Summary of Significant Accounting Policies (Details 2) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Discontinued Operations
Gain (loss) upon acquisition of controlling interests, sale or disposal of assets and interests in unconsolidated entities and impairment charge on investment in unconsolidated entities, net	$ 107,515	$ 510,030	$ 216,629
Sale of Consolidated Properties
Discontinued Operations
Gain (loss) upon acquisition of controlling interests, sale or disposal of assets and interests in unconsolidated entities and impairment charge on investment in unconsolidated entities, net	$ 64,800	$ 21,100	$ (42,400)
Net gain (loss) upon acquisition of controlling interests, and on sale or disposal of assets and interests in unconsolidated entities, per diluted share (in dollars per share)	$ 0.18	$ 0.06	$ (0.12)