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PENSION PLANS AND POST-RETIREMENT BENEFITS - Fair Values of Assets (Details) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 1,250.7	$ 1,409.2	$ 1,714.7
Post-Retirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	201.5	192.9	242.3
Evergy Kansas Central | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	620.6	668.5	835.7
Evergy Kansas Central | Pension Benefits | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	495.6	530.8
Evergy Kansas Central | Pension Benefits | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Kansas Central | Pension Benefits | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Kansas Central | Pension Benefits | Assets measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	125.0	137.7
Evergy Kansas Central | Pension Benefits | Domestic equities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	145.9	156.8
Evergy Kansas Central | Pension Benefits | Domestic equities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	124.0	129.2
Evergy Kansas Central | Pension Benefits | Domestic equities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Kansas Central | Pension Benefits | Domestic equities | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Kansas Central | Pension Benefits | Domestic equities | Assets measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	21.9	27.6
Evergy Kansas Central | Pension Benefits | International equities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	118.2	129.1
Evergy Kansas Central | Pension Benefits | International equities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	118.2	129.1
Evergy Kansas Central | Pension Benefits | International equities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Kansas Central | Pension Benefits | International equities | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Kansas Central | Pension Benefits | International equities | Assets measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Kansas Central | Pension Benefits | Bond funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	224.2	241.7
Evergy Kansas Central | Pension Benefits | Bond funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	224.2	241.7
Evergy Kansas Central | Pension Benefits | Bond funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Kansas Central | Pension Benefits | Bond funds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Kansas Central | Pension Benefits | Bond funds | Assets measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Kansas Central | Pension Benefits | Real estate investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	23.0	26.8
Evergy Kansas Central | Pension Benefits | Real estate investments | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Kansas Central | Pension Benefits | Real estate investments | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Kansas Central | Pension Benefits | Real estate investments | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Kansas Central | Pension Benefits | Real estate investments | Assets measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	23.0	26.8
Evergy Kansas Central | Pension Benefits | Combination debt/equity/other fund
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	29.2	30.8
Evergy Kansas Central | Pension Benefits | Combination debt/equity/other fund | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	29.2	30.8
Evergy Kansas Central | Pension Benefits | Combination debt/equity/other fund | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Kansas Central | Pension Benefits | Combination debt/equity/other fund | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Kansas Central | Pension Benefits | Combination debt/equity/other fund | Assets measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Kansas Central | Pension Benefits | Alternative investment funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	74.6	63.9
Evergy Kansas Central | Pension Benefits | Alternative investment funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Kansas Central | Pension Benefits | Alternative investment funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Kansas Central | Pension Benefits | Alternative investment funds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Kansas Central | Pension Benefits | Alternative investment funds | Assets measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	74.6	63.9
Evergy Kansas Central | Pension Benefits | Short-term investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5.5	19.4
Evergy Kansas Central | Pension Benefits | Short-term investments | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Kansas Central | Pension Benefits | Short-term investments | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Kansas Central | Pension Benefits | Short-term investments | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Kansas Central | Pension Benefits | Short-term investments | Assets measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5.5	19.4
Evergy Kansas Central | Post-Retirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	99.1	96.2	124.0
Evergy Kansas Central | Post-Retirement Benefits | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	98.1	95.2
Evergy Kansas Central | Post-Retirement Benefits | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Kansas Central | Post-Retirement Benefits | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Kansas Central | Post-Retirement Benefits | Assets measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1.0	1.0
Evergy Kansas Central | Post-Retirement Benefits | Domestic equities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	26.1	24.2
Evergy Kansas Central | Post-Retirement Benefits | Domestic equities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	26.1	24.2
Evergy Kansas Central | Post-Retirement Benefits | Domestic equities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Kansas Central | Post-Retirement Benefits | Domestic equities | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Kansas Central | Post-Retirement Benefits | Domestic equities | Assets measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Kansas Central | Post-Retirement Benefits | International equities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	17.9	17.5
Evergy Kansas Central | Post-Retirement Benefits | International equities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	17.9	17.5
Evergy Kansas Central | Post-Retirement Benefits | International equities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Kansas Central | Post-Retirement Benefits | International equities | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Kansas Central | Post-Retirement Benefits | International equities | Assets measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Kansas Central | Post-Retirement Benefits | Bond funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	49.6	48.7
Evergy Kansas Central | Post-Retirement Benefits | Bond funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	49.6	48.7
Evergy Kansas Central | Post-Retirement Benefits | Bond funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Kansas Central | Post-Retirement Benefits | Bond funds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Kansas Central | Post-Retirement Benefits | Bond funds | Assets measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Kansas Central | Post-Retirement Benefits | Combination debt/equity/other fund
