Equity Investment in Real Estate and the Managed REITs (Details 5) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2013 Real Estate Investments	Dec. 31, 2012 Real Estate Investments	Dec. 31, 2013 Schuler A.G. Real Estate Investments	Dec. 31, 2012 Schuler A.G. Real Estate Investments	Dec. 31, 2013 Hellweg Die Profi-Baumarkte GmbH & Co. K.G Real Estate Investments	Dec. 31, 2012 Hellweg Die Profi-Baumarkte GmbH & Co. K.G Real Estate Investments	Dec. 31, 2013 Advanced Micro Devices Real Estate Investments	Dec. 31, 2012 Advanced Micro Devices Real Estate Investments	Dec. 31, 2013 The New York Times Company Real Estate Investments	Dec. 31, 2012 The New York Times Company Real Estate Investments	Dec. 31, 2013 C1000 Logestiek Vastgoed B.V. Real Estate Investments	Dec. 31, 2012 C1000 Logestiek Vastgoed B.V. Real Estate Investments	Dec. 31, 2013 The Upper Deck Company Real Estate Investments	Dec. 31, 2012 The Upper Deck Company Real Estate Investments	Dec. 31, 2013 Del Monte Corporation Real Estate Investments	Dec. 31, 2012 Del Monte Corporation Real Estate Investments	Dec. 31, 2013 Waldaschaff Automotive GmbH and Wagon Automotive Nagold GmbH Real Estate Investments	Dec. 31, 2012 Waldaschaff Automotive GmbH and Wagon Automotive Nagold GmbH Real Estate Investments	Dec. 31, 2013 Builders FirstSource, Inc. Real Estate Investments	Dec. 31, 2012 Builders FirstSource, Inc. Real Estate Investments	Dec. 31, 2013 PetSmart, Inc. Real Estate Investments	Dec. 31, 2012 PetSmart, Inc. Real Estate Investments	Dec. 31, 2013 Consolidated Systems, Inc. Real Estate Investments	Dec. 31, 2012 Consolidated Systems, Inc. Real Estate Investments	Dec. 31, 2012 Wanbishi Archives Co. Ltd.	Dec. 31, 2013 Wanbishi Archives Co. Ltd. Real Estate Investments	Dec. 31, 2012 Wanbishi Archives Co. Ltd. Real Estate Investments	Dec. 31, 2013 U.S. Airways Group, Inc. Real Estate Investments	Dec. 31, 2012 U.S. Airways Group, Inc. Real Estate Investments	Oct. 31, 2013 The Talaria Company (Hinckley)	Dec. 31, 2013 The Talaria Company (Hinckley) Real Estate Investments	Dec. 31, 2012 The Talaria Company (Hinckley) Real Estate Investments	Dec. 31, 2013 SaarOTEC Real Estate Investments	Dec. 31, 2012 SaarOTEC Real Estate Investments
Investments in REITs
Equity method investment, ownership percentage					67.00%		38.00%		33.00%		18.00%		15.00%		50.00%		50.00%		33.00%		40.00%		30.00%		60.00%		3.00%	3.00%		75.00%		30.00%	0.00%		50.00%
Equity investments in real estate	$ 530,020	$ 565,626	$ 185,036	$ 212,481	$ 65,798	$ 62,006	$ 27,923	$ 42,387	$ 22,392	$ 23,667	$ 21,543	$ 20,584	$ 13,673	$ 14,929	$ 7,518	$ 7,198	$ 7,145	$ 8,318	$ 7,267	$ 6,323	$ 4,968	$ 5,138	$ 3,877	$ 3,808	$ 3,176	$ 3,278		$ 395	$ (736)	$ 0	$ 7,995		$ 0	$ 7,702	$ (639)	$ (116)