FAIR VALUE MEASUREMENTS - Recurring (Details) - Fair Value, Measurements, Recurring - USD ($) $ in Millions | Mar. 31, 2022 | Dec. 31, 2021 |
Assets | | |
Equity securities | | $ 31.4 |
Total nuclear decommissioning trust | $ 733.2 | 768.7 |
Total rabbi trust | 40.7 | 44.2 |
Total self-insured health plan trust | 12.6 | 12.5 |
Total Assets | 786.5 | 856.8 |
Level 1 | | |
Assets | | |
Equity securities | | 0 |
Total nuclear decommissioning trust | 624.3 | 658.7 |
Total rabbi trust | 40.7 | 44.2 |
Total self-insured health plan trust | 6.9 | 6.5 |
Total Assets | 671.9 | 709.4 |
Level 2 | | |
Assets | | |
Equity securities | | 31.4 |
Total nuclear decommissioning trust | 46.2 | 48.2 |
Total rabbi trust | 0 | 0 |
Total self-insured health plan trust | 5.7 | 6 |
Total Assets | 51.9 | 85.6 |
Level 3 | | |
Assets | | |
Equity securities | | 0 |
Total nuclear decommissioning trust | 0 | 0 |
Total rabbi trust | 0 | 0 |
Total self-insured health plan trust | 0 | 0 |
Total Assets | 0 | 0 |
NAV | | |
Assets | | |
Equity securities | | 0 |
Total nuclear decommissioning trust | 62.7 | 61.8 |
Total rabbi trust | 0 | 0 |
Total self-insured health plan trust | 0 | 0 |
Total Assets | 62.7 | 61.8 |
Evergy Kansas Central | | |
Assets | | |
Total nuclear decommissioning trust | 354.1 | 368.4 |
Total rabbi trust | 29 | 31.7 |
Total Assets | 383.1 | 400.1 |
Evergy Kansas Central | Core bond fund | | |
Assets | | |
Total nuclear decommissioning trust | 55.1 | 58.1 |
Evergy Kansas Central | High-yield bond fund | | |
Assets | | |
Total nuclear decommissioning trust | 28.8 | 29.6 |
Evergy Kansas Central | Emerging markets bond fund | | |
Assets | | |
Total nuclear decommissioning trust | 16.8 | 18 |
Evergy Kansas Central | Combination debt/equity/other fund | | |
Assets | | |
Total rabbi trust | 2.2 | 2.4 |
Evergy Kansas Central | Alternative investments fund | | |
Assets | | |
Total nuclear decommissioning trust | 32.6 | 32.7 |
Evergy Kansas Central | Real estate securities fund | | |
Assets | | |
Total nuclear decommissioning trust | 16.5 | 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 | 8.6 | 9.5 |
Evergy Kansas Central | Fixed income funds | | |
Assets | | |
Total rabbi trust | 18.1 | 19.6 |
Evergy Kansas Central | Level 1 | | |
Assets | | |
Total nuclear decommissioning trust | 291.4 | 306.6 |
Total rabbi trust | 29 | 31.7 |
Total Assets | 320.4 | 338.3 |
Evergy Kansas Central | Level 1 | Core bond fund | | |
Assets | | |
Total nuclear decommissioning trust | 55.1 | 58.1 |
Evergy Kansas Central | Level 1 | High-yield bond fund | | |
Assets | | |
Total nuclear decommissioning trust | 28.8 | 29.6 |
Evergy Kansas Central | Level 1 | Emerging markets bond fund | | |
Assets | | |
Total nuclear decommissioning trust | 16.8 | 18 |
Evergy Kansas Central | Level 1 | Combination debt/equity/other fund | | |
Assets | | |
Total rabbi trust | 2.2 | 2.4 |
Evergy Kansas Central | Level 1 | Alternative investments fund | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Evergy Kansas Central | Level 1 | Real estate securities fund | | |
Assets | | |
Total nuclear decommissioning trust | 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 | 8.6 | 9.5 |
Evergy Kansas Central | Level 1 | Fixed income funds | | |
Assets | | |
Total rabbi trust | 18.1 | 19.6 |
Evergy Kansas Central | Level 2 | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Total rabbi trust | 0 | 0 |
Total Assets | 0 | 0 |
Evergy Kansas Central | Level 2 | Core bond fund | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Evergy Kansas Central | Level 2 | High-yield bond fund | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Evergy Kansas Central | Level 2 | Emerging markets bond fund | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Evergy Kansas Central | Level 2 | Combination debt/equity/other fund | | |
Assets | | |
Total rabbi trust | 0 | 0 |
Evergy Kansas Central | Level 2 | Alternative investments fund | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Evergy Kansas Central | Level 2 | Real estate securities fund | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Evergy Kansas Central | Level 2 | Cash equivalents | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Total rabbi trust | 0 | 0 |
Evergy Kansas Central | Level 2 | Equity funds | | |
Assets | | |
Total rabbi trust | 0 | 0 |
Evergy Kansas Central | Level 2 | Fixed income funds | | |
Assets | | |
Total rabbi trust | 0 | 0 |
Evergy Kansas Central | Level 3 | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Total rabbi trust | 0 | 0 |
Total Assets | 0 | 0 |
Evergy Kansas Central | Level 3 | Core bond fund | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Evergy Kansas Central | Level 3 | High-yield bond fund | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Evergy Kansas Central | Level 3 | Emerging markets bond fund | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Evergy Kansas Central | Level 3 | Combination debt/equity/other fund | | |
