Consolidated Statements of Stockholders' Equity (Unaudited) (USD $) In Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Gain	Treasury Stock
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	5,728	0	5,728	0	0	0
Issuance of common stock under Equity Incentive Plans, shares		1,900
Issuance of common stock under Equity Incentive Plans, value	874	2	872	0	0	0
Repurchase of common stock	(873)	0	0	0	0	(873)
Net loss	(86,712)	0	0	(86,712)	0	0
Unrealized gain on investments	15	0	0	0	15	0
Balance, value at Sep. 30, 2013	185,710	514	1,173,205	(986,544)	38	(1,503)
Balance, shares at Sep. 30, 2013		514,275
Balance, value at Dec. 31, 2013	170,163	514	1,175,108	(1,003,958)	2	(1,503)
Balance, shares at Dec. 31, 2013		514,349
Stock-based compensation	5,584	0	5,584	0	0	0
Issuance of common stock under Equity Incentive Plans, shares		1,767
Issuance of common stock under Equity Incentive Plans, value	325	2	323	0	0	0
Repurchase of common stock	(887)	0	0	0	0	(887)
Net loss	(97,361)	0	0	(97,361)	0	0
Unrealized gain on investments	0
Balance, value at Sep. 30, 2014	$ 77,824	$ 516	$ 1,181,015	$ (1,101,319)	$ 2	$ (2,390)
Balance, shares at Sep. 30, 2014		516,116