Consolidated Balance Sheets - USD ($) $ in Millions	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017
CURRENT ASSETS:
Cash and cash equivalents	$ 50.1			$ 160.3
Receivables, net	268.8			193.7
Accounts receivable pledged as collateral	395.0			365.0
Fuel inventory and supplies	454.4			511.0
Income taxes receivable	65.3			68.0
Regulatory assets	204.8			303.9
Prepaid expenses and other assets	73.9			79.1
Total Current Assets	1,512.3			1,681.0
PROPERTY, PLANT AND EQUIPMENT, NET	18,976.1			18,782.5
OTHER ASSETS:
Regulatory assets	1,869.7			1,757.9
Nuclear decommissioning trust fund	541.0			472.1
Goodwill	2,336.6			2,338.9
Other	508.0			396.5
Total Other Assets	5,255.3			4,965.4
TOTAL ASSETS	25,907.5			25,598.1
CURRENT LIABILITIES:
Current maturities of long-term debt	251.1			705.4
Notes payable and commercial paper	360.6			738.6
Collateralized note payable	395.0			365.0
Accounts payable	311.3			451.5
Accrued taxes	287.9			133.6
Accrued interest	110.7			110.9
Regulatory liabilities	59.6			110.2
Asset retirement obligations	58.2			49.8
Other	208.4			171.9
Total Current Liabilities	2,075.1			2,867.2
LONG-TERM LIABILITIES:
Long-term debt, net	8,749.2			6,636.3
Deferred income taxes	1,729.6			1,599.2
Unamortized investment tax credits	370.3			373.2
Regulatory liabilities	2,227.5			2,218.8
Pension and post-retirement liability	1,149.6			987.6
Asset retirement obligations	659.1			637.3
Other	338.4			236.7
Total Long-Term Liabilities	15,242.5			12,740.2
Commitments and Contingencies (Note 11)
Evergy, Inc. Shareholders' Equity:
Common stock	7,066.9			8,685.2
Retained earnings	1,603.1			1,346.0
Accumulated other comprehensive loss	(50.7)			(3.0)
Total Shareholders' Equity	8,619.3			10,028.2
Noncontrolling Interests	(29.4)			(37.5)
Total Equity	8,589.9	$ 8,854.7	$ 9,391.7	9,990.7	$ 10,648.8	$ 10,895.4	$ 3,864.4	$ 3,860.4
TOTAL LIABILITIES AND EQUITY	25,907.5			25,598.1
Variable Interest Entities
CURRENT ASSETS:
PROPERTY, PLANT AND EQUIPMENT, NET	163.8			169.2
CURRENT LIABILITIES:
Current maturities of long-term debt	32.3			30.3
LONG-TERM LIABILITIES:
Long-term debt, net	$ 18.8			$ 51.1