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4.5	4.8
Evergy Kansas Central | Post-Retirement Benefits | Combination debt/equity/other fund | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4.5	4.8
Evergy Kansas Central | Post-Retirement Benefits | Combination debt/equity/other fund | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Kansas Central | Post-Retirement Benefits | Combination debt/equity/other fund | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Kansas Central | Post-Retirement Benefits | Combination debt/equity/other fund | Assets measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Kansas Central | Post-Retirement Benefits | Short-term investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1.0	1.0
Evergy Kansas Central | Post-Retirement Benefits | Short-term investments | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Kansas Central | Post-Retirement Benefits | Short-term investments | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Kansas Central | Post-Retirement Benefits | Short-term investments | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Kansas Central | Post-Retirement Benefits | Short-term investments | Assets measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1.0	1.0
Evergy Metro | Pension Benefits
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	630.1	740.7	879.0
Evergy Metro | Pension Benefits | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	457.2	549.0
Evergy Metro | Pension Benefits | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	33.1	34.4
Evergy Metro | Pension Benefits | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Pension Benefits | Assets measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	139.8	157.3
Evergy Metro | Pension Benefits | Domestic equities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	138.9	156.1
Evergy Metro | Pension Benefits | Domestic equities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	122.9	135.5
Evergy Metro | Pension Benefits | Domestic equities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Pension Benefits | Domestic equities | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Pension Benefits | Domestic equities | Assets measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	16.0	20.6
Evergy Metro | Pension Benefits | International equities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	120.0	136.7
Evergy Metro | Pension Benefits | International equities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	120.0	136.7
Evergy Metro | Pension Benefits | International equities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Pension Benefits | International equities | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Pension Benefits | International equities | Assets measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Pension Benefits | Bond funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	174.9	195.2
Evergy Metro | Pension Benefits | Bond funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	174.9	195.2
Evergy Metro | Pension Benefits | Bond funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Pension Benefits | Bond funds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Pension Benefits | Bond funds | Assets measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Pension Benefits | Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	21.1	23.7
Evergy Metro | Pension Benefits | Corporate bonds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Pension Benefits | Corporate bonds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	21.1	23.7
Evergy Metro | Pension Benefits | Corporate bonds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Pension Benefits | Corporate bonds | Assets measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Pension Benefits | U.S. Treasury and agency bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	10.1	14.0
Evergy Metro | Pension Benefits | U.S. Treasury and agency bonds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5.1	5.8
Evergy Metro | Pension Benefits | U.S. Treasury and agency bonds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5.0	8.2
Evergy Metro | Pension Benefits | U.S. Treasury and agency bonds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Pension Benefits | U.S. Treasury and agency bonds | Assets measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Pension Benefits | Mortgage and asset backed securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5.1	5.0
Evergy Metro | Pension Benefits | Mortgage and asset backed securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Pension Benefits | Mortgage and asset backed securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5.1	5.0
Evergy Metro | Pension Benefits | Mortgage and asset backed securities | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Pension Benefits | Mortgage and asset backed securities | Assets measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Pension Benefits | Real estate investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	49.0	59.0
Evergy Metro | Pension Benefits | Real estate investments | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Pension Benefits | Real estate investments | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Pension Benefits | Real estate investments | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Pension Benefits | Real estate investments | Assets measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	49.0	59.0
Evergy Metro | Pension Benefits | Combination debt/equity/other fund
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	28.4	31.2
Evergy Metro | Pension Benefits | Combination debt/equity/other fund | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	28.4	31.2
Evergy Metro | Pension Benefits | Combination debt/equity/other fund | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Pension Benefits | Combination debt/equity/other fund | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Pension Benefits | Combination debt/equity/other fund | Assets measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Pension Benefits | Alternative investment funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	70.8	63.1
Evergy Metro | Pension Benefits | Alternative investment funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Pension Benefits | Alternative investment funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Pension Benefits | Alternative investment funds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Pension Benefits | Alternative investment funds | Assets measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	70.8	63.1
Evergy Metro | Pension Benefits | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5.9	44.6
Evergy Metro | Pension Benefits | Cash and cash equivalents | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	5.9	44.6
Evergy Metro | Pension Benefits | Cash and cash equivalents | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Pension Benefits | Cash and cash equivalents | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Pension Benefits | Cash and cash equivalents | Assets measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Pension Benefits | Short-term investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4.0	14.6
