Consolidated Statements of Comprehensive Income - USD ($) shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Income Statement [Abstract]
OPERATING REVENUES	$ 1,116.7	$ 1,216.9
OPERATING EXPENSES:
Fuel and purchased power	258.2	330.0
SPP network transmission costs	62.0	63.5
Operating and maintenance	288.2	306.9
Depreciation and amortization	218.5	213.6
Taxes other than income tax	92.3	93.3
Total Operating Expenses	919.2	1,007.3
INCOME FROM OPERATIONS	197.5	209.6
OTHER INCOME (EXPENSE):
Investment earnings (loss)	(0.8)	3.2
Other income	2.3	8.2
Other expense	(22.7)	(19.4)
Total Other Expense, Net	(21.2)	(8.0)
Interest expense	96.2	91.1
INCOME BEFORE INCOME TAXES	80.1	110.5
Income tax expense	10.1	9.3
Equity in earnings of equity method investees, net of income taxes	2.2	2.2
NET INCOME	72.2	103.4
Less: Net income attributable to noncontrolling interests	2.8	3.9
Net income attributable to Evergy, Inc.	$ 69.4	$ 99.5
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)	$ 0.31	$ 0.39
Diluted earnings per common share (in dollars per share)	$ 0.31	$ 0.39
AVERAGE COMMON SHARES OUTSTANDING
Basic (in shares)	227.1	252.8
Diluted (in shares)	227.5	253.0
COMPREHENSIVE INCOME
Net income	$ 72.2	$ 103.4
Derivative hedging activity
Loss on derivative hedging instruments	0.0	(13.8)
Income tax benefit	0.0	3.6
Net loss on derivative hedging instruments	0.0	(10.2)
Reclassification to expenses, net of tax	1.3	0.0
Derivative hedging activity, net of tax	1.3	(10.2)
Total other comprehensive income (loss)	1.3	(10.2)
Comprehensive income	73.5	93.2
Less: comprehensive income attributable to noncontrolling interest	2.8	3.9
COMPREHENSIVE INCOME (LOSS)	$ 70.7	$ 89.3