Consolidated Statements of Changes in Stockholders' Equity (USD $) In Thousands, unless otherwise specified	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Common Stock Held in Treasury	Accumulated Other Comprehensive Income/(Loss)
Balance at Dec. 31, 2010	$ 870,068	$ 518	$ 246,085	$ 833,133	$ (220,161)	$ 10,493
Increase (Decrease) in Stockholders' Equity
Net income (loss)	(179,789)			(179,789)
Other comprehensive income (loss)	(2,152)					(2,152)
Issuance of common stock for stock options (111,792 shares), restricted share awards (1,029,623 shares), (670,933 shares) and (787,399 shares) and employee stock unit awards (71,580 shares) and (288,917 shares), including tax benefit shortfall and award cancellations of $1.5 million, $4.1 million and $3.3 million for the years 2013, 2012 and 2011, respectively	5,229		(19,285)		24,514
Issuance of common stock for the employee stock purchase plan (121,363 shares), (137,782 shares) and (108,621 shares) for the years 2013, 2012 and 2011, respectively	1,254	1	1,253
Purchase of common stock for treasury (2,005,200 shares), (2,470,000 shares) and (2,974,200 shares) for the years 2013, 2012 and 2011, respectively	(38,928)				(38,928)
Shares withheld for net settlements of share-based awards (352,051 shares), (270,467 shares) and (369,099 shares) for the years 2013, 2012 and 2011, respectively	(5,984)				(5,984)
Share-based compensation	21,416		21,416
Balance at Dec. 31, 2011	671,114	519	249,469	653,344	(240,559)	8,341
Increase (Decrease) in Stockholders' Equity
Net income (loss)	(247,859)			(247,859)
Other comprehensive income (loss)	3,533					3,533
Issuance of common stock for stock options (111,792 shares), restricted share awards (1,029,623 shares), (670,933 shares) and (787,399 shares) and employee stock unit awards (71,580 shares) and (288,917 shares), including tax benefit shortfall and award cancellations of $1.5 million, $4.1 million and $3.3 million for the years 2013, 2012 and 2011, respectively	(2,584)		(16,306)		13,722
Awards reclassified to liability for cash settlement (259,840 shares)	(2,838)		(2,838)
Issuance of common stock for the employee stock purchase plan (121,363 shares), (137,782 shares) and (108,621 shares) for the years 2013, 2012 and 2011, respectively	1,131	1	1,130
Purchase of common stock for treasury (2,005,200 shares), (2,470,000 shares) and (2,974,200 shares) for the years 2013, 2012 and 2011, respectively	(23,457)				(23,457)
Shares withheld for net settlements of share-based awards (352,051 shares), (270,467 shares) and (369,099 shares) for the years 2013, 2012 and 2011, respectively	(2,817)				(2,817)
Share-based compensation	13,547		13,547
Balance at Dec. 31, 2012	409,770	520	245,002	405,485	(253,111)	11,874
Increase (Decrease) in Stockholders' Equity
Net income (loss)	31,085			31,085
Other comprehensive income (loss)	(3,338)					(3,338)
Issuance of common stock for stock options (111,792 shares), restricted share awards (1,029,623 shares), (670,933 shares) and (787,399 shares) and employee stock unit awards (71,580 shares) and (288,917 shares), including tax benefit shortfall and award cancellations of $1.5 million, $4.1 million and $3.3 million for the years 2013, 2012 and 2011, respectively	(2,215)		(19,774)		17,559
Issuance of common stock for the employee stock purchase plan (121,363 shares), (137,782 shares) and (108,621 shares) for the years 2013, 2012 and 2011, respectively	935	2	933
Purchase of common stock for treasury (2,005,200 shares), (2,470,000 shares) and (2,974,200 shares) for the years 2013, 2012 and 2011, respectively	(28,169)				(28,169)
Shares withheld for net settlements of share-based awards (352,051 shares), (270,467 shares) and (369,099 shares) for the years 2013, 2012 and 2011, respectively	(4,532)				(4,532)
Share-based compensation	13,896		13,896
Balance at Dec. 31, 2013	$ 417,432	$ 522	$ 240,057	$ 436,570	$ (268,253)	$ 8,536