RATE MATTERS AND REGULATION - Narrative (Details) $ in Millions	1 Months Ended					12 Months Ended
	Dec. 31, 2022 USD ($)	May 31, 2022 USD ($)	Apr. 30, 2022 USD ($)	Jan. 31, 2022 USD ($)	Jun. 30, 2021 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Regulatory Proceedings [Line Items]
Regulatory assets	$ 2,214.3					$ 2,214.3	$ 2,415.2
Regulatory liabilities	$ 2,722.2					$ 2,722.2	2,775.7
Interest rate	5.06%					5.06%
Other regulatory disallowances							0.0	$ 0.0
Purchase power agreement
Regulatory Proceedings [Line Items]
Regulatory liabilities	$ 4.1					$ 4.1	5.8
Regulatory Liability, Amortization Period						5 years
Fuel recovery mechanisms
Regulatory Proceedings [Line Items]
Regulatory liabilities	4.7					$ 4.7	6.5
Regulatory Liability, Amortization Period						1 year
February 2021 winter weather event
Regulatory Proceedings [Line Items]
Regulatory liabilities	37.8					$ 37.8	65.1
Sibley AAO
Regulatory Proceedings [Line Items]
Regulatory liabilities	108.0					$ 108.0	29.3
Regulatory Liability, Amortization Period						4 years
TFR Refund
Regulatory Proceedings [Line Items]
Regulatory liabilities	55.5					$ 55.5	0.0
Pension and post-retirement costs
Regulatory Proceedings [Line Items]
Regulatory assets	137.3					137.3	567.2
Remaining Amounts of Regulatory Assets for which No Return on Investment During Recovery Period is Provided	116.3					116.3
Regulatory asset representing differences between pension and post retirement costs for GAAP and for ratemaking	201.0					201.0
Analog meter unrecovered investment
Regulatory Proceedings [Line Items]
Regulatory assets	12.6					12.6	18.4
Remaining Amounts of Regulatory Assets for which No Return on Investment During Recovery Period is Provided	10.1					$ 10.1
Regulatory Asset, Amortization Period						5 years
February 2021 winter weather event
Regulatory Proceedings [Line Items]
Regulatory assets	430.9					$ 430.9	403.1
Deferred customer programs
Regulatory Proceedings [Line Items]
Regulatory assets	14.3					14.3	18.7
Remaining Amounts of Regulatory Assets for which No Return on Investment During Recovery Period is Provided	7.2					7.2
Fuel recovery mechanisms
Regulatory Proceedings [Line Items]
Regulatory assets	188.5					$ 188.5	202.5
Regulatory Asset, Amortization Period						1 year
Retired generation facility, approved
Regulatory Proceedings [Line Items]
Regulatory assets	146.3					$ 146.3	123.4
Evergy Kansas Central
Regulatory Proceedings [Line Items]
Regulatory assets	711.9					711.9	1,010.9
Regulatory liabilities	1,441.0					1,441.0	1,482.2
Evergy Kansas Central | Purchase power agreement
Regulatory Proceedings [Line Items]
Regulatory liabilities	4.1					4.1	5.8
Evergy Kansas Central | Fuel recovery mechanisms
Regulatory Proceedings [Line Items]
Regulatory liabilities	4.5					4.5	0.0
Evergy Kansas Central | February 2021 winter weather event
Regulatory Proceedings [Line Items]
Regulatory liabilities	0.0					0.0	0.0
Evergy Kansas Central | Sibley AAO
Regulatory Proceedings [Line Items]
Regulatory liabilities	0.0					0.0	0.0
Evergy Kansas Central | TFR Refund
Regulatory Proceedings [Line Items]
Regulatory liabilities	55.5					55.5	0.0
Evergy Kansas Central | Pension and post-retirement costs
Regulatory Proceedings [Line Items]
Regulatory assets	54.9					54.9	265.6
Remaining Amounts of Regulatory Assets for which No Return on Investment During Recovery Period is Provided	54.9					54.9
Regulatory asset representing differences between pension and post retirement costs for GAAP and for ratemaking	(5.6)					(5.6)
Evergy Kansas Central | Analog meter unrecovered investment
Regulatory Proceedings [Line Items]
Regulatory assets	12.6					12.6	18.4
Remaining Amounts of Regulatory Assets for which No Return on Investment During Recovery Period is Provided	10.1					$ 10.1
Regulatory Asset, Amortization Period						5 years
Evergy Kansas Central | February 2021 winter weather event
Regulatory Proceedings [Line Items]
Regulatory assets	121.9					$ 121.9	121.5
Evergy Kansas Central | Deferred customer programs
Regulatory Proceedings [Line Items]
Regulatory assets	6.5					6.5	6.4
Evergy Kansas Central | Fuel recovery mechanisms
Regulatory Proceedings [Line Items]
Regulatory assets	0.0					0.0	120.8
Evergy Kansas Central | Retired generation facility, approved
Regulatory Proceedings [Line Items]
Regulatory assets	0.0					0.0	0.0
Evergy Metro
Regulatory Proceedings [Line Items]
Regulatory assets	373.8					373.8	497.0