Assets | | |
Total rabbi trust | 0 | 0 |
Evergy Kansas Central | Level 3 | Alternative investments fund | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Evergy Kansas Central | Level 3 | Real estate securities fund | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Evergy Kansas Central | Level 3 | Cash equivalents | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Total rabbi trust | 0 | 0 |
Evergy Kansas Central | Level 3 | Equity funds | | |
Assets | | |
Total rabbi trust | 0 | 0 |
Evergy Kansas Central | Level 3 | Fixed income funds | | |
Assets | | |
Total rabbi trust | 0 | 0 |
Evergy Kansas Central | NAV | | |
Assets | | |
Total nuclear decommissioning trust | 62.7 | 61.8 |
Total rabbi trust | 0 | 0 |
Total Assets | 62.7 | 61.8 |
Evergy Kansas Central | NAV | Core bond fund | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Evergy Kansas Central | NAV | High-yield bond fund | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Evergy Kansas Central | NAV | Emerging markets bond fund | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Evergy Kansas Central | NAV | Combination debt/equity/other fund | | |
Assets | | |
Total rabbi trust | 0 | 0 |
Evergy Kansas Central | NAV | Alternative investments fund | | |
Assets | | |
Total nuclear decommissioning trust | 32.6 | 32.7 |
Evergy Kansas Central | NAV | Real estate securities fund | | |
Assets | | |
Total nuclear decommissioning trust | 16.5 | 15.2 |
Evergy Kansas Central | NAV | Cash equivalents | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Total rabbi trust | 0 | 0 |
Evergy Kansas Central | NAV | Equity funds | | |
Assets | | |
Total rabbi trust | 0 | 0 |
Evergy Kansas Central | NAV | Fixed income funds | | |
Assets | | |
Total rabbi trust | 0 | 0 |
Evergy Kansas Central | Domestic | Equity securities | | |
Assets | | |
Total nuclear decommissioning trust | 133.8 | 140.4 |
Evergy Kansas Central | Domestic | Level 1 | Equity securities | | |
Assets | | |
Total nuclear decommissioning trust | 120.2 | 126.5 |
Evergy Kansas Central | Domestic | Level 2 | Equity securities | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Evergy Kansas Central | Domestic | Level 3 | Equity securities | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Evergy Kansas Central | Domestic | NAV | Equity securities | | |
Assets | | |
Total nuclear decommissioning trust | 13.6 | 13.9 |
Evergy Kansas Central | International | Equity securities | | |
Assets | | |
Total nuclear decommissioning trust | 69.9 | 74 |
Evergy Kansas Central | International | Level 1 | Equity securities | | |
Assets | | |
Total nuclear decommissioning trust | 69.9 | 74 |
Evergy Kansas Central | International | Level 2 | Equity securities | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Evergy Kansas Central | International | Level 3 | Equity securities | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Evergy Kansas Central | International | NAV | Equity securities | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Evergy Metro | | |
Assets | | |
Total nuclear decommissioning trust | 379.1 | 400.3 |
Total self-insured health plan trust | 12.6 | 12.5 |
Total Assets | 391.7 | 412.8 |
Evergy Metro | Equity securities | | |
Assets | | |
Total nuclear decommissioning trust | 283.4 | 299.2 |
Total self-insured health plan trust | 1.9 | 2 |
Evergy Metro | Cash equivalents | | |
Assets | | |
Total nuclear decommissioning trust | 3.4 | 6.8 |
Evergy Metro | U.S. Treasury | | |
Assets | | |
Total nuclear decommissioning trust | 46.1 | 46.1 |
Evergy Metro | U.S. Agency | | |
Assets | | |
Total nuclear decommissioning trust | 0.4 | 0.4 |
Evergy Metro | State and local obligations | | |
Assets | | |
Total nuclear decommissioning trust | 3.9 | 4 |
Evergy Metro | Corporate bonds | | |
Assets | | |
Total nuclear decommissioning trust | 41.8 | 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 | 8.2 | 8.7 |
Evergy Metro | Cash and cash equivalents | | |
Assets | | |
Total self-insured health plan trust | 2.5 | 1.8 |
Evergy Metro | Level 1 | | |
Assets | | |
Total nuclear decommissioning trust | 332.9 | 352.1 |
Total self-insured health plan trust | 6.9 | 6.5 |
Total Assets | 339.8 | 358.6 |
Evergy Metro | Level 1 | Equity securities | | |
Assets | | |
Total nuclear decommissioning trust | 283.4 | 299.2 |
Total self-insured health plan trust | 1.9 | 2 |
Evergy Metro | Level 1 | Cash equivalents | | |
Assets | | |
Total nuclear decommissioning trust | 3.4 | 6.8 |
Evergy Metro | Level 1 | U.S. Treasury | | |
Assets | | |
Total nuclear decommissioning trust | 46.1 | 46.1 |
Evergy Metro | Level 1 | U.S. Agency | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Evergy Metro | Level 1 | State and local obligations | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Evergy Metro | Level 1 | Corporate bonds | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Evergy Metro | Level 1 | Foreign governments | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Evergy Metro | Level 1 | Debt securities | | |
