Consolidated Statements of Stockholders’ Equity (USD $) In Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Retained Earnings [Member]	Treasury Stock [Member]	Total
Balance at Dec. 31, 2009	$ 917	$ 460,544	$ 8,635	$ (86,660)	$ (15,414)	$ 368,022
Employee stock options, restricted stock and employee stock purchase plan	14	3,838			(220)	3,632
Stock-based compensation expense		3,876				3,876
Income tax effect, net, of employee stock related activity		245				245
Settlement of interest rate swap, net of tax			858			858
Foreign currency translation			(912)			(912)
Net income (loss)				41,626		41,626
Balance at Dec. 31, 2010	931	468,503	8,581	(45,034)	(15,634)	417,347
Employee stock options, restricted stock and employee stock purchase plan	14	3,574			(441)	3,147
Stock-based compensation expense		4,535				4,535
Income tax effect, net, of employee stock related activity		592				592
Foreign currency translation			(7,792)			(7,792)
Net income (loss)				80,017		80,017
Balance at Dec. 31, 2011	945	477,204	789	34,983	(16,075)	497,846
Employee stock options, restricted stock and employee stock purchase plan	12	1,088			(402)	698
Stock-based compensation expense		7,103				7,103
Income tax effect, net, of employee stock related activity		(433)				(433)
Treasury shares purchased at cost					(50,145)	(50,145)
Foreign currency translation			(1,523)			(1,523)
Net income (loss)				60,032		60,032
Balance at Dec. 31, 2012	$ 957	$ 484,962	$ (734)	$ 95,015	$ (66,622)	$ 513,578