Consolidated Statements of Comprehensive Income - USD ($) shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Income Statement [Abstract]
OPERATING REVENUES	$ 1,669.3	$ 1,909.1	$ 4,320.3	$ 4,579.5
OPERATING EXPENSES:
Fuel and purchased power	478.4	643.0	1,177.4	1,366.3
SPP network transmission costs	75.4	81.6	232.0	241.8
Operating and maintenance	253.2	266.2	697.1	801.2
Depreciation and amortization	273.3	233.2	806.1	694.3
Taxes other than income tax	103.1	100.7	305.9	302.9
Sibley Unit 3 impairment loss	0.0	6.0	0.0	6.0
Total Operating Expenses	1,183.4	1,330.7	3,218.5	3,412.5
INCOME FROM OPERATIONS	485.9	578.4	1,101.8	1,167.0
OTHER INCOME (EXPENSE):
Investment earnings	6.2	13.1	22.0	2.6
Other income	19.3	6.2	34.1	20.3
Other expense	(12.8)	(16.7)	(55.1)	(64.5)
Total Other Income (Expense), Net	12.7	2.6	1.0	(41.6)
Interest expense	136.8	102.3	393.6	293.4
INCOME BEFORE INCOME TAXES	361.8	478.7	709.2	832.0
Income tax expense	8.8	49.5	32.0	83.1
Equity in earnings of equity method investees, net of income taxes	1.6	2.0	5.3	5.5
NET INCOME	354.6	431.2	682.5	754.4
Less: Net income attributable to noncontrolling interests	3.0	3.0	9.2	9.2
Net income attributable to Evergy, Inc.	$ 351.6	$ 428.2	$ 673.3	$ 745.2
BASIC AND DILUTED EARNINGS PER AVERAGE COMMON SHARE OUTSTANDING ATTRIBUTABLE TO EVERGY, INC. (see Note 1)
Basic earnings per common share (in dollars per share)	$ 1.53	$ 1.86	$ 2.93	$ 3.24
Diluted earnings per common share (in dollars per share)	$ 1.53	$ 1.86	$ 2.92	$ 3.23
Weighted Average Number of Shares Outstanding Reconciliation [Abstract]
Basic (in shares)	230.1	229.9	230.0	229.9
Diluted (in shares)	230.5	230.6	230.5	230.5
COMPREHENSIVE INCOME
NET INCOME	$ 354.6	$ 431.2	$ 682.5	$ 754.4
Derivative hedging activity
Reclassification to expenses, net of tax	1.5	1.4	4.1	4.1
Derivative hedging activity, net of tax	1.5	1.4	4.1	4.1
Defined benefit pension plans
Amortization of net losses included in net periodic benefit costs, net of tax	(0.1)	0.0	(0.1)	0.1
Change in unrecognized pension expense, net of tax	(0.1)	0.0	(0.1)	0.1
Total other comprehensive income	1.4	1.4	4.0	4.2
COMPREHENSIVE INCOME	356.0	432.6	686.5	758.6
Less:  Comprehensive income attributable to noncontrolling interest	3.0	3.0	9.2	9.2
Comprehensive Income, Net of Tax, Attributable to Parent, Total	$ 353.0	$ 429.6	$ 677.3	$ 749.4