Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Treasury Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Retained Earnings
Balance at Dec. 31, 2013	$ 243,000	$ 6	$ (62,312)	$ 202,042	$ 2,777	$ 100,487
Balance (in shares) at Dec. 31, 2013		61,396,000	10,113,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	43,736
Total other comprehensive loss	(8,178)
Comprehensive income (loss)	35,558
Issuance of common stock upon exercise of stock awards	$ 182	$ 0		182
Issuance of common stock upon exercise of stock awards (in shares)	162,000	456,000
Issuance of treasury shares as consideration for acquisition	$ 9,035		$ 12,316			(3,281)
Issuance of treasury shares as consideration for acquisition (in shares)			1,092,000
Excess tax benefit derived from stock award exercises	(147)			(147)
Stock-based compensation expense	5,352			5,352
Balance at Dec. 31, 2014	292,980	$ 6	$ (49,996)	207,429	(5,401)	140,942
Balance (in shares) at Dec. 31, 2014		61,852,000	9,021,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	(33,063)
Total other comprehensive loss	(8,592)
Comprehensive income (loss)	(41,655)
Issuance of common stock upon exercise of stock awards	$ 675	$ 0		675
Issuance of common stock upon exercise of stock awards (in shares)	405,000	793,000
Issuance of treasury shares as consideration for acquisition	$ 1,571		$ 2,686			(1,115)
Issuance of treasury shares as consideration for acquisition (in shares)			238,000
Acquisition of treasury shares (in shares)	763,787
Acquisition of treasury shares	$ (4,900)
Excess tax benefit derived from stock award exercises	(411)			(411)
Stock-based compensation expense	5,873			5,873
Balance at Dec. 31, 2015	254,136	$ 6	$ (52,207)	213,566	(13,993)	106,764
Balance (in shares) at Dec. 31, 2015		62,645,000	9,547,000
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	4,370
Total other comprehensive loss	(6,806)
Comprehensive income (loss)	(2,436)
Issuance of common stock upon exercise of stock awards	$ 1,770	$ 0		1,770
Issuance of common stock upon exercise of stock awards (in shares)	420,000	746,000
Issuance of treasury shares as consideration for acquisition			$ 2,749			(737)
Issuance of treasury shares as consideration for acquisition (in shares)			244,000
Excess tax benefit derived from stock award exercises	$ 3,572			3,572
Stock-based compensation expense	5,572			5,572
Balance at Dec. 31, 2016	$ 264,626	$ 6	$ (49,458)	$ 224,480	$ (20,799)	$ 110,397
Balance (in shares) at Dec. 31, 2016		63,391,000	9,303,000