Oklahoma Gas And Electric 10-K 24 Feb 22 2021 FY Annual report Financial data

Document and Entity Information

Document and Entity Information Document - USD ($)	12 Months Ended
	Dec. 31, 2021	Jun. 30, 2021
Document Information [Line Items]
Entity Registrant Name	OGE ENERGY CORP.
Entity Central Index Key	0001021635
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Period End Date	Dec. 31, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Shell Company	false
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Incorporation, State or Country Code	OK
Entity Tax Identification Number	73-1481638
Entity Address, Address Line One	321 North Harvey
Entity Address, Address Line Two	P.O. Box 321
Trading Symbol	OGE
Security Exchange Name	NYSE
Entity Interactive Data Current	Yes
City Area Code	405
Local Phone Number	553-3000
Entity Address, State or Province	OK
Entity Address, Postal Zip Code	73101-0321
Entity File Number	1-12579
Title of 12(b) Security	Common Stock
Entity Address, City or Town	Oklahoma City
Share Price		$ 33.65
Document Transition Report	false
Document Annual Report	true
ICFR Auditor Attestation Flag	true
Document Type	10-K
Entity Common Stock, Shares Outstanding	200,201,818	200,174,361
Entity Public Float	$ 6,735,867,248
Og and E [Member]
Document Information [Line Items]
Entity Registrant Name	OKLAHOMA GAS AND ELECTRIC COMPANY
Entity Central Index Key	0000074145
Entity Filer Category	Non-accelerated Filer
Entity Small Business	false
Entity Shell Company	false
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Tax Identification Number	73-0382390
Entity Interactive Data Current	Yes
Entity File Number	1-1097
ICFR Auditor Attestation Flag	true
Entity Common Stock, Shares Outstanding	40,378,745

Audit Information

Audit Information	12 Months Ended
	Dec. 31, 2021
Auditor [Line Items]
Auditor Name	Ernst & Young LLP
Auditor Firm ID	42
Auditor Location	Oklahoma City, Oklahoma
Og and E [Member]
Auditor [Line Items]
Auditor Name	Ernst & Young LLP
Auditor Firm ID	42
Auditor Location	Oklahoma City, Oklahoma
Enable Midstream
Auditor [Line Items]
Auditor Name	Deloitte & Touche LLP
Auditor Firm ID	34
Auditor Location	Oklahoma City, Oklahoma

