CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $) In Thousands, unless otherwise specified	Total	Common Stock	Treasury Stock	Additional Capital	Accumulated Other Comprehensive Loss	Accumulated Deficit
Balance at Dec. 31, 2009	$ 347,166	$ 24	$ (853)	$ 494,783	$ (1,423)	$ (145,365)
Balance (in shares) at Dec. 31, 2009			(56)
Balance (in shares) at Dec. 31, 2009		24,045
Increase (Decrease) in Stockholders' Equity
Common stock issued in equity offering, net of costs	107,917	4		107,913
Common stock issued in equity offering, net of costs (in shares)		3,651
Common stock issued on exercise of stock options and warrants	7,818	1		7,817
Common stock issued on exercise of stock options and warrants (in shares)		753
Common stock issued in purchase (in shares)		41
Common stock issued under employee stock purchase plan	128			128
Common stock issued under employee stock purchase plan (in shares)		5
Common stock issued on vesting of restricted stock and restricted stock units (in shares)		10
Common stock issued pursuant to restricted stock/restricted stock unit agreement, net of shares tendered to satisfy required tax withholding	(1,620)			(1,620)
Common stock issued pursuant to restricted stock/restricted stock unit agreement, net of shares tendered to satisfy required tax withholding (in shares)		74
Tax benefit from exercise of non-qualified stock options and vesting of restricted stock	879			879
Purchase of treasury stock	(13,148)		(13,148)
Purchase of treasury stock (in shares)			(601)
Share-based compensation	4,805			4,805
Other comprehensive income (loss)	1,398				1,398
Net income (loss)	41,569					41,569
Balance at Dec. 31, 2010	496,912	29	(14,001)	614,705	(25)	(103,796)
Balance (in shares) at Dec. 31, 2010			(657)
Balance (in shares) at Dec. 31, 2010		28,579
Increase (Decrease) in Stockholders' Equity
Common stock issued on exercise of stock options and warrants	212			212
Common stock issued on exercise of stock options and warrants (in shares)		16
Common stock issued under employee stock purchase plan	180			180
Common stock issued under employee stock purchase plan (in shares)		6
Common stock issued on vesting of restricted stock and restricted stock units (in shares)		32
Common stock issued pursuant to restricted stock/restricted stock unit agreement, net of shares tendered to satisfy required tax withholding	(1,129)			(1,129)
Common stock issued pursuant to restricted stock/restricted stock unit agreement, net of shares tendered to satisfy required tax withholding (in shares)		74
Purchase of treasury stock	(21,547)		(21,547)
Purchase of treasury stock (in shares)			(847)
Share-based compensation	12,430			12,430
Other comprehensive income (loss)	(3,756)				(3,756)
Net income (loss)	24,484					24,484
Balance at Dec. 31, 2011	507,786	29	(35,548)	626,398	(3,781)	(79,312)
Balance (in shares) at Dec. 31, 2011			(1,504)
Balance (in shares) at Dec. 31, 2011	28,707	28,707
Increase (Decrease) in Stockholders' Equity
Common stock issued on exercise of stock options and warrants	269			269
Common stock issued on exercise of stock options and warrants (in shares)		38
Common stock issued in purchase	3,314			3,314
Common stock issued in purchase (in shares)		357
Common stock issued under employee stock purchase plan	157			157
Common stock issued under employee stock purchase plan (in shares)		14
Common stock issued on vesting of restricted stock and restricted stock units (in shares)		22
Common stock issued pursuant to restricted stock/restricted stock unit agreement, net of shares tendered to satisfy required tax withholding	(93)			(93)
Common stock issued pursuant to restricted stock/restricted stock unit agreement, net of shares tendered to satisfy required tax withholding (in shares)		25
Share-based compensation	17,470			17,470
Other comprehensive income (loss)	2,126				2,126
Net income (loss)	(239,835)					(239,835)
Balance at Dec. 31, 2012	$ 291,194	$ 29	$ (35,548)	$ 647,515	$ (1,655)	$ (319,147)
Balance (in shares) at Dec. 31, 2012			(1,504)
Balance (in shares) at Dec. 31, 2012	29,163	29,163