Schedule I Financial Statements of Parent Company Balance Sheets (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
CURRENT ASSETS:
Cash and cash equivalents	$ 144.9	$ 23.2
Income taxes receivable	62.9	85.5
Prepaid expenses and other assets	71.9	78.2
Total Current Assets	1,624.3	1,467.7
OTHER ASSETS:
Other	527.7	511.5
TOTAL ASSETS	27,114.8	25,975.9
CURRENT LIABILITIES:
Current maturities of long-term debt	436.4	251.1
Accrued interest	123.4	122.3
Other	182.6	161.6
Total Current Liabilities	2,355.8	2,335.9
LONG-TERM LIABILITIES:
Long-term debt, net	9,190.9	8,746.7
Other	308.2	340.7
Total Long-Term Liabilities	16,040.5	15,094.7
Commitments and Contingencies (Note 15)
Evergy, Inc. Shareholders' Equity:
Common stock - 600,000,000 shares authorized, without par value, 226,836,670 and 226,641,443 shares issued	7,080.0	7,070.4
Retained earnings	1,702.8	1,551.5
Accumulated other comprehensive loss	(49.4)	(50.0)
Total Evergy, Inc. Shareholders' Equity	8,733.4	8,571.9
TOTAL LIABILITIES AND EQUITY	27,114.8	25,975.9
Parent
CURRENT ASSETS:
Cash and cash equivalents	11.0	11.6
Accounts receivable from subsidiaries	54.1	24.5
Notes receivable from subsidiaries	349.4	2.0
Income taxes receivable	7.4	8.0
Prepaid expenses and other assets	1.9	2.4
Total Current Assets	423.8	48.5
OTHER ASSETS:
Investment in subsidiaries	10,349.2	10,023.1
Note receivable from subsidiaries	287.5	634.9
Deferred income taxes	20.5	34.2
Other	0.5	0.9
Total Other Assets	10,657.7	10,693.1
TOTAL ASSETS	11,081.5	10,741.6
CURRENT LIABILITIES:
Current maturities of long-term debt	350.0	0.0
Notes payable	200.0	20.0
Related party payables	18.4	13.1
Accrued interest	13.9	14.6
Other	11.0	8.1
Total Current Liabilities	593.3	55.8
LONG-TERM LIABILITIES:
Long-term debt, net	1,875.7	2,223.7
Other	11.7	16.9
Total Long-Term Liabilities	1,887.4	2,240.6
Commitments and Contingencies (Note 15)
Evergy, Inc. Shareholders' Equity:
Common stock - 600,000,000 shares authorized, without par value, 226,836,670 and 226,641,443 shares issued	7,063.2	7,053.7
Retained earnings	1,587.0	1,441.5
Accumulated other comprehensive loss	(49.4)	(50.0)
Total Evergy, Inc. Shareholders' Equity	8,600.8	8,445.2
TOTAL LIABILITIES AND EQUITY	$ 11,081.5	$ 10,741.6