Accumulated Other Comprehensive Income (Loss) Attributable to Federated Hermes, Inc. Shareholders (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Accumulated Other Comprehensive Income (Loss), net of tax [Rollforward]
Balance, beginning of period	$ 1,041,280	$ 857,121
Balance, end of period	1,042,933	897,739
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)	(24,859)	7,664
Net Current-Period Other Comprehensive Income (Loss)	(24,859)	7,664
Balance, end of period	$ (25,108)	$ (6,953)