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Investment in Unconsolidated Affiliates (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Apr. 01, 2021	Mar. 31, 2021
Investments in and Advances to Affiliates [Line Items]
Company's share in the earnings of LSV	$ 137,572	$ 117,134	$ 151,891
Distributions received from LSV	131,170	125,534	148,936
LSV Asset Management
Investments in and Advances to Affiliates [Line Items]
Ownership interest in LSV				38.70%	38.80%
Total investment in LSV	107,918
Company's share in the earnings of LSV	137,572	117,134	151,891
Distributions received from LSV	$ 131,170	$ 125,534	$ 148,936