Net Income (Loss) Per Share Attributable To Common Stockholders (Reconciliation Of Earnings Attributable To Common Stockholders, Basic And Diluted) (Details) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Statement Operating Activities Segment [Line Items]
Income (loss) as reported, Continuing Operations	$ 458,762	$ 511,945	$ (141,983)
Income (loss) as reported, Discontinued Operations	423,152	134,050	99,716
Income (loss) as reported	834,489	605,208	(52,106)
Net income attributable to noncontrolling interests	(47,425)	(40,787)	(9,839)
Participating basic earnings	(15,178)	(13,896)	(196)
Basic income (loss) attributable to common stockholders	819,311	591,312	(52,302)
Reallocation of participating earnings	385	180
Diluted income (loss) attributable to common stockholders	819,696	591,492	(52,302)
Segment, Continuing Operations [Member]
Statement Operating Activities Segment [Line Items]
Income (loss) as reported, Continuing Operations	411,337	471,158	(151,822)
Participating basic earnings	(7,482)	(10,818)	(571)
Basic income (loss) attributable to common stockholders	403,855	460,340	(152,393)
Reallocation of participating earnings	190	140
Diluted income (loss) attributable to common stockholders	404,045	460,480	(152,393)
Segment, Discontinued Operations [Member]
Statement Operating Activities Segment [Line Items]
Income (loss) as reported, Discontinued Operations	423,152	134,050	99,716
Participating basic earnings	(7,696)	(3,078)	375
Basic income (loss) attributable to common stockholders	415,456	130,972	100,091
Reallocation of participating earnings	195	40
Diluted income (loss) attributable to common stockholders	$ 415,651	$ 131,012	$ 100,091