FAIR VALUE MEASUREMENTS - Recurring (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Millions	Sep. 30, 2022	Dec. 31, 2021
Assets
Total nuclear decommissioning trust	$ 613.5	$ 768.7
Total rabbi trust	34.9	44.2
Total self-insured health plan trust	12.4	12.5
Equity securities		31.4
Total Assets	660.8	856.8
Level 1
Assets
Total nuclear decommissioning trust	508.8	658.7
Total rabbi trust	34.9	44.2
Total self-insured health plan trust	6.7	6.5
Equity securities		0.0
Total Assets	550.4	709.4
Level 2
Assets
Total nuclear decommissioning trust	40.9	48.2
Total rabbi trust	0.0	0.0
Total self-insured health plan trust	5.7	6.0
Equity securities		31.4
Total Assets	46.6	85.6
Level 3
Assets
Total nuclear decommissioning trust	0.0	0.0
Total rabbi trust	0.0	0.0
Total self-insured health plan trust	0.0	0.0
Equity securities		0.0
Total Assets	0.0	0.0
NAV
Assets
Total nuclear decommissioning trust	63.8	61.8
Total rabbi trust	0.0	0.0
Total self-insured health plan trust	0.0	0.0
Equity securities		0.0
Total Assets	63.8	61.8
Evergy Kansas Central
Assets
Total nuclear decommissioning trust	300.5	368.4
Total rabbi trust	24.2	31.7
Total Assets	324.7	400.1
Evergy Kansas Central | Core bond fund
Assets
Total nuclear decommissioning trust	50.2	58.1
Evergy Kansas Central | High-yield bond fund
Assets
Total nuclear decommissioning trust	24.7	29.6
Evergy Kansas Central | Emerging markets bond fund
Assets
Total nuclear decommissioning trust	14.7	18.0
Evergy Kansas Central | Combination debt/equity/other fund
Assets
Total rabbi trust	1.9	2.4
Evergy Kansas Central | Alternative investments fund
Assets
Total nuclear decommissioning trust	32.2	32.7
Evergy Kansas Central | Real estate securities fund
Assets
Total nuclear decommissioning trust	18.6	15.2
Evergy Kansas Central | Cash equivalents
Assets
Total nuclear decommissioning trust	0.6	0.4
Total rabbi trust	0.1	0.2
Evergy Kansas Central | Equity funds
Assets
Total rabbi trust	6.7	9.5
Evergy Kansas Central | Fixed income funds
Assets
Total rabbi trust	15.5	19.6
Evergy Kansas Central | Level 1
Assets
Total nuclear decommissioning trust	236.7	306.6
Total rabbi trust	24.2	31.7
Total Assets	260.9	338.3
Evergy Kansas Central | Level 1 | Core bond fund
Assets
Total nuclear decommissioning trust	50.2	58.1
Evergy Kansas Central | Level 1 | High-yield bond fund
Assets
Total nuclear decommissioning trust	24.7	29.6
Evergy Kansas Central | Level 1 | Emerging markets bond fund
Assets
Total nuclear decommissioning trust	14.7	18.0
Evergy Kansas Central | Level 1 | Combination debt/equity/other fund
Assets
Total rabbi trust	1.9	2.4
Evergy Kansas Central | Level 1 | Alternative investments fund
Assets
Total nuclear decommissioning trust	0.0	0.0
Evergy Kansas Central | Level 1 | Real estate securities fund
Assets
Total nuclear decommissioning trust	0.0	0.0
Evergy Kansas Central | Level 1 | Cash equivalents
Assets
Total nuclear decommissioning trust	0.6	0.4
Total rabbi trust	0.1	0.2
Evergy Kansas Central | Level 1 | Equity funds
Assets
Total rabbi trust	6.7	9.5
Evergy Kansas Central | Level 1 | Fixed income funds
Assets
Total rabbi trust	15.5	19.6
Evergy Kansas Central | Level 2
Assets
Total nuclear decommissioning trust	0.0	0.0
Total rabbi trust	0.0	0.0
Total Assets	0.0	0.0
Evergy Kansas Central | Level 2 | Core bond fund
Assets
Total nuclear decommissioning trust	0.0	0.0
Evergy Kansas Central | Level 2 | High-yield bond fund
Assets
Total nuclear decommissioning trust	0.0	0.0
Evergy Kansas Central | Level 2 | Emerging markets bond fund
Assets