Evergy Metro | Pension Benefits | Short-term investments | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Pension Benefits | Short-term investments | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Pension Benefits | Short-term investments | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Pension Benefits | Short-term investments | Assets measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	4.0	14.6
Evergy Metro | Pension Benefits | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1.9	(2.5)
Evergy Metro | Pension Benefits | Other | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Pension Benefits | Other | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1.9	(2.5)
Evergy Metro | Pension Benefits | Other | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Pension Benefits | Other | Assets measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Post-Retirement Benefits
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	102.4	96.7	$ 118.3
Evergy Metro | Post-Retirement Benefits | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	79.8	74.3
Evergy Metro | Post-Retirement Benefits | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	22.4	22.4
Evergy Metro | Post-Retirement Benefits | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Post-Retirement Benefits | Assets measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.2	0.0
Evergy Metro | Post-Retirement Benefits | Domestic equities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	21.8	18.7
Evergy Metro | Post-Retirement Benefits | Domestic equities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	21.8	18.7
Evergy Metro | Post-Retirement Benefits | Domestic equities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Post-Retirement Benefits | Domestic equities | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Post-Retirement Benefits | Domestic equities | Assets measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Post-Retirement Benefits | International equities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	12.1	11.6
Evergy Metro | Post-Retirement Benefits | International equities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	12.1	11.6
Evergy Metro | Post-Retirement Benefits | International equities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Post-Retirement Benefits | International equities | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Post-Retirement Benefits | International equities | Assets measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Post-Retirement Benefits | Bond funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	36.8	34.9
Evergy Metro | Post-Retirement Benefits | Bond funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	36.8	34.9
Evergy Metro | Post-Retirement Benefits | Bond funds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Post-Retirement Benefits | Bond funds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Post-Retirement Benefits | Bond funds | Assets measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Post-Retirement Benefits | Corporate bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	15.0	14.6
Evergy Metro | Post-Retirement Benefits | Corporate bonds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Post-Retirement Benefits | Corporate bonds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	15.0	14.6
Evergy Metro | Post-Retirement Benefits | Corporate bonds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Post-Retirement Benefits | Corporate bonds | Assets measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Post-Retirement Benefits | U.S. Treasury and agency bonds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	12.2	12.3
Evergy Metro | Post-Retirement Benefits | U.S. Treasury and agency bonds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6.1	6.0
Evergy Metro | Post-Retirement Benefits | U.S. Treasury and agency bonds | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6.1	6.3
Evergy Metro | Post-Retirement Benefits | U.S. Treasury and agency bonds | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Post-Retirement Benefits | U.S. Treasury and agency bonds | Assets measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Post-Retirement Benefits | Mortgage and asset backed securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1.0	1.3
Evergy Metro | Post-Retirement Benefits | Mortgage and asset backed securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Post-Retirement Benefits | Mortgage and asset backed securities | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1.0	1.3
Evergy Metro | Post-Retirement Benefits | Mortgage and asset backed securities | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Post-Retirement Benefits | Mortgage and asset backed securities | Assets measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Post-Retirement Benefits | Combination debt/equity/other fund
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3.0	2.9
Evergy Metro | Post-Retirement Benefits | Combination debt/equity/other fund | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	3.0	2.9
Evergy Metro | Post-Retirement Benefits | Combination debt/equity/other fund | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Post-Retirement Benefits | Combination debt/equity/other fund | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Post-Retirement Benefits | Combination debt/equity/other fund | Assets measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Post-Retirement Benefits | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.2
Evergy Metro | Post-Retirement Benefits | Cash and cash equivalents | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.2
Evergy Metro | Post-Retirement Benefits | Cash and cash equivalents | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.0
Evergy Metro | Post-Retirement Benefits | Cash and cash equivalents | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.0
Evergy Metro | Post-Retirement Benefits | Cash and cash equivalents | Assets measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets		0.0
Evergy Metro | Post-Retirement Benefits | Short-term investments
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.2
Evergy Metro | Post-Retirement Benefits | Short-term investments | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0
Evergy Metro | Post-Retirement Benefits | Short-term investments | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0
Evergy Metro | Post-Retirement Benefits | Short-term investments | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0
Evergy Metro | Post-Retirement Benefits | Short-term investments | Assets measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.2
Evergy Metro | Post-Retirement Benefits | Other
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.3	0.2
Evergy Metro | Post-Retirement Benefits | Other | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Post-Retirement Benefits | Other | Level 2
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.3	0.2
Evergy Metro | Post-Retirement Benefits | Other | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	0.0	0.0
Evergy Metro | Post-Retirement Benefits | Other | Assets measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 0.0	$ 0.0

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