Consolidated Statements of Changes in Equity - Evergy Metro, Inc - USD ($) $ in Millions	Total	Common Stock	Retained earnings	Evergy Metro	Evergy Metro Common Stock	Evergy Metro Retained earnings	Evergy Metro AOCI - Net gains (losses) on cash flow hedges
Beginning balance (in shares) at Dec. 31, 2020		226,836,670			1
Beginning balance at Dec. 31, 2020	$ 8,718.5	$ 7,080.0	$ 1,702.8	$ 2,759.2	$ 1,563.1	$ 1,191.5	$ 4.6
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	194.6		191.6	33.5		33.5
Dividends declared on common stock	(121.4)		(121.4)
Derivative hedging activity, net of tax	1.4			0.0
Ending balance (in shares) at Mar. 31, 2021		226,995,620			1
Ending balance at Mar. 31, 2021	8,794.4	$ 7,081.5	1,772.8	2,792.7	$ 1,563.1	1,225.0	4.6
Beginning balance (in shares) at Dec. 31, 2021		229,299,900			1
Beginning balance at Dec. 31, 2021	9,241.7	$ 7,205.5	2,082.9	3,021.2	$ 1,563.1	1,453.8	4.3
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	125.6		122.5	54.6		54.6
Dividends declared on common stock	(131.3)		(131.3)
Derivative hedging activity, net of tax	1.4			0.0
Ending balance (in shares) at Mar. 31, 2022		229,476,558			1
Ending balance at Mar. 31, 2022	$ 9,237.5	$ 7,206.4	$ 2,073.3	$ 3,075.8	$ 1,563.1	$ 1,508.4	$ 4.3