Accumulated Other Comprehensive Income (Loss) Attributable to Federated Hermes, Inc. Shareholders (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Accumulated Other Comprehensive Income (Loss), net of tax [Rollforward]
Balance, beginning of period	$ 1,041,280	$ 857,121
Balance, end of period	1,151,576	950,497
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)	(9,333)	(13,670)
Balance, end of period	$ (9,582)	$ (28,287)