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, 2022		229,546,105			1
Beginning balance at Dec. 31, 2022	$ 9,493.3	$ 7,219.7	$ 2,298.5	$ 3,186.3	$ 1,563.1	$ 1,619.2	$ 4.0
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	145.7		142.6	46.8		46.8
Dividends declared on common stock	(140.7)		(140.7)
Derivative hedging activity, net of tax	1.3			(0.1)			(0.1)
Ending balance (in shares) at Mar. 31, 2023		229,676,699			1
Ending balance at Mar. 31, 2023	9,501.7	$ 7,222.2	2,300.0	3,233.0	$ 1,563.1	1,666.0	3.9
Beginning balance (in shares) at Dec. 31, 2023		229,729,296			1
Beginning balance at Dec. 31, 2023	9,685.0	$ 7,234.9	2,457.8	3,193.0	$ 1,563.1	1,626.2	3.7
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	125.8		122.7	32.7		32.7
Dividends declared on common stock	(147.7)		(147.7)
Derivative hedging activity, net of tax	1.3			(0.1)			(0.1)
Ending balance (in shares) at Mar. 31, 2024		229,922,338			1
Ending balance at Mar. 31, 2024	$ 9,664.1	$ 7,235.0	$ 2,432.4	$ 3,225.6	$ 1,563.1	$ 1,658.9	$ 3.6