Investment In Unconsolidated Affiliate (Statement of Operations) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Schedule of Equity Method Investments [Line Items]
Revenues	$ 400,646	$ 409,586	$ 815,408	$ 810,406
Equity Method Investment, Nonconsolidated Investee | LSV Asset Management
Schedule of Equity Method Investments [Line Items]
Revenues	94,648	123,017	194,644	243,932
Net income	$ 72,847	$ 97,271	$ 149,744	$ 193,219