Real Estate Owned (Details) (USD $) In Thousands, unless otherwise specified	Jun. 30, 2013	Dec. 31, 2012
Summary of carrying amounts for real estate owned (at cost)
Land and Land Improvements	$ 1,265,049	$ 1,907,169
Depreciable property - held and used:
Building and improvements	6,054,933	5,384,971
Furniture, fixtures and equipment	262,999	272,640
Under development:
Under development	432,461	489,795
Real estate owned	8,016,688	8,055,828
Accumulated depreciation	(2,071,649)	(1,924,682)
Total real estate owned, net of accumulated depreciation	5,945,039	6,131,146
Land [Member]
Under development:
Under development	112,091	151,154
Construction in progress [Member]
Under development:
Under development	$ 321,616	$ 339,894