Earnings (Loss) Per Share (Computation Of Basic And Diluted Earnings/Loss Per Common Share) (Details) (USD $) In Thousands, except Per Share data	3 Months Ended		9 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011	Sep. 30, 2010
Earnings (Loss) Per Share [Abstract]
Net income (loss), basic	$ (17,653)	$ 217,334	$ (27,101)	$ 218,008
Interest expense on convertible debt	0	2,599	0	7,797
Amortization of deferred offering costs related to the convertible debt	0	411	0	1,232
Net income (loss), diluted	$ (17,653)	$ 220,344	$ (27,101)	$ 227,037
Basic weighted-average shares outstanding	112,290	102,110	111,358	101,660
Stock options	0	2,103	0	2,095
Potentially issuable restricted common stock	0	171	0	171
Potentially issuable common stock for ESPP purchases		551	0	552
Common stock issuable under convertible debt	0	26,343	0	26,343
Fully diluted weighted-average shares	112,290	131,278	111,358	130,821
Basic earnings (loss) per common share	$ (0.16)	$ 2.13	$ (0.24)	$ 2.14
Diluted earnings (loss) per common share	$ (0.16)	$ 1.68	$ (0.24)	$ 1.74