RECEIVABLES - Other Receivables (Details) - USD ($) $ in Millions	Mar. 31, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
Other receivables, contracts with customers	$ 45.8	$ 42.0
Evergy Kansas Central
Accounts, Notes, Loans and Financing Receivable [Line Items]
Other receivables, contracts with customers	43.9	37.7
Evergy Metro
Accounts, Notes, Loans and Financing Receivable [Line Items]
Other receivables, contracts with customers	$ 1.3	$ 1.2