ORGANIZATION AND BASIS OF PRESENTATION - Other Income And Expense (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Entity Information [Line Items]
Non-service cost component of net benefit cost	$ (10.2)	$ (12.8)	$ (46.5)	$ (41.4)
Other	(6.5)	(6.4)	(18.0)	(17.5)
Other expense	(16.7)	(19.2)	(64.5)	(58.9)
Evergy Kansas Central
Entity Information [Line Items]
Non-service cost component of net benefit cost	(4.2)	(3.4)	(13.6)	(11.1)
Other	(6.3)	(5.9)	(16.2)	(15.1)
Other expense	(10.5)	(9.3)	(29.8)	(26.2)
Evergy Metro
Entity Information [Line Items]
Non-service cost component of net benefit cost	(2.2)	(5.8)	(21.8)	(19.8)
Other	(0.3)	(0.5)	(1.3)	(2.0)
Other expense	$ (2.5)	$ (6.3)	$ (23.1)	$ (21.8)