RECEIVABLES - Allowance for Credit Loses (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Mar. 31, 2023
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance January 1	$ 24.2	$ 31.4
Credit loss expense (income)	(1.1)	(3.3)
Write-offs	(7.9)	(8.3)
Recoveries of prior write-offs	3.3	3.1
Ending balance March 31	18.5	22.9
Evergy Kansas Central
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance January 1	11.6	16.9
Credit loss expense (income)	(0.4)	(1.8)
Write-offs	(3.6)	(4.3)
Recoveries of prior write-offs	1.4	1.3
Ending balance March 31	9.0	12.1
Evergy Metro
Accounts, Notes, Loans and Financing Receivable [Line Items]
Beginning balance January 1	7.9	9.3
Credit loss expense (income)	0.0	(0.8)
Write-offs	(2.8)	(2.7)
Recoveries of prior write-offs	1.3	1.2
Ending balance March 31	$ 6.4	$ 7.0