Equity Investments in Real Estate (Details 1) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Ownership interest in equity investments:
Equity investments in real estate	$ 363,727	$ 275,133
C1000 Logistiek Vastgooed B.V
Ownership interest in equity investments:
Ownership interest, percentage	85.00%
Equity investments in real estate	81,853	81,516
State Farm Mutual Automobile Company
Ownership interest in equity investments:
Ownership interest, percentage	50.00%
Equity investments in real estate	21,182	0
Uhaul Moving Partners Inc And Mercury Partners LP
Ownership interest in equity investments:
Ownership interest, percentage	12.00%
Equity investments in real estate	27,367	28,019
Berry Plastics Corporation
Ownership interest in equity investments:
Ownership interest, percentage	50.00%
Equity investments in real estate	17,875	18,529
Tesco plc
Ownership interest in equity investments:
Ownership interest, percentage	49.00%
Equity investments in real estate	17,231	17,487
Hellweg Die Profi Baumarkt Gmbh And Co KG
Ownership interest in equity investments:
Ownership interest, percentage	33.00%
Equity investments in real estate	20,750	22,827
Eroski Sociedad Cooperativa Mallorca
Ownership interest in equity investments:
Ownership interest, percentage	30.00%
Equity investments in real estate	9,649	9,336
Dicks Sporting Goods Inc
Ownership interest in equity investments:
Ownership interest, percentage	45.00%
Equity investments in real estate	4,668	5,010
BPS Partners, LLC
Ownership interest in equity investments:
Ownership interest, percentage	15.00%
Equity investments in real estate	26,767	26,253
Madison Self Storage
Ownership interest in equity investments:
Ownership interest, percentage	85.00%
Equity investments in real estate	22,731	0
Shelborne
Ownership interest in equity investments:
Equity investments in real estate	107,707	63,896
I-Drive Live
Ownership interest in equity investments:
Equity investments in real estate	$ 5,947	$ 2,260