Total nuclear decommissioning trust	0.0	0.0
Evergy Kansas Central | Level 2 | Combination debt/equity/other fund
Assets
Total rabbi trust	0.0	0.0
Evergy Kansas Central | Level 2 | Alternative investments fund
Assets
Total nuclear decommissioning trust	0.0	0.0
Evergy Kansas Central | Level 2 | Real estate securities fund
Assets
Total nuclear decommissioning trust	0.0	0.0
Evergy Kansas Central | Level 2 | Cash equivalents
Assets
Total nuclear decommissioning trust	0.0	0.0
Total rabbi trust	0.0	0.0
Evergy Kansas Central | Level 2 | Equity funds
Assets
Total rabbi trust	0.0	0.0
Evergy Kansas Central | Level 2 | Fixed income funds
Assets
Total rabbi trust	0.0	0.0
Evergy Kansas Central | Level 3
Assets
Total nuclear decommissioning trust	0.0	0.0
Total rabbi trust	0.0	0.0
Total Assets	0.0	0.0
Evergy Kansas Central | Level 3 | Core bond fund
Assets
Total nuclear decommissioning trust	0.0	0.0
Evergy Kansas Central | Level 3 | High-yield bond fund
Assets
Total nuclear decommissioning trust	0.0	0.0
Evergy Kansas Central | Level 3 | Emerging markets bond fund
Assets
Total nuclear decommissioning trust	0.0	0.0
Evergy Kansas Central | Level 3 | Combination debt/equity/other fund
Assets
Total rabbi trust	0.0	0.0
Evergy Kansas Central | Level 3 | Alternative investments fund
Assets
Total nuclear decommissioning trust	0.0	0.0
Evergy Kansas Central | Level 3 | Real estate securities fund
Assets
Total nuclear decommissioning trust	0.0	0.0
Evergy Kansas Central | Level 3 | Cash equivalents
Assets
Total nuclear decommissioning trust	0.0	0.0
Total rabbi trust	0.0	0.0
Evergy Kansas Central | Level 3 | Equity funds
Assets
Total rabbi trust	0.0	0.0
Evergy Kansas Central | Level 3 | Fixed income funds
Assets
Total rabbi trust	0.0	0.0
Evergy Kansas Central | NAV
Assets
Total nuclear decommissioning trust	63.8	61.8
Total rabbi trust	0.0	0.0
Total Assets	63.8	61.8
Evergy Kansas Central | NAV | Core bond fund
Assets
Total nuclear decommissioning trust	0.0	0.0
Evergy Kansas Central | NAV | High-yield bond fund
Assets
Total nuclear decommissioning trust	0.0	0.0
Evergy Kansas Central | NAV | Emerging markets bond fund
Assets
Total nuclear decommissioning trust	0.0	0.0
Evergy Kansas Central | NAV | Combination debt/equity/other fund
Assets
Total rabbi trust	0.0	0.0
Evergy Kansas Central | NAV | Alternative investments fund
Assets
Total nuclear decommissioning trust	32.2	32.7
Evergy Kansas Central | NAV | Real estate securities fund
Assets
Total nuclear decommissioning trust	18.6	15.2
Evergy Kansas Central | NAV | Cash equivalents
Assets
Total nuclear decommissioning trust	0.0	0.0
Total rabbi trust	0.0	0.0
Evergy Kansas Central | NAV | Equity funds
Assets
Total rabbi trust	0.0	0.0
Evergy Kansas Central | NAV | Fixed income funds
Assets
Total rabbi trust	0.0	0.0
Evergy Kansas Central | Domestic | Equity securities
Assets
Total nuclear decommissioning trust	106.0	140.4
Evergy Kansas Central | Domestic | Level 1 | Equity securities
Assets
Total nuclear decommissioning trust	93.0	126.5
Evergy Kansas Central | Domestic | Level 2 | Equity securities
Assets
Total nuclear decommissioning trust	0.0	0.0
Evergy Kansas Central | Domestic | Level 3 | Equity securities
Assets
Total nuclear decommissioning trust	0.0	0.0
Evergy Kansas Central | Domestic | NAV | Equity securities
Assets
Total nuclear decommissioning trust	13.0	13.9
Evergy Kansas Central | International | Equity securities
Assets
Total nuclear decommissioning trust	53.5	74.0
Evergy Kansas Central | International | Level 1 | Equity securities
Assets
