ORGANIZATION AND BASIS OF PRESENTATION - Organization (Details) customer in Millions, $ in Millions	9 Months Ended
	Sep. 30, 2025 USD ($) subsidiary customer kilovolt_line segment mi MW	Dec. 31, 2024 USD ($)
Summary Of Accounting Policies [Line Items]
Owned generating capacity and renewable purchased power	15,800
Number of customers served \| customer	1.7
Number of segments \| segment	1
Public utilities PISA allowed depreciation expense recovery, percent	85.00%
Plant to be constructed 1
Summary Of Accounting Policies [Line Items]
ApproximateMWNameplateCapacity	705
Plant to be constructed 2
Summary Of Accounting Policies [Line Items]
ApproximateMWNameplateCapacity	705
Prairie Wind Transmission, LLC
Summary Of Accounting Policies [Line Items]
Transmission line length \| mi	108
Transmission line electrical potential \| kilovolt_line	345
Evergy Kansas Central \| Kansas Sky solar plant to be constructed
Summary Of Accounting Policies [Line Items]
ApproximateMWNameplateCapacity	159
Evergy Missouri West \| Simple cycle natural gas plant to be constructed
Summary Of Accounting Policies [Line Items]
ApproximateMWNameplateCapacity	440
Evergy Missouri West \| 2024 Sunflower Sky Purchase [Member]
Summary Of Accounting Policies [Line Items]
ApproximateMWNameplateCapacity	65
Evergy Missouri West \| 2024 Foxtrot Purchase [Member]
Summary Of Accounting Policies [Line Items]
ApproximateMWNameplateCapacity	100
Evergy Kansas South Inc \| Evergy Kansas Central
Summary Of Accounting Policies [Line Items]
Number of active wholly owned subsidiaries \| subsidiary	1
Transource Energy, LLC \| Evergy Transmission Company LLC
Summary Of Accounting Policies [Line Items]
Ownership percentage	13.50%
Transource Energy, LLC \| AEP Transmission Holding Company, LLC
Summary Of Accounting Policies [Line Items]
Ownership interest	86.50%
Prairie Wind Transmission, LLC \| Evergy Kansas Central
Summary Of Accounting Policies [Line Items]
Ownership percentage	50.00%
Early-Stage Clean Energy and Energy Solution Investments
Summary Of Accounting Policies [Line Items]
Unrealized Gain on Investments \| $	$ 29.0
Investment in Early Stage Clean Energy and Energy Solution Investments \| $	$ 95.7	$ 121.4

Evergy, Inc. 10-Q