CONSOLIDATED STATEMENTS OF INCO

CONSOLIDATED STATEMENTS OF INCOME - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2021		Dec. 31, 2020		Dec. 31, 2019
Revenue from Contract with Customer, Excluding Assessed Tax	$ 3,588.7	[1]	$ 2,069.8		$ 2,175.5
Revenues from Alternative Revenue Programs	65		52.5		56.1
OPERATING REVENUES
Total operating revenues	3,653.7		2,122.3		2,231.6
Total cost of sales	2,127.6		644.6		786.9
OPERATING EXPENSES
Other operation and maintenance	463.1		462.8		491.8
Depreciation and amortization	416		391.3		355
Taxes other than income	102.8		101.4		93.6
Operating expenses	981.9		955.5		940.4
Operating income (loss)	544.2		522.2		504.3
OTHER INCOME (EXPENSE)
Equity in earnings (losses) of unconsolidated affiliates	169.8		(668)	[2],[3]	113.9	[2]
Allowance for equity funds used during construction	6.7		4.8		4.5
Pension and Other Postretirement Benefits Cost (Reversal of Cost)	(6.1)		(3.9)		(9.8)
Equity Securities, FV-NI, Gain (Loss)	(8.6)		0		0
Other income	26.3		37.5		21.9
Gain (Loss) on Disposition of Assets	344.4		0		0
Other expense	(39.9)		(35.2)		(23.5)
Net other income (expense)	492.6		(664.8)		107
INTEREST EXPENSE
Interest on long-term debt	154.8		152.8		138.3
Allowance for borrowed funds used during construction	(3.5)		(1.9)		(2.8)
Interest on short-term debt and other interest charges	7		7.6		12.4
Interest expense	158.3		158.5		147.9
INCOME (LOSS) BEFORE TAXES	878.5		(301.1)		463.4
INCOME TAX EXPENSE (BENEFIT)	141.2		(127.4)		29.8
NET INCOME (LOSS)	$ 737.3		$ (173.7)		$ 433.6
BASIC AVERAGE COMMON SHARES OUTSTANDING	200.1		200.1		200.1
DILUTED AVERAGE COMMON SHARES OUTSTANDING	200.3		200.1		200.7
BASIC EARNINGS (LOSS) PER AVERAGE COMMON SHARE	$ 3.68		$ (0.87)		$ 2.17
DILUTED EARNINGS (LOSS) PER AVERAGE COMMON SHARE	3.68		(0.87)		2.16
DIVIDENDS DECLARED PER COMMON SHARE	$ 1.6250		$ 1.5800		$ 1.5050
Other Comprehensive Income (Loss), Net of Tax	$ 7.3		$ (4.2)		$ 1
Og and E [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	3,588.7		2,069.8		2,175.5
Revenues from Alternative Revenue Programs	65		52.5		56.1
OPERATING REVENUES
Total operating revenues	3,653.7		2,122.3		2,231.6
Total cost of sales	2,127.6		644.6		786.9
OPERATING EXPENSES
Other operation and maintenance	464.7		464.4		492.5
Depreciation and amortization	416		391.3		355
Taxes other than income	99.3		97.2		89.5
Operating expenses	980		952.9		937
Operating income (loss)	546.1		524.8		507.7
OTHER INCOME (EXPENSE)
Allowance for equity funds used during construction	6.7		4.8		4.5
Pension and Other Postretirement Benefits Cost (Reversal of Cost)	(4.3)		(3.1)		(1.2)
Other income	7.1		5		6.7
Other expense	(1.8)		(2.6)		(6.9)
Net other income (expense)	7.7		4.1		3.1
INTEREST EXPENSE
Interest on long-term debt	152.7		152.8		138.3
Allowance for borrowed funds used during construction	(3.5)		(1.9)		(2.8)
Interest on short-term debt and other interest charges	2.8		3.9		5
Interest expense	152		154.8		140.5
INCOME (LOSS) BEFORE TAXES	401.8		374.1		370.3
INCOME TAX EXPENSE (BENEFIT)	41.8		34.7		20.1
Net Income (Loss) Attributable to Parent	360		339.4		350.2
Other Comprehensive Income (Loss), Net of Tax	0		0		0
Comprehensive Income (Loss), Net of Tax, Attributable to Parent	$ 360		$ 339.4		$ 350.2
[1]	In February 2021, Winter Storm Uri resulted in record winter peak demand for electricity and extremely high natural gas and purchased power prices in OG&E's service territory. Operating revenues significantly increased due to increased fuel, purchased power and direct transmission expenses, which are generally recoverable from customers, as a result of Winter Storm Uri. For further discussion, see Note 16 and "Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations."
[2]	For the year ended December 31, 2020, Enable recorded a $225.0 million impairment on its SESH equity method investment. Enable estimated the fair value of this equity method investment was below the carrying value at September 30, 2020 and concluded the decline in value was other than temporary due to the expiration of a transportation contract and the current status of renewal negotiations. The impairment ran through OGE Energy's portion of Enable net income and was offset by basis differences that flow through the amortization of basis difference and dilution recognition line item above
[3]	In March 2020, OGE Energy recorded a $780.0 million impairment on its investment in Enable, as further discussed in Notes 5 and 7.

CONSOLIDATED STATEMENTS OF COMP

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Net income (loss)	$ 737.3	$ (173.7)	$ 433.6
Pension Plan and Restoration of Retirement Income Plan:
Amortization of prior service cost, net of tax of $0.0, $0.0 and $0.0, respectively	0.1	0	0
Amortization of deferred net loss, net of tax of $0.9, $1.2 and $1.1, respectively	1.6	3.9	3.4
Net gain (loss) arising during the period, net of tax of $0.0, ($1.7) and ($2.5), respectively	1.4	(5.1)	(8.1)
Prior service cost arising during the period, net of tax of ($0.3), $0.0 and ($0.1), respectively	(1.1)	0	(0.2)
Settlement cost, net of tax of $2.7, $0.7 and $2.7, respectively	6	2.2	8.6
Postretirement benefit plans:
Amortization of prior service credit, net of tax of ($0.4), ($0.6) and ($0.6), respectively	(1.4)	(1.7)	(1.7)
Amortization of deferred net gain, net of tax of $0.0, $0.0 and $0.0, respectively	0.1	(0.1)	(0.2)
Net loss arising during the period, net of tax of ($0.2), ($0.8) and $(0.1), respectively	(0.7)	(2.4)	(0.2)
Curtailment cost, net of tax of $0.0, $(0.1) and $0.0, respectively	0	(0.3)	0
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), after Tax	(1.1)	0	(0.2)
Other comprehensive income (loss), net of tax	7.3	(4.2)	1
Other comprehensive gain (loss) from unconsolidated affiliates, net of tax $0.3, ($0.2) and ($0.2), respectively	1.3	(0.7)	(0.6)
Comprehensive income (loss)	$ 744.6	$ (177.9)	$ 434.6

