Risk Management and Use of Derivative Financial Instruments (Details 7)	12 Months Ended
	Dec. 31, 2013
Retail Industry
Concentration Risk
Concentration Risk Percentage	19.00%
Other Industry
Concentration Risk
Concentration Risk Percentage	81.00%
Office
Concentration Risk
Concentration Risk Percentage	32.00%
Industrial
Concentration Risk
Concentration Risk Percentage	18.00%
Warehouse/Distribution
Concentration Risk
Concentration Risk Percentage	16.00%
Retail
Concentration Risk
Concentration Risk Percentage	13.00%
All Other
Concentration Risk
Concentration Risk Percentage	21.00%
CA
Concentration Risk
Concentration Risk Percentage	10.00%
US Other
Concentration Risk
Concentration Risk Percentage	60.00%
US
Concentration Risk
Concentration Risk Percentage	70.00%
Europe
Concentration Risk
Concentration Risk Percentage	30.00%