Commitments and Contingencies (Details)	12 Months Ended	1 Months Ended	12 Months Ended			1 Months Ended
	Dec. 31, 2012 USD ($) item	May 31, 2010 Opry Mills Mall Limited Partnership USD ($)	Dec. 31, 2012 Mazeikiu Nafta USD ($)	Dec. 31, 2012 Commitments to fund certain limited partnerships or subsidiaries USD ($)	Apr. 02, 2012 Commitments to fund certain limited partnerships or subsidiaries Subsidiaries Term Credit Agreement USD ($)	Apr. 30, 2012 Commitments to fund certain limited partnerships or subsidiaries Subsidiaries Five-Year Agreement	Apr. 02, 2012 Commitments to fund certain limited partnerships or subsidiaries Subsidiaries Five-Year Agreement USD ($)	Apr. 02, 2012 Commitments to fund certain limited partnerships or subsidiaries Subsidiaries Euro Facility Agreement EUR (€)
Legal, Guarantees and Indemnifications
Amount paid in exchange for dismissal of class claims	$ 550,000
Number of non-class claim pending	1
Value of damages sought		200,000,000	125,000,000
Amount of coverage for damages contended by the insurers		50,000,000
Difference amount of damages sought by the client		150,000,000
Estimated exposure with respect to contractual contingent guarantees for premium payments owed by clients	104,000,000
Maximum potential funding under commitments				51,000,000	450,000,000		400,000,000	650,000,000
Term of credit agreement						5 years
Commitments funded				$ 11,000,000