Total nuclear decommissioning trust	53.5	74.0
Evergy Kansas Central | International | Level 2 | Equity securities
Assets
Total nuclear decommissioning trust	0.0	0.0
Evergy Kansas Central | International | Level 3 | Equity securities
Assets
Total nuclear decommissioning trust	0.0	0.0
Evergy Kansas Central | International | NAV | Equity securities
Assets
Total nuclear decommissioning trust	0.0	0.0
Evergy Metro
Assets
Total nuclear decommissioning trust	313.0	400.3
Total self-insured health plan trust	12.4	12.5
Total Assets	325.4	412.8
Evergy Metro | Equity securities
Assets
Total nuclear decommissioning trust	224.7	299.2
Total self-insured health plan trust	1.5	2.0
Evergy Metro | Cash equivalents
Assets
Total nuclear decommissioning trust	5.3	6.8
Evergy Metro | U.S. Treasury
Assets
Total nuclear decommissioning trust	42.1	46.1
Evergy Metro | U.S. Agency
Assets
Total nuclear decommissioning trust	0.3	0.4
Evergy Metro | State and local obligations
Assets
Total nuclear decommissioning trust	4.1	4.0
Evergy Metro | Corporate bonds
Assets
Total nuclear decommissioning trust	36.4	43.7
Evergy Metro | Foreign governments
Assets
Total nuclear decommissioning trust	0.1	0.1
Evergy Metro | Debt securities
Assets
Total self-insured health plan trust	7.7	8.7
Evergy Metro | Cash and cash equivalents
Assets
Total self-insured health plan trust	3.2	1.8
Evergy Metro | Level 1
Assets
Total nuclear decommissioning trust	272.1	352.1
Total self-insured health plan trust	6.7	6.5
Total Assets	278.8	358.6
Evergy Metro | Level 1 | Equity securities
Assets
Total nuclear decommissioning trust	224.7	299.2
Total self-insured health plan trust	1.5	2.0
Evergy Metro | Level 1 | Cash equivalents
Assets
Total nuclear decommissioning trust	5.3	6.8
Evergy Metro | Level 1 | U.S. Treasury
Assets
Total nuclear decommissioning trust	42.1	46.1
Evergy Metro | Level 1 | U.S. Agency
Assets
Total nuclear decommissioning trust	0.0	0.0
Evergy Metro | Level 1 | State and local obligations
Assets
Total nuclear decommissioning trust	0.0	0.0
Evergy Metro | Level 1 | Corporate bonds
Assets
Total nuclear decommissioning trust	0.0	0.0
Evergy Metro | Level 1 | Foreign governments
Assets
Total nuclear decommissioning trust	0.0	0.0
Evergy Metro | Level 1 | Debt securities
Assets
Total self-insured health plan trust	2.0	2.7
Evergy Metro | Level 1 | Cash and cash equivalents
Assets
Total self-insured health plan trust	3.2	1.8
Evergy Metro | Level 2
Assets
Total nuclear decommissioning trust	40.9	48.2
Total self-insured health plan trust	5.7	6.0
Total Assets	46.6	54.2
Evergy Metro | Level 2 | Equity securities
Assets
Total nuclear decommissioning trust	0.0	0.0
Total self-insured health plan trust	0.0	0.0
Evergy Metro | Level 2 | Cash equivalents
Assets
Total nuclear decommissioning trust	0.0	0.0
Evergy Metro | Level 2 | U.S. Treasury
Assets
Total nuclear decommissioning trust	0.0	0.0
Evergy Metro | Level 2 | U.S. Agency
Assets
Total nuclear decommissioning trust	0.3	0.4
Evergy Metro | Level 2 | State and local obligations
Assets
Total nuclear decommissioning trust	4.1	4.0
Evergy Metro | Level 2 | Corporate bonds
Assets
Total nuclear decommissioning trust	36.4	43.7
Evergy Metro | Level 2 | Foreign governments
Assets
Total nuclear decommissioning trust	0.1	0.1
Evergy Metro | Level 2 | Debt securities
Assets
Total self-insured health plan trust	5.7	6.0
Evergy Metro | Level 2 | Cash and cash equivalents
Assets
Total self-insured health plan trust	0.0	0.0
Evergy Metro | Level 3
Assets
Total nuclear decommissioning trust	0.0	0.0