CONSOLIDATED STATEMENTS OF CO_2

CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME Parenthetical - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Pension Plan and Restoration of Retirement Income Plan:
Amortization of deferred net loss, net of tax of $1.2, $1.1 and $1.1, respectively	$ 0.9	$ 1.2	$ 1.1
Net loss arising during the period, net of tax of ($1.7), ($2.6) and ($4.7), respectively	0	(1.7)	(2.5)
Amortization of prior service credit, net of tax of $0.0, $0.0 and $0.0, respectively	0	0	0
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Tax	(0.3)	0	(0.1)
Postretirement plans:
Amortization of deferred net gain, net of tax of $0.0, $0.0 and $0.0, respectively	0	0	0
Net gain (loss) arising during the period, net of tax of ($0.8), ($0.1) and $0.7, respectively	(0.2)	(0.8)	(0.1)
Amortization of prior service credit, net of tax of ($0.6), ($0.6) and ($0.6), respectively	(0.4)	(0.6)	(0.6)
Other Comprehensive Income (Loss), Tax, Portion Attributable to Noncontrolling Interest	0.3	(0.2)	(0.2)
Pension Plans [Member]
Pension Plan and Restoration of Retirement Income Plan:
Settlement cost, net of tax of $0.7, $2.7 and $1.6, respectively	2.7	0.7	2.7
Other Postretirement Benefits Plan [Member]
Pension Plan and Restoration of Retirement Income Plan:
Settlement cost, net of tax of $0.7, $2.7 and $1.6, respectively	$ 0	$ (0.1)	$ 0

CONSOLIDATED STATEMENTS OF CASH

CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020		Dec. 31, 2019
CASH FLOWS FROM OPERATING ACTIVITIES
Net income (loss)	$ 737.3	$ (173.7)		$ 433.6
Gain (Loss) on Disposition of Assets	(353)	0		0
Adjustments to reconcile net income (loss) to net cash (used in) provided from operating activities:
Depreciation and amortization	416	391.3		355
Deferred income taxes and other tax credits, net	125.9	(134.5)		27.6
Equity in (earnings) losses of unconsolidated affiliates	(169.8)	668	[1],[2]	(113.9)	[1]
Distributions from unconsolidated affiliates	73.4	91.7		125.5
Unrealized Gain (Loss) on Investments	8.6	0		0
Allowance for equity funds used during construction	(6.7)	(4.8)		(4.5)
Stock-based compensation expense	9.8	9.8		13.9
Regulatory assets	874.9	112		47.1
Regulatory liabilities	(71.2)	(64)		(45.6)
Other assets	(9.8)	(9.2)		(3.8)
Other liabilities	(8.1)	(26.3)		19.2
Change in certain current assets and liabilities:
Accounts receivable and accrued unbilled revenues, net	(1.9)	3.1		18.8
Income taxes receivable	5.5	2.8		(1)
Fuel, materials and supplies inventories	(3.4)	(8.9)		4.2
Fuel recoveries	(180.5)	63.3		(33)
Other current assets	(22.7)	(16.8)		5.1
Accounts payable	7.5	59.8		(34.5)
Other current liabilities	4.7	(26.8)		(38)
Net cash (used in) provided from operating activities	(313.3)	712.8		681.5
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures (less allowance for equity funds used during construction)	(778.5)	(650.5)		(635.5)
Other	(5.6)	(4.4)		(7.7)
Return of capital - unconsolidated affiliates	0	0		18.5
Proceeds from Divestiture of Businesses and Interests in Affiliates	35	0		0
Net cash used in investing activities	(749.1)	(654.9)		(624.7)
CASH FLOWS FROM FINANCING ACTIVITIES
Increase (decrease) in short-term debt	391.9	(17)		112
Proceeds from long-term debt	997.8	297.1		296.5
Payment of long-term debt	(0.1)	(0.1)		(250.1)
Dividends paid on common stock	(324.9)	(314.9)		(299.2)
Cash paid for employee equity-based compensation and expense of common stock	(3.4)	(7.1)		(10.3)
Other	0	(0.1)		0
Purchase of treasury stock	0	(14.7)		0
Net cash provided from (used in) financing activities	1,061.3	(56.8)		(151.1)
NET CHANGE IN CASH AND CASH EQUIVALENTS	(1.1)	1.1		(94.3)
CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR	1.1	0		94.3
CASH AND CASH EQUIVALENTS AT END OF YEAR	0	1.1		0
Interest costs capitalized	3.5	1.9		2.8
Interest (net of interest capitalized)	156.4	153.4		152.2
Income taxes (net of income tax refunds)	8.7	3.9		5.5
Power plant long-term service agreement	2.4	6.8		28.9
Noncash or Part Noncash Acquisition, Investments Acquired	793.7	0		0
Og and E [Member]
Adjustments to reconcile net income (loss) to net cash (used in) provided from operating activities:
Depreciation and amortization	416	391.3		355
Deferred income taxes and other tax credits, net	44.6	40.9		20.4
Allowance for equity funds used during construction	(6.7)	(4.8)		(4.5)
Stock-based compensation expense	2.2	3		4.9
Regulatory assets	874.9	112		47.1
Regulatory liabilities	(71.2)	(64)		(45.6)
Other assets	(2.2)	(3.4)		3.8
Other liabilities	(11.2)	(24.3)		8.4
Change in certain current assets and liabilities:
Accounts receivable and accrued unbilled revenues, net	(3)	4.5		17
Fuel, materials and supplies inventories	(3.4)	(8.9)		4.2
Fuel recoveries	(180.5)	63.3		(33)
Other current assets	(21.4)	(17.3)		5.9
Accounts payable	(11)	64.8		(30)
Other current liabilities	3.3	(26.8)		(35.1)
Net cash (used in) provided from operating activities	(358.7)	640.4		573.8
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures (less allowance for equity funds used during construction)	(778.5)	(650.5)		(635.5)
Net cash used in investing activities	(778.5)	(650.5)		(635.5)
Proceeds from Contributions from Parent	530	0		0
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from long-term debt	499.8	297.1		296.5
Payment of long-term debt	(0.1)	(0.1)		(250.1)
Dividends paid on common stock	(265)	(325)		0
Net cash provided from (used in) financing activities	1,137.2	10.1		61.7
NET CHANGE IN CASH AND CASH EQUIVALENTS	0	0		0
CASH AND CASH EQUIVALENTS AT BEGINNING OF YEAR	0	0		0
CASH AND CASH EQUIVALENTS AT END OF YEAR	0	0		0
Interest costs capitalized	3.5	1.9		2.8
Net Income (Loss) Attributable to Parent	360	339.4		350.2
Increase (Decrease) in Income Taxes Payable	0.7	(5.3)		(0.7)
Changes In Advances With Parent	372.5	38.1		15.3
Interest (net of interest capitalized)	148.9	150.2		144.6
Income taxes (net of income tax refunds)	(3.2)	(0.2)		1.3
Power plant long-term service agreement	$ 2.4	$ 6.8		$ 28.9
[1]	For the year ended December 31, 2020, Enable recorded a $225.0 million impairment on its SESH equity method investment. Enable estimated the fair value of this equity method investment was below the carrying value at September 30, 2020 and concluded the decline in value was other than temporary due to the expiration of a transportation contract and the current status of renewal negotiations. The impairment ran through OGE Energy's portion of Enable net income and was offset by basis differences that flow through the amortization of basis difference and dilution recognition line item above
[2]	In March 2020, OGE Energy recorded a $780.0 million impairment on its investment in Enable, as further discussed in Notes 5 and 7.

