Investment In Unconsolidated Affiliate (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Investments in and Advances to Affiliates [Line Items]
Distributions received from unconsolidated affiliate			$ 123,663	$ 138,216
Company's share in the earnings of equity method investee	$ 37,609	$ 41,726	$ 112,758	123,406
LSV Asset Management
Investments in and Advances to Affiliates [Line Items]
Equity method investment, ownership percentage	38.90%		38.90%
Total investment in equity method investee	$ 41,437		$ 41,437
Distributions received from unconsolidated affiliate			123,663	138,216
Company's share in the earnings of equity method investee	$ 37,609	$ 41,726	$ 112,758	$ 123,406

Amount of distribution received from equity method investee for return on investment, classified as operating activities. Excludes distribution for return of investment, classified as investing activities.

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