Accumulated Other Comprehensive Income (Loss) Attributable to Federated Hermes, Inc. Shareholders (Details) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019
Accumulated Other Comprehensive Income (Loss), net of tax [Rollforward]
Balance, beginning of period	$ 1,041,280	$ 857,121
Balance, end of period	1,086,667	912,528
Foreign Currency Translation Gain (Loss)
Accumulated Other Comprehensive Income (Loss), net of tax [Rollforward]
Balance, beginning of period	(249)	(14,617)
Other Comprehensive Income (Loss)	(25,572)	(1,875)
Balance, end of period	$ (25,821)	$ (16,492)