Total self-insured health plan trust	0.0	0.0
Total Assets	0.0	0.0
Evergy Metro | Level 3 | Equity securities
Assets
Total nuclear decommissioning trust	0.0	0.0
Total self-insured health plan trust	0.0	0.0
Evergy Metro | Level 3 | Cash equivalents
Assets
Total nuclear decommissioning trust	0.0	0.0
Evergy Metro | Level 3 | U.S. Treasury
Assets
Total nuclear decommissioning trust	0.0	0.0
Evergy Metro | Level 3 | U.S. Agency
Assets
Total nuclear decommissioning trust	0.0	0.0
Evergy Metro | Level 3 | State and local obligations
Assets
Total nuclear decommissioning trust	0.0	0.0
Evergy Metro | Level 3 | Corporate bonds
Assets
Total nuclear decommissioning trust	0.0	0.0
Evergy Metro | Level 3 | Foreign governments
Assets
Total nuclear decommissioning trust	0.0	0.0
Evergy Metro | Level 3 | Debt securities
Assets
Total self-insured health plan trust	0.0	0.0
Evergy Metro | Level 3 | Cash and cash equivalents
Assets
Total self-insured health plan trust	0.0	0.0
Evergy Metro | NAV
Assets
Total nuclear decommissioning trust	0.0	0.0
Total self-insured health plan trust	0.0	0.0
Total Assets	0.0	0.0
Evergy Metro | NAV | Equity securities
Assets
Total nuclear decommissioning trust	0.0	0.0
Total self-insured health plan trust	0.0	0.0
Evergy Metro | NAV | Cash equivalents
Assets
Total nuclear decommissioning trust	0.0	0.0
Evergy Metro | NAV | U.S. Treasury
Assets
Total nuclear decommissioning trust	0.0	0.0
Evergy Metro | NAV | U.S. Agency
Assets
Total nuclear decommissioning trust	0.0	0.0
Evergy Metro | NAV | State and local obligations
Assets
Total nuclear decommissioning trust	0.0	0.0
Evergy Metro | NAV | Corporate bonds
Assets
Total nuclear decommissioning trust	0.0	0.0
Evergy Metro | NAV | Foreign governments
Assets
Total nuclear decommissioning trust	0.0	0.0
Evergy Metro | NAV | Debt securities
Assets
Total self-insured health plan trust	0.0	0.0
Evergy Metro | NAV | Cash and cash equivalents
Assets
Total self-insured health plan trust	0.0	0.0
Other Evergy
Assets
Total rabbi trust		12.5
Equity securities		31.4
Total Assets	10.7	43.9
Other Evergy | Equity securities
Assets
Equity securities		31.4
Other Evergy | Core bond fund
Assets
Total rabbi trust	10.5	12.5
Other Evergy | Cash and cash equivalents
Assets
Total rabbi trust	0.2
Other Evergy | Level 1
Assets
Total rabbi trust		12.5
Equity securities		0.0
Total Assets	10.7	12.5
Other Evergy | Level 1 | Equity securities
Assets
Equity securities		0.0
Other Evergy | Level 1 | Core bond fund
Assets
Total rabbi trust	10.5	12.5
Other Evergy | Level 1 | Cash and cash equivalents
Assets
Total rabbi trust	0.2
Other Evergy | Level 2
Assets
Total rabbi trust		0.0
Equity securities		31.4
Total Assets	0.0	31.4
Other Evergy | Level 2 | Equity securities
Assets
Equity securities		31.4
Other Evergy | Level 2 | Core bond fund
Assets
Total rabbi trust	0.0	0.0
Other Evergy | Level 2 | Cash and cash equivalents
Assets
Total rabbi trust	0.0
Other Evergy | Level 3
Assets
Total rabbi trust		0.0
Equity securities		0.0
Total Assets	0.0	0.0
Other Evergy | Level 3 | Equity securities
Assets
Equity securities		0.0
Other Evergy | Level 3 | Core bond fund
Assets
Total rabbi trust	0.0	0.0
Other Evergy | Level 3 | Cash and cash equivalents
Assets
Total rabbi trust	0.0
Other Evergy | NAV
Assets
Total rabbi trust		0.0
Equity securities		0.0
Total Assets	0.0	0.0
Other Evergy | NAV | Equity securities
Assets
Equity securities		0.0
Other Evergy | NAV | Core bond fund
Assets
Total rabbi trust	0.0	$ 0.0
Other Evergy | NAV | Cash and cash equivalents
Assets
Total rabbi trust	$ 0.0