Consolidation - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Variable Interest Entity [Line Items]
Accounts receivable from Federated Funds	$ 35,000,000	$ 27,400,000
Fee Waivers	358,200,000	345,500,000
Financial Support, Fee Waivers
Variable Interest Entity [Line Items]
Money market funds	242,900,000	222,100,000
Financial Support, Capital Contributions
Variable Interest Entity [Line Items]
Money market funds	0	0
Non-Consolidated Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
AUM for nonconsolidated Federated Funds		55,800,000
Accounts Receivable | Non-Consolidated Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Federated's maximum risk of loss in non-consolidated investment companies	$ 16,200,000	2,300,000
Investments—Affiliates and Other | Non-Consolidated Variable Interest Entity, Not Primary Beneficiary
Variable Interest Entity [Line Items]
Federated's maximum risk of loss in non-consolidated investment companies		$ 900,000