CONSOLIDATED STATEMENTS OF STOCKHOLDERS' EQUITY (USD $) In Thousands	Common Stock	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Income (Loss)	Treasury Stock	Total
Balance, beginning at Dec. 31, 2009	$ 42	$ 439,943	$ (329,330)	$ (307)	$ (2,741)	$ 107,607
Balance, beginning (in shares) at Dec. 31, 2009	32,142				(200)
Net (loss) income			(69,725)			(69,725)
Other comprehensive income				15		15
Compensation expenses for share-based payment arrangements		9,515				9,515
Issuance of restricted stock, net of forfeitures (in shares)	173
Sale of common stock under employee stock purchase plans and exercise of stock options	1	3,895				3,896
Sale of common stock under stock incentive plan and exercise of stock options (in shares)	1,011
Balance, ending at Dec. 31, 2010	43	453,353	(399,055)	(292)	(2,741)	51,308
Balance, ending (in shares) at Dec. 31, 2010	33,326				(200)
Net (loss) income			10,381			10,381
Other comprehensive income				24		24
Compensation expenses for share-based payment arrangements		6,362				6,362
Issuance of restricted stock, net of forfeitures (in shares)	(38)
Sale of common stock under employee stock purchase plans and exercise of stock options	1	3,725				3,726
Sale of common stock under stock incentive plan and exercise of stock options (in shares)	758
Balance, ending at Dec. 31, 2011	44	463,440	(388,674)	(268)	(2,741)	71,801
Balance, ending (in shares) at Dec. 31, 2011	34,046				(200)
Net (loss) income			(35,431)			(35,431)
Other comprehensive income				8		8
Compensation expenses for share-based payment arrangements		6,536				6,536
Issuance of restricted stock, net of forfeitures (in shares)	(6)
Sale of common stock under stock incentive plan and exercise of stock options		306				306
Sale of common stock under stock incentive plan and exercise of stock options (in shares)	75
Sale of common stock in public offering, net of underwriting discounts and commissions ($1,518) and offering expenses ($434) (in shares)	12,650
Sale of common stock in public offering, net of underwriting discounts and commissions ($1,518) and offering expenses ($434)	17	23,331				23,348
Balance, ending at Dec. 31, 2012	$ 61	$ 493,613	$ (424,105)	$ (260)	$ (2,741)	$ 66,568
Balance, ending (in shares) at Dec. 31, 2012	46,765				(200)