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
	Mar. 31, 2012	Mar. 31, 2011
Statement Operating Activities Segment [Line Items]
Net income (loss) attributable to common stockholders, Continuing Operations	$ 210,263	$ (76,078)
Net income (loss) attributable to common stockholders, Discontinued Operations	10,695	419,882
Income (loss) as reported	214,619	348,594
Participating basic earnings	(2,448)	(6,140)
Basic income attributable to common stockholders	212,171	342,454
Reallocation of participating earnings	71
Diluted income attributable to common stockholders	212,242	342,454
Continuing Operations [Member]
Statement Operating Activities Segment [Line Items]
Net income (loss) attributable to common stockholders, Continuing Operations	203,924	(71,288)
Participating basic earnings	(2,326)
Basic income attributable to common stockholders	201,598	(71,288)
Reallocation of participating earnings	68
Diluted income attributable to common stockholders	201,666	(71,288)
Discontinued Operations [Member]
Statement Operating Activities Segment [Line Items]
Net income (loss) attributable to common stockholders, Discontinued Operations	10,695	419,882
Participating basic earnings	(122)	(6,140)
Basic income attributable to common stockholders	10,573	413,742
Reallocation of participating earnings	3
Diluted income attributable to common stockholders	$ 10,576	$ 413,742