ORGANIZATION AND BASIS OF PRESENTATION - Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023
Cash paid for (received from):
Interest, net of amount capitalized	$ 361.6	$ 370.3
Income taxes, net of refunds	18.1	19.0
Right-of-use assets obtained in exchange for new operating lease liabilities	4.1	12.1
Right-of-use assets obtained in exchange for new finance lease liabilities	12.4	3.7
Non-cash investing transactions:
Property, plant and equipment additions	178.7	171.4
Evergy Kansas Central
Cash paid for (received from):
Interest, net of amount capitalized	160.6	149.4
Income taxes, net of refunds	8.3	53.0
Right-of-use assets obtained in exchange for new operating lease liabilities	2.4	6.4
Right-of-use assets obtained in exchange for new finance lease liabilities	7.9	3.7
Non-cash investing transactions:
Property, plant and equipment additions	116.6	85.1
Evergy Metro
Cash paid for (received from):
Interest, net of amount capitalized	90.0	82.2
Income taxes, net of refunds	21.3	(0.4)
Right-of-use assets obtained in exchange for new operating lease liabilities	1.7	5.1
Right-of-use assets obtained in exchange for new finance lease liabilities	3.0	0.0
Non-cash investing transactions:
Property, plant and equipment additions	$ 47.7	$ 65.4