TAXES - Income Tax Expense (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021
Current income taxes
Federal	$ (4.2)	$ (6.5)	$ 20.8	$ (0.5)
State	6.0	2.2	7.7	1.7
Total	1.8	(4.3)	28.5	1.2
Deferred income taxes
Federal	50.9	61.3	55.4	94.0
State	(1.6)	1.6	1.4	8.6
Total	49.3	62.9	56.8	102.6
Investment Tax Credits
Deferral	0.0	0.0	2.7	0.4
Amortization	(1.6)	(1.4)	(4.9)	(4.4)
Total	(1.6)	(1.4)	(2.2)	(4.0)
Income tax expense	$ 49.5	$ 57.2	$ 83.1	$ 99.8
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Federal statutory income tax rate	21.00%	21.00%	21.00%	21.00%
Effect of:
COLI policies	(1.30%)	(1.00%)	(1.00%)	(1.00%)
State income taxes	0.70%	0.50%	0.70%	0.80%
Flow through depreciation for plant-related differences	(5.60%)	(5.70%)	(5.80%)	(5.90%)
Federal tax credits	(3.70%)	(3.10%)	(3.80%)	(3.10%)
Non-controlling interest	(0.30%)	(0.30%)	(0.30%)	(0.30%)
AFUDC equity	(0.50%)	(0.60%)	(0.50%)	(0.60%)
Amortization of federal investment tax credits	(0.20%)	(0.40%)	(0.20%)	(0.40%)
Stock compensation	0.00%	0.00%	(0.20%)	0.00%
Officer compensation limitation	0.20%	0.50%	0.20%	0.50%
Other	0.00%	0.30%	(0.20%)	(0.30%)
Effective income tax rate	10.30%	11.20%	9.90%	10.70%
Evergy Kansas Central
Current income taxes
Federal	$ 22.3	$ 25.6	$ 59.1	$ 45.1
State	3.2	1.1	2.3	2.6
Total	25.5	26.7	61.4	47.7
Deferred income taxes
Federal	(8.3)	(3.6)	(38.7)	(2.6)
State	(0.6)	0.6	1.2	3.5
Total	(8.9)	(3.0)	(37.5)	0.9
Investment Tax Credits
Deferral	0.0	0.0	2.7	0.4
Amortization	(1.1)	(1.1)	(3.1)	(3.3)
Total	(1.1)	(1.1)	(0.4)	(2.9)
Income tax expense	$ 15.5	$ 22.6	$ 23.5	$ 45.7
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Federal statutory income tax rate	21.00%	21.00%	21.00%	21.00%
Effect of:
COLI policies	(2.70%)	(1.70%)	(2.00%)	(1.70%)
State income taxes	0.70%	0.50%	0.40%	0.80%
Flow through depreciation for plant-related differences	(3.60%)	(3.60%)	(3.90%)	(3.70%)
Federal tax credits	(7.70%)	(5.20%)	(8.00%)	(5.20%)
Non-controlling interest	(0.60%)	(0.50%)	(0.60%)	(0.50%)
AFUDC equity	(0.70%)	(0.50%)	(0.70%)	(0.60%)
Amortization of federal investment tax credits	0.10%	(0.50%)	0.10%	(0.50%)
Stock compensation	0.00%	0.00%	(0.20%)	(0.10%)
Officer compensation limitation	0.00%	0.40%	0.00%	0.30%
Other	0.10%	0.20%	(0.30%)	(0.80%)
Effective income tax rate	6.60%	10.10%	5.80%	9.00%
Evergy Metro
Current income taxes
Federal	$ (22.5)	$ (24.2)	$ (20.0)	$ 23.9
State	2.1	2.0	3.2	3.2
Total	(20.4)	(22.2)	(16.8)	27.1
Deferred income taxes
Federal	54.3	49.5	73.9	18.5
State	(0.1)	(0.4)	(0.1)	(0.8)
Total	54.2	49.1	73.8	17.7
Investment Tax Credits
Amortization	(0.6)	(0.4)	(1.8)	(1.1)
Income tax expense	$ 33.2	$ 26.5	$ 55.2	$ 43.7
Effective Income Tax Rate Reconciliation, Percent [Abstract]
Federal statutory income tax rate	21.00%	21.00%	21.00%	21.00%
Effect of:
COLI policies	(0.10%)	(0.10%)	(0.10%)	(0.20%)
State income taxes	0.70%	0.60%	0.60%	0.60%
Flow through depreciation for plant-related differences	(6.30%)	(7.80%)	(6.50%)	(8.00%)
Federal tax credits	(0.10%)	(0.60%)	(0.10%)	(0.60%)
AFUDC equity	(0.40%)	(0.70%)	(0.40%)	(0.70%)
Amortization of federal investment tax credits	(0.50%)	(0.40%)	(0.60%)	(0.40%)
Stock compensation	0.00%	0.00%	(0.20%)	0.00%
Officer compensation limitation	0.40%	0.90%	0.50%	0.90%
Other	0.00%	(0.20%)	(0.10%)	0.00%
Effective income tax rate	14.70%	12.70%	14.10%	12.60%