Net Income (Loss) Per Share (Reconciliation Of Earnings Attributable To Common Stockholders, Basic And Diluted) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Statement Operating Activities Segment [Line Items]
Income (loss) from continuing operations attributable to parent	$ (82,409)	$ 248,602	$ 121,515	$ 177,314
Income (loss) from discontinued operations, net of tax, attributable to parent	12,017	(3,025)	22,712	416,857
Income (loss) as reported	(70,392)	245,577	144,227	594,171
Participating basic earnings	(265)	(4,847)	(2,176)	(10,849)
Basic income attributable to common stockholders	(70,657)	240,730	142,051	583,322
Reallocation of participating earnings	0	164	154	271
Diluted income attributable to common stockholders	(70,657)	240,894	142,205	583,593
Continuing Operations [Member]
Statement Operating Activities Segment [Line Items]
Income (loss) from continuing operations attributable to parent	(82,409)	248,602	121,515	177,314
Participating basic earnings	(265)	(4,847)	(1,833)	(3,238)
Basic income attributable to common stockholders	(82,674)	243,755	119,682	174,076
Reallocation of participating earnings	0	164	130	81
Diluted income attributable to common stockholders	(82,674)	243,919	119,812	174,157
Discontinued Operations [Member]
Statement Operating Activities Segment [Line Items]
Income (loss) from discontinued operations, net of tax, attributable to parent	12,017	(3,025)	22,712	416,857
Participating basic earnings	0	0	(343)	(7,611)
Basic income attributable to common stockholders	12,017	(3,025)	22,369	409,246
Reallocation of participating earnings	0	0	24	190
Diluted income attributable to common stockholders	$ 12,017	$ (3,025)	$ 22,393	$ 409,436