Regulatory liabilities	928.1					928.1	1,008.8
Other regulatory disallowances						5.5	0.0	$ 0.0
Evergy Metro | Purchase power agreement
Regulatory Proceedings [Line Items]
Regulatory liabilities	0.0					0.0	0.0
Evergy Metro | Fuel recovery mechanisms
Regulatory Proceedings [Line Items]
Regulatory liabilities	0.2					0.2	6.5
Evergy Metro | February 2021 winter weather event
Regulatory Proceedings [Line Items]
Regulatory liabilities	37.8					37.8	65.1
Evergy Metro | Sibley AAO
Regulatory Proceedings [Line Items]
Regulatory liabilities	0.0					0.0	0.0
Evergy Metro | TFR Refund
Regulatory Proceedings [Line Items]
Regulatory liabilities	0.0					0.0	0.0
Evergy Metro | Pension and post-retirement costs
Regulatory Proceedings [Line Items]
Regulatory assets	0.0					0.0	213.3
Regulatory asset representing differences between pension and post retirement costs for GAAP and for ratemaking	126.2					126.2
Evergy Metro | Analog meter unrecovered investment
Regulatory Proceedings [Line Items]
Regulatory assets	0.0					0.0	0.0
Evergy Metro | February 2021 winter weather event
Regulatory Proceedings [Line Items]
Regulatory assets	0.0					0.0	0.0
Evergy Metro | Deferred customer programs
Regulatory Proceedings [Line Items]
Regulatory assets	6.7					6.7	7.8
Remaining Amounts of Regulatory Assets for which No Return on Investment During Recovery Period is Provided	6.1					6.1
Evergy Metro | Fuel recovery mechanisms
Regulatory Proceedings [Line Items]
Regulatory assets	13.5					13.5	19.8
Evergy Metro | Retired generation facility, approved
Regulatory Proceedings [Line Items]
Regulatory assets	0.0					$ 0.0	0.0
Evergy Metro | Missouri Public Service Commission
Regulatory Proceedings [Line Items]
Public Utilities, Recovery Mechanism Percent for Fuel Cost						0.95
Public Utilities, Recovery Mechanism's Sharing Percentage for Fuel Cost						0.05
Evergy Missouri West | Missouri Public Service Commission
Regulatory Proceedings [Line Items]
Public Utilities, Recovery Mechanism Percent for Fuel Cost						0.95
Public Utilities, Recovery Mechanism's Sharing Percentage for Fuel Cost						0.05
La Cygne Station | Evergy Kansas South Inc
Regulatory Proceedings [Line Items]
VIE ownership percentage						50.00%
Transmission delivery charge | Evergy Kansas Central | Kansas Corporation Commission
Regulatory Proceedings [Line Items]
Annual revenue increase (decrease) approved			$ 20.4
Transmission delivery charge | Evergy Metro | Kansas Corporation Commission
Regulatory Proceedings [Line Items]
Annual revenue increase (decrease) approved		$ 7.9
2018 Rate Case Proceedings | Evergy Kansas Central | Kansas Corporation Commission
Regulatory Proceedings [Line Items]
Refund percent on earnings over approved return on equity						0.50
Approved return on equity, percentage						9.30%
Estimated refund on earnings over approved return on equity	0.0					$ 0.0
2018 Rate Case Proceedings | Evergy Metro | Kansas Corporation Commission
Regulatory Proceedings [Line Items]
Refund percent on earnings over approved return on equity						0.50
Approved return on equity, percentage						9.30%
Estimated refund on earnings over approved return on equity	16.7					$ 16.7
2022 Rate case proceedings
Regulatory Proceedings [Line Items]
Deferral of revenues to regulatory liability for refund to customers for return on investment of retired Sibley Station						68.0
Asset Impairment Charges						26.7
Other regulatory disallowances, EMW meters						2.7
Deferral of revenues to regulatory liability for refund to customers for return on investment of retired Sibley Station						(68.0)
Other regulatory disallowances	5.5
2022 Rate case proceedings | Sibley AAO
Regulatory Proceedings [Line Items]
Regulatory liabilities	108.0					108.0
2022 Rate case proceedings | Retired generation facility, approved
Regulatory Proceedings [Line Items]
Regulatory assets	146.3					146.3
2022 Rate case proceedings | Evergy Metro
Regulatory Proceedings [Line Items]
Annual revenue increase (decrease) approved	25.0
Return on equity, requested				10.00%
Annual revenue increase (decrease), requested, not including rebasing fuel, purchased power expense and/or property tax expense				$ 43.9
Rate-making equity ratio, requested				51.19%
Annual revenue increase (decrease) related to rebasing, property tax and credit loss expense, storm reserve and return on unrecovered investment				$ 3.8
Other regulatory disallowances	5.5
2022 Rate case proceedings | Evergy Missouri West
