Mortgage and Other Indebtedness, Covenants (Details) (USD $)	12 Months Ended
	Dec. 31, 2013
Non Recourse Loans On Operating Properties [Member]
Debt Instrument [Line Items]
Debt default threshold	$ 50,000,000
Recourse Term Loans on Operating Properties [Member]
Debt Instrument [Line Items]
Debt default threshold	$ 150,000,000
Senior Unsecured Notes [Member] | Minimum [Member] | Forecast [Member]
Debt Instrument [Line Items]
Secured debt to total assets	40.00%
Debt Covenant Requirement [Member] | Senior Unsecured Notes [Member]
Debt Instrument [Line Items]
Total debt to total assets	60.00%
Secured debt to total assets	45.00%
Total unencumbered assets to unsecured debt	150.00%
Consolidated income available for debt service to annual debt service charge	150.00%
Debt Covenant Requirement [Member] | Debt to total asset value [Member]
Debt Instrument [Line Items]
Debt to asset ratio, description	< 60%
Debt to asset ratio (percent)	60.00%
Debt Covenant Requirement [Member] | Ratio of unencumbered asset value to unsecured indebtedness [Domain]
Debt Instrument [Line Items]
Debt to asset ratio, description	> 1.60x
Debt to asset ratio (percent)	160.00%
Debt Covenant Requirement [Member] | Ratio of unencumbered NOI to unsecured interest expense [Member]
Debt Instrument [Line Items]
Debt to asset ratio, description	> 1.75x
Debt to asset ratio (percent)	175.00%
Debt Covenant Requirement [Member] | Ratio of EBITDA to fixed charges (debt service) [Member]
Debt Instrument [Line Items]
Debt to asset ratio, description	> 1.50x
Debt to asset ratio (percent)	150.00%
Debt Covenant Ratios Actual [Member] | Senior Unsecured Notes [Member]
Debt Instrument [Line Items]
Total debt to total assets	54.70%
Secured debt to total assets	41.30%
Total unencumbered assets to unsecured debt	244.90%
Consolidated income available for debt service to annual debt service charge	323.00%
Debt Covenant Ratios Actual [Member] | Debt to total asset value [Member]
Debt Instrument [Line Items]
Debt to asset ratio, description	0.5162
Debt to asset ratio (percent)	51.60%
Debt Covenant Ratios Actual [Member] | Ratio of unencumbered asset value to unsecured indebtedness [Domain]
Debt Instrument [Line Items]
Debt to asset ratio, description	2.51x
Debt to asset ratio (percent)	251.00%
Debt Covenant Ratios Actual [Member] | Ratio of unencumbered NOI to unsecured interest expense [Member]
Debt Instrument [Line Items]
Debt to asset ratio, description	6.15x
Debt to asset ratio (percent)	615.00%
Debt Covenant Ratios Actual [Member] | Ratio of EBITDA to fixed charges (debt service) [Member]
Debt Instrument [Line Items]
Debt to asset ratio, description	2.20x
Debt to asset ratio (percent)	220.00%