CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
CURRENT ASSETS
Cash and cash equivalents	$ 0.0	$ 1.1
Accounts Receivable, after Allowance for Credit Loss, Current	139.5	157.8
Accrued unbilled revenues	59.9	67.6
Income taxes receivable	6.4	8.1
Fuel inventories	39.4	36.5
Materials and supplies, at average cost	121.9	116.2
Fuel clause under recoveries	91.8	0.0
Other	43.8	41.2
Total current assets	502.7	428.5
OTHER PROPERTY AND INVESTMENTS
Investment in unconsolidated affiliates	432.8	397.4
Other	86.4	86.7
Total other property and investments	519.2	484.1
PROPERTY, PLANT AND EQUIPMENT
In service	13,420.4	13,296.7
Construction work in progress	185.6	145.5
Total property, plant and equipment	13,606.0	13,442.2
Less: accumulated depreciation	4,131.5	4,067.6
Property, Plant and Equipment, Net	9,474.5	9,374.6
DEFERRED CHARGES AND OTHER ASSETS
Regulatory assets	1,269.7	415.6
Other	22.6	16.0
Total deferred charges and other assets	1,292.3	431.6
TOTAL ASSETS	11,788.7	10,718.8
CURRENT LIABILITIES
Short-term Debt	1,278.0	95.0
Accounts payable	244.8	251.5
Dividends payable	80.6	80.5
Customer deposits	80.7	81.1
Accrued taxes	37.7	55.7
Accrued interest	40.6	40.2
Accrued compensation	24.3	31.1
Fuel clause over recoveries	15.5	28.6
Other	34.3	33.7
Total current liabilities	1,836.5	697.4
LONG-TERM DEBT	3,495.0	3,494.4
DEFERRED CREDITS AND OTHER LIABILITIES
Accrued benefit obligations	182.5	231.4
Deferred income taxes	1,287.9	1,268.6
Deferred investment tax credits	10.9	10.9
Regulatory liabilities	1,176.9	1,188.9
Other	193.5	195.4
Total deferred credits and other liabilities	2,851.7	2,895.2
Total liabilities	8,183.2	7,087.0
COMMITMENTS AND CONTINGENCIES (NOTE 14)
STOCKHOLDERS' EQUITY
Common stockholders' equity	1,118.6	1,124.6
Retained earnings	2,515.6	2,544.6
Accumulated other comprehensive loss, net of tax	(28.6)	(32.1)
Total stockholders' equity	3,605.5	3,631.8
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	11,788.7	10,718.8
Treasury Stock, Carrying Basis	(0.1)	(5.3)
OG&E [Member]
CURRENT ASSETS
Cash and cash equivalents	0.0	0.0
Accounts Receivable, after Allowance for Credit Loss, Current	136.4	156.3
Accrued unbilled revenues	59.9	67.7
Materials and supplies, at average cost	121.9	116.2
Fuel clause under recoveries	91.8	0.0
Other	36.3	36.9
Total current assets	485.7	685.6
OTHER PROPERTY AND INVESTMENTS
Other	4.0	4.1
PROPERTY, PLANT AND EQUIPMENT
In service	13,414.3	13,290.6
Construction work in progress	185.6	145.5
Total property, plant and equipment	13,599.9	13,436.1
Less: accumulated depreciation	4,131.5	4,067.6
Property, Plant and Equipment, Net	9,468.4	9,368.5
DEFERRED CHARGES AND OTHER ASSETS
Regulatory assets	1,269.7	415.6
Other	20.4	15.2
Total deferred charges and other assets	1,290.1	430.8
TOTAL ASSETS	11,248.2	10,489.0
CURRENT LIABILITIES
Accounts payable	229.4	236.7
Advances from parent	297.1	0.0
Customer deposits	80.7	81.1
Accrued taxes	34.9	53.3
Accrued interest	40.3	40.2
Accrued compensation	18.0	22.5
Fuel clause over recoveries	15.5	28.6
Other	34.3	33.5
Total current liabilities	750.2	495.9
LONG-TERM DEBT	3,495.0	3,494.4
DEFERRED CREDITS AND OTHER LIABILITIES
Accrued benefit obligations	101.3	135.4
Deferred income taxes	1,030.9	1,020.8
Deferred investment tax credits	10.9	10.9
Regulatory liabilities	1,176.9	1,188.9
Other	165.7	167.1
Total deferred credits and other liabilities	2,485.7	2,523.1
Total liabilities	6,730.9	6,513.4
STOCKHOLDERS' EQUITY
Common stockholders' equity	1,570.0	1,039.5
Retained earnings	2,947.3	2,936.1
Total stockholders' equity	4,517.3	3,975.6
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	11,248.2	10,489.0
Deferred income taxes and investment tax credits, net	0.0	272.0
Fuel inventories	$ (39.4)	$ (36.5)