Goodwill And Other Intangible Assets (Schedule Of Gross Cost And Accumulated Amortization) (Details) (USD $) In Thousands	Sep. 30, 2011	Dec. 31, 2010
Other intangible assets, Gross Cost	$ 63,364	$ 63,217
Other intangible assets, Accumulated Amortization	19,903	15,007
Other intangible assets, Net Carrying Amount	43,461	48,210
Success/Performance Fees [Member]
Other intangible assets, Gross Cost	30,740	30,740
Other intangible assets, Accumulated Amortization	1,450	890
Other intangible assets, Net Carrying Amount	29,290	29,850
Management Fees, Customer Relationships And Non-Compete Agreements [Member]
Other intangible assets, Gross Cost	32,624	32,477
Other intangible assets, Accumulated Amortization	18,453	14,117
Other intangible assets, Net Carrying Amount	$ 14,171	$ 18,360