CONSOLIDATED STATEMENTS OF COMPREHENSIVE LOSS (USD $) In Thousands, unless otherwise specified	3 Months Ended					12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Net loss	$ (78,151)	$ (41,134)	$ 1,309	$ 3,949	$ 2,404	$ (100,060)	$ (33,472)	$ (19,586)
Unrealized hedging gains, net of provision for (benefit from) income taxes of $-, $161 and $(161)						(298)	298
Net change in unrealized gains and losses on marketable securities, net of benefit from (provision for) income taxes of ($923) in 2010, $6,543 in 2011 and $8,487 in 2012						(15,760)	(12,152)	1,711
Other comprehensive income (loss)						(16,058)	(11,854)	1,711
Comprehensive loss						$ (116,118)	$ (45,326)	$ (17,875)