Noncash Investing and Financing Activities (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Supplemental Cash Flow Information [Abstract]
Accrued dividends and distributions payable	$ 50,576,000	$ 46,180,000
Additions to real estate assets accrued but not yet paid	19,162,000	18,798,000
Transfer of Citadel Mall in settlement of mortgage debt obligation, net	$ 43,909,000	$ 0