Income Taxes (Schedule Of Income Tax (Provisions) Benefits Attributable To Income From Continuing Operations) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Income Taxes [Abstract]
U.S. federal	$ (8,158)
U.S. state	(3,674)	(2,398)
Current income tax (provision) benefit	(11,832)	(2,398)
U.S. federal	(105,865)	39,880
U.S. state	(6)	10,425
Deferred income tax (provision) benefit	(105,871)	50,305
Income tax (provision) benefit	$ (117,703)	$ 47,907