for bad debts - accounts receivable	1,323	867	1,002
Share-based compensation expense	1,484	2,264	1,664
Deferred income tax (benefit) provision	(1,595)	(665)	5,114
Gain on disposals of property, plant and equipment	(5)		(1,048)
Change in fair value of acquisition-related contingent liabilities	(74)	(1,116)	(89)
Changes in assets and liabilities, net of acquisition of businesses:
Accounts receivable - trade	(17,104)	(4,886)	(4,731)
Accounts receivable - other	660	105	1,237
Contract asset	10,703	(3,382)
Inventories	(4,984)	2,429	4,250
Prepaid expenses and other current assets	(3,479)	2,622	(4,151)
Other assets	(1,717)	(1,257)	(4,504)
Accounts payable and other current liabilities	10,904	(1,344)	3,362
Long-term pension liability	2,138	(128)	(2,577)
Other long-term liabilities	1,415	(526)	2,523
Net cash provided from operating activities	20,007	19,864	22,727
CASH FLOWS FROM INVESTING ACTIVITIES
Additions to property, plant and equipment	(9,672)	(4,869)	(4,248)
Proceeds from disposals of property, plant and equipment	5		2,858
Acquisition of businesses, net of acquired cash		(85,597)	(7,988)
Net cash used in investing activities	(9,667)	(90,466)	(9,378)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from long-term debt	165,314	206,025	74,387
Repayment of long-term debt	(163,645)	(127,439)	(77,573)
Payment of cash dividends	(6,046)	(5,836)	(5,269)
Payment of acquisition-related contingent liabilities	(961)	(2,861)	(1,800)
Proceeds received on exercise of stock options	283	727	1,872
Tax benefit from vesting of acquisition related restricted stock	30	445	650
Tax withholdings on exercise of stock rights		(17)	(1,186)
Common stock reacquired and retired	(1,685)	(2,906)
Net cash provided from (used in) financing activities	(6,710)	68,138	(8,919)
Effect of exchange rates on cash	46	(304)	51
Net increase (decrease) in cash and cash equivalents	3,676	(2,768)	4,481
Cash and cash equivalents balance, beginning of year	5,362	8,130	3,649
Cash and cash equivalents balance, end of year	9,038	5,362	8,130
Supplemental disclosure of cash flow information:
Income taxes paid	7,146	1,088	7,173
Interest paid	$ 3,979	$ 2,724	$ 727