Noncontrolling Interests and Redeemable Noncontrolling Interests (Details 3) (USD $) In Thousands, except Share data, unless otherwise specified	1 Months Ended		3 Months Ended
	Mar. 31, 2012	Jan. 31, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Mar. 31, 2012 Redeemable Noncontrolling PJV Interest [Member]	Mar. 31, 2011 Redeemable Noncontrolling PJV Interest [Member]	Mar. 31, 2012 Reedemable Noncontrolling Interest [Member]	Dec. 31, 2011 Reedemable Noncontrolling Interest [Member]	Mar. 31, 2012 Noncontrolling Interest [Member]	Dec. 31, 2011 Noncontrolling Interest [Member]	Mar. 31, 2012 Third Party Interests [Member]	Dec. 31, 2011 Third Party Interests [Member]	Mar. 31, 2012 Other Consolidated Subsidiaries [Member]	Dec. 31, 2011 Other Consolidated Subsidiaries [Member]
Redeemable Noncontrolling Interest [Line Items]
Redeemable Noncontrolling Interest, Equity, Carrying Amount	$ 460,373			$ 460,373	$ 456,105			$ 36,596	$ 32,271			$ 30,254	$ 26,036	$ 6,342	$ 6,235
Non-controlling interests										193,296	207,113	188,690	202,833	4,606	4,280
Increase (Decrease) in Redeemable Noncontrolling Preferred Joint Venture Interest
Redeemable noncontrolling preferred joint venture interest		423,834	423,777	423,834		423,834	423,834
Net income attributable to redeemable noncontrolling preferred joint venture interest						5,144	5,085
Distributions to redeemable noncontrolling preferred joint venture interest						(5,201)	(5,200)
Redeemable noncontrolling preferred joint venture interest	423,777			423,777	423,834	423,777	423,719
Payments for Repurchase of Redeemable Noncontrolling Interest			$ 3,475	$ 6,359
Redeemable Noncontrolling Interest, Conversion Rights Exercised for Cash	194,572	30,056			401,324