Non-Controlling Interests (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Noncontrolling Interest [Line Items]
Net Income Attributable to Non-Controlling Interests	$ 12,910	$ 13,438	$ 24,330	$ 39,209
Non-Controlling Interests of Pzena Investment Management, LLC
Noncontrolling Interest [Line Items]
Net Income Attributable to Non-Controlling Interests	12,827	13,434	24,327	39,039
Non-Controlling Interests of Consolidated Subsidiaries
Noncontrolling Interest [Line Items]
Net Income Attributable to Non-Controlling Interests	$ 83	$ 4	$ 3	$ 170