CONSOLIDATED STATEMENTS OF INCOME AND COMPREHENSIVE INCOME - USD ($) shares in Thousands, $ in Thousands		12 Months Ended
		Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
CONSOLIDATED STATEMENTS OF INCOME AND COMPREHENSIVE INCOME
Revenues		$ 245,893	$ 232,434	$ 249,682
Cost of goods sold		172,889	163,662	176,256
Gross margin		73,004	68,772	73,426
Operating costs and expenses:
Selling		9,986	8,149	8,709
General and administrative		24,333	22,251	23,972
Engineering and development		16,170	14,229	13,881
Business development		428	569
Amortization of intangible assets		3,204	2,644	2,714
Total operating costs and expenses		54,121	47,842	49,276
Operating income		18,883	20,930	24,150
Other expense (income):
Interest expense		6,449	6,023	6,435
Other expense (income), net		(369)	(514)	(908)
Total other expense (income) , net		6,080	5,509	5,527
Income before income taxes		12,803	15,421	18,623
Provision for income taxes		(3,725)	(4,347)	(4,763)
Net income		$ 9,078	$ 11,074	$ 13,860
Basic earnings per share:
Earnings per share (in dollars per share)		$ 1.01	$ 1.20	$ 1.52
Basic weighted average common shares (in shares)		9,011	9,228	9,145
Diluted earnings per share:
Earnings per share (in dollars per share)		$ 1.00	$ 1.20	$ 1.51
Diluted weighted average common shares (in shares)		9,105	9,238	9,165
Net income		$ 9,078	$ 11,074	$ 13,860
Other comprehensive income:
Foreign currency translation adjustment		(1,989)	(4,334)	(5,601)
Change in accumulated loss on derivatives		(3)	(25)	(43)
Pension adjustments	[1]	(134)	165	(663)
Comprehensive income		$ 6,952	$ 6,880	$ 7,553

[1] Net of tax of ($78), $114 and ($460) for the periods ending December 31, 2016, 2015 and 2014, respectively.