Derivative Instruments - Notional Amounts (Details) - Not Designated as Hedging Instrument [Member] MWh in Millions, MMBTU in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2024 MWh MMBTU	Dec. 31, 2023 MWh MMBTU
Natural gas commodity contract
Price Risk Derivatives [Abstract]
Derivative, Nonmonetary Notional Amount, Energy Measure | MMBTU	550.1	559.9
Power commodity contract
Price Risk Derivatives [Abstract]
Derivative, Nonmonetary Notional Amount, Energy Measure	28.3	52.9
Evergy Kansas Central | Natural gas commodity contract
Price Risk Derivatives [Abstract]
Derivative, Nonmonetary Notional Amount, Energy Measure | MMBTU	550.1	558.7
Evergy Kansas Central | Power commodity contract
Price Risk Derivatives [Abstract]
Derivative, Nonmonetary Notional Amount, Energy Measure	18.8	32.1
Evergy Metro | Power commodity contract
Price Risk Derivatives [Abstract]
Derivative, Nonmonetary Notional Amount, Energy Measure	7.1	15.1