CONSOLIDATED STATEMENTS OF INCOME AND COMPREHENSIVE INCOME - USD ($) shares in Thousands, $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
CONSOLIDATED STATEMENTS OF INCOME AND COMPREHENSIVE INCOME
Revenues		$ 252,012	$ 245,893	$ 232,434
Cost of goods sold		176,333	172,889	163,662
Gross profit		75,679	73,004	68,772
Operating costs and expenses:
Selling		10,979	9,986	8,149
General and administrative		24,926	24,333	22,251
Engineering and development		17,542	16,170	14,229
Business development		213	428	569
Amortization of intangible assets		3,219	3,204	2,644
Total operating costs and expenses		56,879	54,121	47,842
Operating income		18,800	18,883	20,930
Other expense (income):
Interest expense		2,474	6,449	6,023
Other expense (income), net		190	(369)	(514)
Total other expense (income) , net		2,664	6,080	5,509
Income before income taxes		16,136	12,803	15,421
Provision for income taxes		(8,100)	(3,725)	(4,347)
Net income		$ 8,036	$ 9,078	$ 11,074
Basic earnings per share:
Earnings per share (in dollars per share)		$ 0.88	$ 1.01	$ 1.20
Basic weighted average common shares (in shares)		9,153	9,011	9,228
Diluted earnings per share:
Earnings per share (in dollars per share)		$ 0.87	$ 1.00	$ 1.20
Diluted weighted average common shares (in shares)		9,275	9,105	9,238
Net income		$ 8,036	$ 9,078	$ 11,074
Other comprehensive income:
Foreign currency translation adjustment		6,314	(1,989)	(4,334)
Change in accumulated loss on derivatives		226	(3)	(25)
Pension adjustments	[1]	(123)	(134)	165
Comprehensive income		$ 14,453	$ 6,952	$ 6,880

[1] Net of tax of $21, ($78) and $114 for the periods ending December 31, 2017, 2016 and 2015, respectively.