Consolidation - Consolidated Federated Fund VIEs (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Variable Interest Entities [Line Items]
Consolidated VIE assets	$ 2,003,726	$ 1,880,131
Less: Liabilities	637,849	626,765
Variable Interest Entity, Primary Beneficiary
Variable Interest Entities [Line Items]
Less: Liabilities	100	100
Less: Redeemable Noncontrolling Interest in Subsidiaries	0	9,300
Federated Hermes' Net Interest in Federated Hermes Fund VIE	6,900	4,200
Variable Interest Entity, Primary Beneficiary | Investments—Consolidated Investment Companies
Variable Interest Entities [Line Items]
Consolidated VIE assets	6,800	13,300
Variable Interest Entity, Primary Beneficiary | Other Assets
Variable Interest Entities [Line Items]
Consolidated VIE assets	$ 200	$ 300