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	1,718	0	1,718	0	0	0
Issuance of common stock under Equity Incentive Plans, shares		553
Issuance of common stock under Equity Incentive Plans, value	52	1	51	0	0	0
Other	(136)	0	(136)	0	0	0
Repurchase of common stock	(285)	0	0	0	0	(285)
Net loss	(29,868)	0	0	(29,868)	0	0
Unrealized gain (loss) on investments	(78)	0	0	0	(78)	0
Balance, value at Mar. 31, 2012	268,971	481	1,088,666	(819,489)	(57)	(630)
Balance, shares at Mar. 31, 2012		480,942
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	2,109	0	2,109	0	0	0
Issuance of common stock under Equity Incentive Plans, shares		1,460
Issuance of common stock under Equity Incentive Plans, value	249	2	247	0	0	0
Other	0
Repurchase of common stock	(873)	0	0	0	0	(873)
Net loss	(25,974)	0	0	(25,974)	0	0
Unrealized gain (loss) on investments	19	0	0	0	19	0
Balance, value at Mar. 31, 2013	$ 242,208	$ 514	$ 1,168,961	$ (925,806)	$ 42	$ (1,503)
Balance, shares at Mar. 31, 2013		513,835