Risk Management and Use of Derivative Financial Instruments (Details 8)	12 Months Ended
	Dec. 31, 2013
Concentration Risk
Concentration risk percentage	100.00%
Metro Ag Europe
Concentration Risk
Concentration risk percentage	11.00%
Retail Industry
Concentration Risk
Concentration risk percentage	25.00%
Media Printing And Publishing
Concentration Risk
Concentration risk percentage	13.00%
Grocery
Concentration Risk
Concentration risk percentage	13.00%
Other Industry
Concentration Risk
Concentration risk percentage	49.00%
Office facility
Concentration Risk
Concentration risk percentage	32.00%
Warehouse/Distribution
Concentration Risk
Concentration risk percentage	23.00%
Retail Property
Concentration Risk
Concentration risk percentage	21.00%
Industrial Property
Concentration Risk
Concentration risk percentage	16.00%
Other Property
Concentration Risk
Concentration risk percentage	8.00%
Us
Concentration Risk
Concentration risk percentage	61.00%
Texas
Concentration Risk
Concentration risk percentage	10.00%
Other Us
Concentration Risk
Concentration risk percentage	51.00%
International
Concentration Risk
Concentration risk percentage	39.00%
Italy
Concentration Risk
Concentration risk percentage	11.00%
Other international
Concentration Risk
Concentration risk percentage	28.00%