PENSION PLANS AND POST-RETIREMENT BENEFITS - Narrative (Details) - USD ($)	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Settlement and special termination (gain) loss	$ 0	$ (15,900,000)
Contributions by employer	0
Contributions to plans remainder of year	38,600,000
Post-Retirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Settlement and special termination (gain) loss		0
Contributions by employer	400,000
Contributions to plans remainder of year	400,000
Evergy Kansas Central | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Settlement and special termination (gain) loss	0	400,000
Contributions by employer	0
Contributions to plans remainder of year	11,700,000
Evergy Kansas Central | Post-Retirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Settlement and special termination (gain) loss		0
Contributions by employer	200,000
Contributions to plans remainder of year	200,000
Evergy Metro | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Settlement and special termination (gain) loss	0	(16,300,000)
Contributions by employer	0
Contributions to plans remainder of year	26,900,000
Evergy Metro | Post-Retirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Settlement and special termination (gain) loss		$ 0
Contributions by employer	200,000
Contributions to plans remainder of year	$ 200,000
Wolf Creek
Defined Benefit Plan Disclosure [Line Items]
Jointly owned utility plant, proportionate ownership share	94.00%
Wolf Creek | Evergy Kansas South Inc
Defined Benefit Plan Disclosure [Line Items]
Jointly owned utility plant, proportionate ownership share	47.00%
Wolf Creek | Evergy Metro
Defined Benefit Plan Disclosure [Line Items]
Jointly owned utility plant, proportionate ownership share	47.00%