Summary of Significant Accounting Policies (Details 3) (USD $)	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2011
Revenue Recognition and Contingent Liabilities - Special Situations Platform Subsidiaries
Gain on sale of net assets	$ 8,000,000
Analysis of the changes in the cumulative adjustments
Balance at the beginning of the period	(1,853,000)	(740,000)
Aggregate adjustment for the year resulting from translation adjustments and gains and losses on certain hedge transactions	1,319,000	(1,113,000)
Balance at the end of the period	(534,000)	(1,853,000)
Foreign currency transaction gain and losses	200,000	(500,000)
Foreign currency translation gain (loss) included in accumulated other comprehensive income (loss) relating to the Euro-denominated debt	(300,000)	300,000
Income Taxes
Threshold of subsidiary ownership percentage used to determine the consolidated group for filing federal income tax returns	80.00%
Special Situations Platform
Revenue Recognition and Contingent Liabilities - Special Situations Platform Subsidiaries
Internal rate of return (as a percent)	20.00%
Payment to manager on basis of remaining net cash flows (as a percent)	37.50%
Liability related to the management agreement	$ 4,900,000	$ 400,000