Consolidated Statements of Changes in Stockholders' Equity - USD ($) $ in Thousands	Common Stock	Additional Paid-in Capital	Retained Earnings	Common Stock Held in Treasury	Accumulated Other Comprehensive Income.	Total
Balance at Dec. 31, 2013	$ 522	$ 240,057	$ 436,570	$ (268,253)	$ 8,536	$ 417,432
Increase (Decrease) in Stockholders' Equity
Net loss			50,892			50,892
Other comprehensive loss					(14,430)	(14,430)
Issuance of common stock in connection with employee stock option plan (14,228 shares, 39,002 shares, and 0 shares) and for issuance of common stock in connection with director stock option exercises (0 net settled shares, 0 net settled shares, and 24,498 net settled shares) and for restricted stock unit awards (1,123,720 shares, 1,159,047 shares, and 1,073,884 shares), including net excess tax benefit of $0.6 million, $2.1 million, and $0.2 million, for the year end 2014, 2015, and 2016, respectively		(16,244)		16,020		(224)
Issuance of common stock for the employee stock purchase plan (71,587 shares, 70,924 shares, and 95,981 shares) for the year end 2014, 2015, and 2016, respectively		963				963
Purchase of common stock for treasury (2,671,637 shares, 1,992,831 shares, and 1,336,132 shares) for the year end 2014, 2015, and 2016, respectively				(48,165)		(48,165)
Shares withheld for net settlements of share-based awards (367,367 shares, 418,135 shares, and 391,195 shares) for year end 2014, 2015, and 2016				(6,231)		(6,231)
Share-based compensation		15,359				15,359
Balance at Dec. 31, 2014	522	240,135	487,462	(306,629)	(5,894)	415,596
Increase (Decrease) in Stockholders' Equity
Net loss			91,570			91,570
Other comprehensive loss					(13,601)	(13,601)
Issuance of common stock in connection with employee stock option plan (14,228 shares, 39,002 shares, and 0 shares) and for issuance of common stock in connection with director stock option exercises (0 net settled shares, 0 net settled shares, and 24,498 net settled shares) and for restricted stock unit awards (1,123,720 shares, 1,159,047 shares, and 1,073,884 shares), including net excess tax benefit of $0.6 million, $2.1 million, and $0.2 million, for the year end 2014, 2015, and 2016, respectively		(20,299)		20,621		322
Issuance of common stock for the employee stock purchase plan (71,587 shares, 70,924 shares, and 95,981 shares) for the year end 2014, 2015, and 2016, respectively	1	1,166				1,167
Purchase of common stock for treasury (2,671,637 shares, 1,992,831 shares, and 1,336,132 shares) for the year end 2014, 2015, and 2016, respectively				(42,046)		(42,046)
Dividend declared on common stock		2	(7,406)	109		(7,295)
Shares withheld for net settlements of share-based awards (367,367 shares, 418,135 shares, and 391,195 shares) for year end 2014, 2015, and 2016				(8,978)		(8,978)
Share-based compensation		18,086				18,086
Balance at Dec. 31, 2015	523	239,090	571,626	(336,923)	(19,495)	454,821
Increase (Decrease) in Stockholders' Equity
Net loss			(25,918)			(25,918)
Other comprehensive loss					(14,482)	(14,482)
Issuance of common stock in connection with employee stock option plan (14,228 shares, 39,002 shares, and 0 shares) and for issuance of common stock in connection with director stock option exercises (0 net settled shares, 0 net settled shares, and 24,498 net settled shares) and for restricted stock unit awards (1,123,720 shares, 1,159,047 shares, and 1,073,884 shares), including net excess tax benefit of $0.6 million, $2.1 million, and $0.2 million, for the year end 2014, 2015, and 2016, respectively	1	(16,600)		19,237		2,638
Issuance of common stock for the employee stock purchase plan (71,587 shares, 70,924 shares, and 95,981 shares) for the year end 2014, 2015, and 2016, respectively	1	1,320				1,321
Purchase of common stock for treasury (2,671,637 shares, 1,992,831 shares, and 1,336,132 shares) for the year end 2014, 2015, and 2016, respectively				(22,112)		(22,112)
Dividend declared on common stock		4	(9,358)	111		(9,243)
Shares withheld for net settlements of share-based awards (367,367 shares, 418,135 shares, and 391,195 shares) for year end 2014, 2015, and 2016				(6,795)		(6,795)
Share-based compensation		24,934				24,934
Balance at Dec. 31, 2016	$ 525	$ 248,748	$ 536,350	$ (346,482)	$ (33,977)	$ 405,164