Net Gain (Loss) on Disposition of Partial Interests in Rental Properties (Details 1) (QIC Joint Venture [Member], USD $) In Thousands, unless otherwise specified	Dec. 31, 2013
QIC Joint Venture [Member]
Assets [Abstract]
Real estate, net	$ (920,602)
Cash and equivalents	324,549
Restricted cash and escrowed funds	(4,326)
Notes and accounts receivable, net	(23,201)
Investments in and advances to unconsolidated entities	40,249
Other assets	(90,098)
Total Assets	(673,429)
Liabilities [Abstract]
Mortgage debt and notes payable, nonrecourse	(979,448)
Accounts payable, accrued expenses and other liabilities	(17,446)
Total Liabilities	(996,894)
Equity [Abstract]
Additional paid-in capital	(89,644)
Retained earnings	408,707
Noncontrolling interest	4,402
Total Equity	323,465
Total Liabilities and Equity	$ (673,429)