CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Cash Flows From Operating Activities:
Net income	$ 15,925	$ 8,036	$ 9,078
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization	11,576	10,274	9,749
Deferred income taxes	(76)	3,713	1,770
Loss on sale of assets	19
Provision for doubtful accounts	192	39	167
Provision for excess and obsolete inventory	682	480	351
Provision for warranty	(13)	234	(138)
Write-off of debt issue costs recorded in interest expense (Note 7)			1,052
Debt issue cost amortization recorded in interest expense	148	165	380
Restricted stock compensation	2,643	2,026	1,893
Other	57	(756)	(652)
Changes in operating assets and liabilities, net of acquisition:
(Increase) decrease in trade receivables	(4,110)	(4,051)	(3,719)
(Increase) decrease in inventories	(17,327)	18	(928)
(Increase) decrease in prepaid expenses and other assets	(835)	(328)	69
Increase (decrease) in accounts payable	6,533	1,277	(956)
Increase (decrease) in accrued liabilities and other liabilities	2,038	4,280	(3,813)
Net cash provided by operating activities	17,452	25,407	14,303
Cash Flows From Investing Activities:
Consideration paid for acquisitions, net of cash acquired	(77,413)		(16,205)
Purchase of property and equipment	(14,333)	(6,201)	(5,188)
Net cash used in investing activities	(91,746)	(6,201)	(21,393)
Cash Flows From Financing Activities:
Borrowings (repayments) on lines-of-credit	(454)	(518)	(5,709)
Principal payments of long-term debt	(13,278)	(18,389)	(67,125)
Proceeds from issuance of long-term debt	83,163		76,321
Payment of debt issuance costs	(72)		(745)
Sale of restricted stock	1,076
Dividends paid to stockholders	(1,079)	(959)	(942)
Tax withholdings related to net share settlements of restricted stock	(1,579)	(1,513)	(1,054)
Stock transactions under employee benefit stock plans		1,213	834
Net cash provided by (used in) financing activities	67,777	(20,166)	1,580
Effect of foreign exchange rate changes on cash	(400)	1,067	(285)
Net (decrease) increase in cash and cash equivalents	(6,917)	107	(5,795)
Cash and cash equivalents at beginning of period	15,590	15,483	21,278
Cash and cash equivalents at end of period	8,673	15,590	15,483
Net cash paid during the period for:
Interest	2,272	2,261	5,048
Income taxes	$ 7,014	$ 2,087	$ 1,148