Risk Management and Use of Derivative Financial Instruments (Details 7)	6 Months Ended
	Jun. 30, 2014
Hellweg Die Profi-Baumärkte GmbH & Co. KG
Concentration Risk
Concentration Risk Percentage	7.00%
Carrefour France SAS
Concentration Risk
Concentration Risk Percentage	5.00%
U-Haul Moving Partners Inc. and Mercury Partners, LP
Concentration Risk
Concentration Risk Percentage	5.00%
Customer concentration risk
Concentration Risk
Concentration Risk Percentage	17.00%
Retail Industry
Concentration Risk
Concentration Risk Percentage	22.00%
Electronics Industry
Concentration Risk
Concentration Risk Percentage	10.00%
All other Industry
Concentration Risk
Concentration Risk Percentage	68.00%
Office
Concentration Risk
Concentration Risk Percentage	25.00%
Industrial
Concentration Risk
Concentration Risk Percentage	25.00%
Warehouse/Distribution
Concentration Risk
Concentration Risk Percentage	20.00%
Retail
Concentration Risk
Concentration Risk Percentage	16.00%
All Other
Concentration Risk
Concentration Risk Percentage	14.00%
US
Concentration Risk
Concentration Risk Percentage	66.00%
International
Concentration Risk
Concentration Risk Percentage	34.00%
Europe
Concentration Risk
Concentration Risk Percentage	33.00%
Germany
Concentration Risk
Concentration Risk Percentage	12.00%
Other Europe
Concentration Risk
Concentration Risk Percentage	21.00%
Other International
Concentration Risk
Concentration Risk Percentage	1.00%