ORGANIZATION AND BASIS OF PRESENTATION - Fuel Inventory and Supplies (Details) - USD ($) $ in Millions |
Jun. 30, 2026 |
Dec. 31, 2025 |
|---|---|---|
| Inventory [Line Items] | ||
| Fuel inventory and supplies | $ 867.5 | $ 828.9 |
| Evergy Kansas Central | ||
| Inventory [Line Items] | ||
| Fuel inventory and supplies | 449.5 | 437.9 |
| Evergy Metro | ||
| Inventory [Line Items] | ||
| Fuel inventory and supplies | 292.4 | 279.9 |
| Supplies [Member] | ||
| Inventory [Line Items] | ||
| Fuel inventory and supplies | 626.8 | 610.3 |
| Supplies [Member] | Evergy Kansas Central | ||
| Inventory [Line Items] | ||
| Fuel inventory and supplies | 323.7 | 323.0 |
| Supplies [Member] | Evergy Metro | ||
| Inventory [Line Items] | ||
| Fuel inventory and supplies | 214.2 | 210.3 |
| Public Utilities, Inventory, Fuel [Member] | ||
| Inventory [Line Items] | ||
| Fuel inventory and supplies | 240.7 | 218.6 |
| Public Utilities, Inventory, Fuel [Member] | Evergy Kansas Central | ||
| Inventory [Line Items] | ||
| Fuel inventory and supplies | 125.8 | 114.9 |
| Public Utilities, Inventory, Fuel [Member] | Evergy Metro | ||
| Inventory [Line Items] | ||
| Fuel inventory and supplies | $ 78.2 | $ 69.6 |