Significant Accounting Policies - Basis of Presentation (Details) - USD ($)		Sep. 30, 2022	Dec. 31, 2021
Variable Interest Entity [Line Items]
Investments	[1]	$ 70,991,000	$ 95,506,000
Equity method investment, assets		279,034,000	264,300,000
Maximum loss exposure		1,400,000	2,200,000
Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Equity method investment, assets		1,100,000	1,800,000
Equity Method Investment, Nonconsolidated Investee or Group of Investees | VIEs that are not consolidated
Variable Interest Entity [Line Items]
Equity method investment, assets		178,800,000	$ 234,700,000
Equity Method Investment, Nonconsolidated Investee or Group of Investees | Pzena International Value Fund
Variable Interest Entity [Line Items]
Investments		$ 11,000,000.0

[1] Asset and liability amounts in parentheses represent the aggregated balances at September 30, 2022 and December 31, 2021 attributable to Pzena U.S. Best Ideas (GP), LLC and Pzena Global Best Ideas (GP), LLC, which were variable interest entities as of September 30, 2022 and December 31, 2021. Asset and liability amounts in parentheses at September 30, 2022 are also attributable to Pzena 320 Fund (GP), LLC and Pzena 320 Fund, LP. Asset and liability amounts in parentheses at December 31, 2021 are also attributable to Pzena Global Focus Value Fund.