Consolidated Statements of Stockholders' Equity (Unaudited) (USD $) In Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Gain (Loss)	Treasury Stock
Balance, value at Dec. 31, 2011	$ 297,568	$ 480	$ 1,087,033	$ (789,621)	$ 21	$ (345)
Balance, shares at Dec. 31, 2011		480,389
Stock-based compensation	3,313	0	3,313	0	0	0
Issuance of common stock under Equity Incentive Plans, shares		779
Issuance of common stock under Equity Incentive Plans, value	276	1	275	0	0	0
Other	(136)	0	(136)	0	0	0
Repurchase of common stock	(285)	0	0	0	0	(285)
Net loss	(55,799)	0	0	(55,799)	0	0
Unrealized gain (loss) on investments	(41)	0	0	0	(41)	0
Balance, value at Jun. 30, 2012	244,896	481	1,090,485	(845,420)	(20)	(630)
Balance, shares at Jun. 30, 2012		481,168
Balance, value at Dec. 31, 2012	266,678	512	1,166,605	(899,832)	23	(630)
Balance, shares at Dec. 31, 2012		512,375
Stock-based compensation	3,978	0	3,978	0	0	0
Issuance of common stock under Equity Incentive Plans, shares		1,597
Issuance of common stock under Equity Incentive Plans, value	347	2	345	0	0	0
Other	0
Repurchase of common stock	(873)	0	0	0	0	(873)
Net loss	(55,054)	0	0	(55,054)	0	0
Unrealized gain (loss) on investments	8	0	0	0	8	0
Balance, value at Jun. 30, 2013	$ 215,084	$ 514	$ 1,170,928	$ (954,886)	$ 31	$ (1,503)
Balance, shares at Jun. 30, 2013		513,972