RECEIVABLES - Pledged as Collateral (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable pledged as collateral	$ 425.0	$ 342.0
Evergy Kansas Central
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable pledged as collateral	215.0	166.0
Evergy Metro
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable pledged as collateral	$ 160.0	$ 126.0