Redeemable Noncontrolling Interest in Subsidiaries (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Increase (Decrease) in Temporary Equity [Roll Forward]
Temporary equity, beginning balance	$ 212,086	$ 182,513
Net Income (Loss)	(913)	65
Other Comprehensive Income (Loss), net of tax	(11,454)	3,714
Subscriptions—Redeemable Noncontrolling Interest Holders	5,577	42
Consolidation/(Deconsolidation)	(4,019)
Stock Award Activity	2,153	2,126
Distributions to Noncontrolling Interest in Subsidiaries	(6,039)	(2,260)
Change in Estimated Redemption Value of Redeemable Noncontrolling Interests	1,870
Temporary equity, ending balance	199,261	186,200
Consolidated Investment Companies
Increase (Decrease) in Temporary Equity [Roll Forward]
Temporary equity, beginning balance	19,872	11,626
Net Income (Loss)	(2,802)	678
Subscriptions—Redeemable Noncontrolling Interest Holders	5,577	42
Consolidation/(Deconsolidation)	(4,019)
Distributions to Noncontrolling Interest in Subsidiaries	(6,039)	(2,260)
Temporary equity, ending balance	12,589	10,086
Hermes
Increase (Decrease) in Temporary Equity [Roll Forward]
Temporary equity, beginning balance	192,214	170,887
Net Income (Loss)	1,889	(613)
Other Comprehensive Income (Loss), net of tax	(11,454)	3,714
Stock Award Activity	2,153	2,126
Change in Estimated Redemption Value of Redeemable Noncontrolling Interests	1,870
Temporary equity, ending balance	$ 186,672	$ 176,114