Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock (0.01 Par) [Member]	Additional Paid-in Capital [Member]	Retained Earnings (Accumulated Deficit) [Member]	Treasury Stock at Cost [Member]	Accumulated Other Comprehensive Loss [Member]
Balance at Dec. 31, 2013	$ 193,027	$ 192	$ 167,908	$ 27,711	$ (1,170)	$ (1,614)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	27,098	0	0	27,098	0	0
Foreign currency translation adjustments	(5,783)	0	0	0	0	(5,783)
Repurchases of common stock in the open market	(66,640)	(21)	(62,927)	0	(3,692)	0
Stock-based compensation expense	2,128	0	2,128	0	0	0
Income tax benefit from stock-based compensation	2,506	0	2,506	0	0	0
Shares withheld in exchange for tax withholding payments on stock-based compensation	(3,407)	0	(3,407)	0	0	0
Issuance of stock for employer contributions to retirement plan	2,469	0	616	0	1,853	0
Net issuances of stock pursuant to stock compensation plans and other	327		(2,301)	0	2,628	0
Balance at Dec. 31, 2014	151,725	171	104,523	54,809	(381)	(7,397)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	18,789	0	0	18,789	0	0
Foreign currency translation adjustments	(5,404)	0	0	0	0	(5,404)
Repurchases of common stock in the open market	(12,347)	0	0	0	(12,347)	0
Stock-based compensation expense	3,050	0	3,050	0	0	0
Income tax benefit from stock-based compensation	835	0	835	0	0	0
Shares withheld in exchange for tax withholding payments on stock-based compensation	(1,451)	0	(1,451)	0	0	0
Issuance of stock for employer contributions to retirement plan	2,711	1	681	0	2,029	0
Net issuances of stock pursuant to stock compensation plans and other	436	0	(1,766)	0	2,202	0
Balance at Dec. 31, 2015	158,344	172	105,872	73,598	(8,497)	(12,801)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	20,247	0	0	20,247	0	0
Foreign currency translation adjustments	(8,661)	0	0	0	0	(8,661)
Repurchases of common stock in the open market	(7,959)	0	0	0	(7,959)	0
Stock-based compensation expense	3,229	0	3,229	0	0	0
Income tax benefit from stock-based compensation	137	0	137	0	0	0
Shares withheld in exchange for tax withholding payments on stock-based compensation	(771)	0	(771)	0	0	0
Issuance of stock for employer contributions to retirement plan	2,708	0	(34)	0	2,742	0
Net issuances of stock pursuant to stock compensation plans and other	222	0	(1,864)	0	2,086	0
Balance at Dec. 31, 2016	$ 167,496	$ 172	$ 106,569	$ 93,845	$ (11,628)	$ (21,462)