Fair Value Measurements for Operating Entities and Consolidated Funds Fair Value Inputs, Unobservable Inputs, Quantitative Information (Details) (Operating Entities, Level 3, USD $) In Thousands, unless otherwise specified					6 Months Ended			6 Months Ended
	Jun. 30, 2013	Jun. 30, 2013 Other Assets and Liabilities		Jun. 30, 2013 Income Approach and Market Approach Valuation Techniques Common and Preferred Stock	Jun. 30, 2013 Income Approach and Market Approach Valuation Techniques Common and Preferred Stock Minimum	Jun. 30, 2013 Income Approach and Market Approach Valuation Techniques Common and Preferred Stock Maximum	Jun. 30, 2013 Market Approach Valuation Technique Warrants and Rights	Jun. 30, 2013 Market Approach Valuation Technique Warrants and Rights Minimum	Jun. 30, 2013 Market Approach Valuation Technique Warrants and Rights Maximum	Jun. 30, 2013 Fair Value, Measurements, Recurring Warrants and Rights	Dec. 31, 2012 Fair Value, Measurements, Recurring Warrants and Rights
Fair Value Inputs, Assets and Liabilities, Quantitative Information [Line Items]
DCF discount rate					15.00%	25.00%
Market multiple					9	10
Volatility								20.00%	150.00%
Investments at fair value	$ 4,742			$ 2,606			$ 2,136			$ 2,136	$ 1,713
Assets and liabilities at fair value	$ 233,292	$ 228,550	[1]

[1] Quantitative disclosures of unobservable inputs and assumptions are not required for investments for which NAV per share is used as a practical expedient to determine fair value, as their redemption features rather than observability of inputs cause them to be classified as a level 3 type asset within the fair value hierarchy. In addition, the fair value of the Consolidated Funds' investments are determined based on net asset value and therefore quantitative disclosures are not included in the table above.