Assets | | |
Total self-insured health plan trust | 2.5 | 2.7 |
Evergy Metro | Level 1 | Cash and cash equivalents | | |
Assets | | |
Total self-insured health plan trust | 2.5 | 1.8 |
Evergy Metro | Level 2 | | |
Assets | | |
Total nuclear decommissioning trust | 46.2 | 48.2 |
Total self-insured health plan trust | 5.7 | 6 |
Total Assets | 51.9 | 54.2 |
Evergy Metro | Level 2 | Equity securities | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Total self-insured health plan trust | 0 | 0 |
Evergy Metro | Level 2 | Cash equivalents | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Evergy Metro | Level 2 | U.S. Treasury | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Evergy Metro | Level 2 | U.S. Agency | | |
Assets | | |
Total nuclear decommissioning trust | 0.4 | 0.4 |
Evergy Metro | Level 2 | State and local obligations | | |
Assets | | |
Total nuclear decommissioning trust | 3.9 | 4 |
Evergy Metro | Level 2 | Corporate bonds | | |
Assets | | |
Total nuclear decommissioning trust | 41.8 | 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 |
Evergy Metro | Level 2 | Cash and cash equivalents | | |
Assets | | |
Total self-insured health plan trust | 0 | 0 |
Evergy Metro | Level 3 | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Total self-insured health plan trust | 0 | 0 |
Total Assets | 0 | 0 |
Evergy Metro | Level 3 | Equity securities | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Total self-insured health plan trust | 0 | 0 |
Evergy Metro | Level 3 | Cash equivalents | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Evergy Metro | Level 3 | U.S. Treasury | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Evergy Metro | Level 3 | U.S. Agency | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Evergy Metro | Level 3 | State and local obligations | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Evergy Metro | Level 3 | Corporate bonds | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Evergy Metro | Level 3 | Foreign governments | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Evergy Metro | Level 3 | Debt securities | | |
Assets | | |
Total self-insured health plan trust | 0 | 0 |
Evergy Metro | Level 3 | Cash and cash equivalents | | |
Assets | | |
Total self-insured health plan trust | 0 | 0 |
Evergy Metro | NAV | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Total self-insured health plan trust | 0 | 0 |
Total Assets | 0 | 0 |
Evergy Metro | NAV | Equity securities | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Total self-insured health plan trust | 0 | 0 |
Evergy Metro | NAV | Cash equivalents | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Evergy Metro | NAV | U.S. Treasury | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Evergy Metro | NAV | U.S. Agency | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Evergy Metro | NAV | State and local obligations | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Evergy Metro | NAV | Corporate bonds | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Evergy Metro | NAV | Foreign governments | | |
Assets | | |
Total nuclear decommissioning trust | 0 | 0 |
Evergy Metro | NAV | Debt securities | | |
Assets | | |
Total self-insured health plan trust | 0 | 0 |
Evergy Metro | NAV | Cash and cash equivalents | | |
Assets | | |
Total self-insured health plan trust | 0 | 0 |
Other Evergy | | |
Assets | | |
Equity securities | | 31.4 |
Total rabbi trust | | 12.5 |
Total Assets | 11.7 | 43.9 |
Other Evergy | Equity securities | | |
Assets | | |
Equity securities | | 31.4 |
Other Evergy | Core bond fund | | |
Assets | | |
Total rabbi trust | 11.7 | 12.5 |
Other Evergy | Level 1 | | |
Assets | | |
Equity securities | | 0 |
Total rabbi trust | | 12.5 |
Total Assets | 11.7 | 12.5 |
Other Evergy | Level 1 | Equity securities | | |
Assets | | |
Equity securities | | 0 |
Other Evergy | Level 1 | Core bond fund | | |
Assets | | |
Total rabbi trust | 11.7 | 12.5 |
Other Evergy | Level 2 | | |
Assets | | |
Equity securities | | 31.4 |
Total rabbi trust | | 0 |
Total Assets | 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 |
Other Evergy | Level 3 | | |
Assets | | |
Equity securities | | 0 |
Total rabbi trust | | 0 |
Total Assets | 0 | 0 |
Other Evergy | Level 3 | Equity securities | | |
Assets | | |
Equity securities | | 0 |
Other Evergy | Level 3 | Core bond fund | | |
Assets | | |
Total rabbi trust | 0 | 0 |
Other Evergy | NAV | | |
Assets | | |
Equity securities | | 0 |
Total rabbi trust | | 0 |
Total Assets | 0 | 0 |
Other Evergy | NAV | Equity securities | | |
Assets | | |
Equity securities | | 0 |
Other Evergy | NAV | Core bond fund | | |
Assets | | |
Total rabbi trust | $ 0 | $ 0 |