ORGANIZATION AND BASIS OF PRESENTATION - Other Income And Expense (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Entity Information [Line Items]
Non-service cost component of net benefit cost	$ (4.6)	$ (14.8)
Other	(4.9)	(6.5)
Other expense	(9.5)	(21.3)
Evergy Kansas Central
Entity Information [Line Items]
Non-service cost component of net benefit cost	0.5	(4.0)
Other	(4.2)	(5.9)
Other expense	(3.7)	(9.9)
Evergy Metro
Entity Information [Line Items]
Non-service cost component of net benefit cost	(3.0)	(8.7)
Other	(0.6)	(0.3)
Other expense	$ (3.6)	$ (9.0)