Equity Investment in Real Estate and the Managed REITs (Details 4) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Equity Method Investment Summarized Financial Information Income Statement
Impairment charge	$ (5,294)	$ 0	$ 1,365
Combined Equity Investments
Equity Method Investment Summarized Financial Information Income Statement
Revenues	117,278	108,242	118,819
Expenses	(50,907)	(64,453)	(75,992)
Impairment charge	0	0	(8,602)
Income from continuing operations	66,371	43,789	34,225
Net income attributable to the Managed REITs	15,762	79,591	34,225
Managed REITs
Equity Method Investment Summarized Financial Information Income Statement
Revenues	796,637	860,983	734,870
Expenses	(701,830)	(759,435)	(611,417)
Income from continuing operations	94,807	101,548	123,453
Net income attributable to the Managed REITs	$ 104,342	$ 128,455	$ 116,560