Comprehensive Loss (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Components of comprehensive loss, net of tax [Abstract]
Net loss	$ (62,365,000)	$ (33,875,000)	$ (168,317,000)	$ (89,871,000)
Change in net unrealized gain (loss) on marketable securities	(827,000)	131,000	760,000	(1,219,000)
Total comprehensive loss	(63,192,000)	(33,744,000)	(167,557,000)	(91,090,000)
Change in net unrealized gain (loss) on marketable securities, net of tax effect	$ 600,000		$ (500,000)