FAIR VALUE MEASUREMENTS - NAV (Details) $ in Millions	6 Months Ended
Jun. 30, 2026 USD ($) fund	Dec. 31, 2025 USD ($)
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Unfunded Commitments	$ 1.3	$ 1.3
Evergy Kansas Central \| Alternative investments fund
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Unfunded Commitments	0.0	0.0
Evergy Kansas Central \| Real estate securities fund
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Unfunded Commitments	0.0	0.0
Domestic \| Evergy Kansas Central \| Equity securities
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Unfunded Commitments	$ 1.3	1.3
NAV, number of funds \| fund	4
Fair Value, Measurements, Recurring
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total nuclear decommissioning trust	$ 1,080.2	1,016.8
Total rabbi trust	29.8	31.2
Total Assets	1,205.4	1,113.5
Fair Value, Measurements, Recurring \| Evergy Kansas Central
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total nuclear decommissioning trust	481.5	466.0
Total rabbi trust	22.5	23.5
Total Assets	550.9	529.4
Fair Value, Measurements, Recurring \| Evergy Kansas Central \| Alternative investments fund
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total nuclear decommissioning trust	47.7	49.6
Fair Value, Measurements, Recurring \| Evergy Kansas Central \| Real estate securities fund
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total nuclear decommissioning trust	17.2	16.8
Fair Value, Measurements, Recurring \| Evergy Kansas Central \| Core bond fund
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total nuclear decommissioning trust	71.9	71.5
Fair Value, Measurements, Recurring \| Evergy Kansas Central \| Combination debt/equity/other fund
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total nuclear decommissioning trust	23.5	23.8
Total rabbi trust	1.7	1.8
Fair Value, Measurements, Recurring \| Other Evergy
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total rabbi trust	7.3	7.7
Total Assets	10.6	8.5
Fair Value, Measurements, Recurring \| Other Evergy \| Core bond fund
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total rabbi trust	7.3	7.7
Fair Value, Measurements, Recurring \| Domestic \| Evergy Kansas Central \| Equity securities
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total nuclear decommissioning trust	172.6	159.8
NAV \| Fair Value, Measurements, Recurring
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total nuclear decommissioning trust	73.2	74.7
Total rabbi trust	0.0	0.0
Total Assets	73.2	74.7
NAV \| Fair Value, Measurements, Recurring \| Evergy Kansas Central
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total nuclear decommissioning trust	73.2	74.7
Total rabbi trust	0.0	0.0
Total Assets	73.2	74.7
NAV \| Fair Value, Measurements, Recurring \| Evergy Kansas Central \| Alternative investments fund
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total nuclear decommissioning trust	$ 47.7	49.6
Length of Settlement	65 days
NAV \| Fair Value, Measurements, Recurring \| Evergy Kansas Central \| Real estate securities fund
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total nuclear decommissioning trust	$ 17.2	16.8
Length of Settlement	65 days
NAV \| Fair Value, Measurements, Recurring \| Evergy Kansas Central \| Core bond fund
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total nuclear decommissioning trust	$ 0.0	0.0
NAV \| Fair Value, Measurements, Recurring \| Evergy Kansas Central \| Combination debt/equity/other fund
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total nuclear decommissioning trust	0.0	0.0
Total rabbi trust	0.0	0.0
NAV \| Fair Value, Measurements, Recurring \| Other Evergy
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total rabbi trust	0.0	0.0
Total Assets	0.0	0.0
NAV \| Fair Value, Measurements, Recurring \| Other Evergy \| Core bond fund
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total rabbi trust	0.0	0.0
NAV \| Fair Value, Measurements, Recurring \| Domestic \| Evergy Kansas Central \| Equity securities
Fair Value, Investments, Entities that Calculate Net Asset Value Per Share [Line Items]
Total nuclear decommissioning trust	$ 8.3	$ 8.3

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