Non-Controlling Interests (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Noncontrolling Interest [Line Items]
Net Income Attributable to Non-Controlling Interests	$ 22,474	$ 10,651	$ 43,316	$ 11,420
Non-Controlling Interests of Pzena Investment Management, LLC
Noncontrolling Interest [Line Items]
Net Income Attributable to Non-Controlling Interests	22,225	10,417	42,873	11,500
Non-Controlling Interests of Consolidated Subsidiaries
Noncontrolling Interest [Line Items]
Net Income Attributable to Non-Controlling Interests	$ 249	$ 234	$ 443	$ (80)