Regulatory Proceedings [Line Items]
Annual revenue increase (decrease) approved	30.1
Return on equity, requested				10.00%
Annual revenue increase (decrease), requested, not including rebasing fuel, purchased power expense and/or property tax expense				$ 27.7
Rate-making equity ratio, requested				51.81%
Annual revenue increase (decrease) related to rebasing, property tax and credit loss expense, storm reserve and return on unrecovered investment				$ 32.1
Recovery of Sibley Station, approved	182.3
Recovery of Sibley Unit 3	173.6
Evergy Missouri West Other Proceedings
Regulatory Proceedings [Line Items]
Deferral of revenues to regulatory liability for refund to customers for return on investment of retired Sibley Station						68.0
Deferral of revenues to regulatory liability for refund to customers for return on investment of retired Sibley Station						(68.0)
Evergy Missouri West Other Proceedings | Sibley AAO
Regulatory Proceedings [Line Items]
Regulatory liabilities	29.3					29.3
FERC 2023 TFR Proceeding | TFR Refund
Regulatory Proceedings [Line Items]
Regulatory liabilities	32.8					32.8
FERC 2023 TFR Proceeding | Evergy Kansas Central | Federal Energy Regulatory Commission
Regulatory Proceedings [Line Items]
Annual transmissions revenue estimated amount of increase (decrease) over prior year						38.7
FERC 2023 TFR Proceeding | Evergy Metro | Federal Energy Regulatory Commission
Regulatory Proceedings [Line Items]
Annual transmissions revenue estimated amount of increase (decrease) over prior year						8.6
FERC 2022 TFR Proceeding | Evergy Kansas Central | Federal Energy Regulatory Commission
Regulatory Proceedings [Line Items]
Annual transmissions revenue estimated amount of increase (decrease) over prior year						33.2
FERC 2022 TFR Proceeding | Evergy Metro | Federal Energy Regulatory Commission
Regulatory Proceedings [Line Items]
Annual transmissions revenue estimated amount of increase (decrease) over prior year						18.1
FERC 2021 TFR Proceeding | Evergy Kansas Central | Federal Energy Regulatory Commission
Regulatory Proceedings [Line Items]
Annual transmissions revenue estimated amount of increase (decrease) over prior year						32.4
FERC 2021 TFR Proceeding | Evergy Metro | Federal Energy Regulatory Commission
Regulatory Proceedings [Line Items]
Annual transmissions revenue estimated amount of increase (decrease) over prior year						(3.9)
2021 KCC Winter Weather AAO | Evergy Kansas Central
Regulatory Proceedings [Line Items]
Carrying charges application rate			1.00%
2021 KCC Winter Weather AAO | Evergy Kansas Central | February 2021 winter weather event
Regulatory Proceedings [Line Items]
Regulatory assets	120.0					120.0
2021 KCC Winter Weather AAO | Evergy Metro
Regulatory Proceedings [Line Items]
Public Utilities, Requested Refund Increase (Decrease), Amount			$ (5.0)
Carrying charges application rate			1.00%
2021 KCC Winter Weather AAO | Evergy Metro | February 2021 winter weather event
Regulatory Proceedings [Line Items]
Regulatory liabilities	40.0					40.0
2021 MPSC Winter Weather | Evergy Metro
Regulatory Proceedings [Line Items]
Public Utilities, Requested Refund Increase (Decrease), Amount					$ (5.0)
2021 MPSC Winter Weather | Evergy Metro | February 2021 winter weather event
Regulatory Proceedings [Line Items]
Regulatory liabilities	25.0					25.0
2021 MPSC Winter Weather | Evergy Missouri West
Regulatory Proceedings [Line Items]
Public Utilities Requested Increase of Recovery					$ 15.0
2021 MPSC Winter Weather | Evergy Missouri West | February 2021 winter weather event
Regulatory Proceedings [Line Items]
Regulatory assets	280.0					$ 280.0
2021 MPSC Winter Weather Qualified Extraordinary Costs Securitization
Regulatory Proceedings [Line Items]
Regulatory Asset, Amortization Period						15 years
2021 MPSC Winter Weather Qualified Extraordinary Costs Securitization | Maximum
Regulatory Proceedings [Line Items]
Regulatory Asset, Amortization Period						17 years
2021 MPSC Winter Weather Qualified Extraordinary Costs Securitization | Evergy Missouri West | 2021 Winter Weather Qualified Extraordinary Costs Securitization
Regulatory Proceedings [Line Items]
Regulatory assets	309.0					$ 309.0	$ 281.6
2021 MPSC Winter Weather Qualified Extraordinary Costs Securitization | Evergy Missouri West | 2021 Winter Weather Qualified Carrying Costs Securitization
Regulatory Proceedings [Line Items]
Increase in regulatory asset	$ 15.0					$ 15.0