CONSOLIDATED BALANCE SHEETS

CONSOLIDATED BALANCE SHEETS - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
CURRENT ASSETS
Cash and cash equivalents	$ 0	$ 1.1	$ 0	$ 94.3
Accounts receivable, after allowance for doubtful accounts	162.3	157.8
Accrued unbilled revenues	65	67.6
Income taxes receivable	2.6	8.1
Fuel inventories	40.6	36.5
Materials and supplies, at average cost	117.9	116.2
Fuel clause under recoveries	151.9	0
Other	73.3	41.2
Total current assets	613.6	428.5
OTHER PROPERTY AND INVESTMENTS
Investment in unconsolidated affiliates	0	374.3	1,132.9
Equity Securities, FV-NI, Current	785.1	0
Other	120	109.8
Total other property and investments	905.1	484.1
PROPERTY, PLANT AND EQUIPMENT
In service	13,899.8	13,296.7
Construction work in progress	252	145.5
Total property, plant and equipment	14,151.8	13,442.2
Less: accumulated depreciation	4,318.9	4,067.6
Net property, plant and equipment	9,832.9	9,374.6
DEFERRED CHARGES AND OTHER ASSETS
Regulatory assets	1,230.8	415.6
Other	24	16
Total deferred charges and other assets	1,254.8	431.6
TOTAL ASSETS	12,606.4	10,718.8	11,024.3
Allowance for Doubtful Accounts Receivable	2.4	2.6
CURRENT LIABILITIES
Short-term debt	486.9	95
Accounts payable	274	251.5
Dividends payable	82.1	80.5
Customer deposits	81.1	81.1
Accrued taxes	52.9	55.7
Accrued interest	40.8	40.2
Accrued compensation	37.7	31.1
Long-term debt due within one year	0	0
Fuel clause over recoveries	0	28.6
Other	34.1	33.7
Total current liabilities	1,089.6	697.4
LONG-TERM DEBT	4,496.4	3,494.4
DEFERRED CREDITS AND OTHER LIABILITIES
Accrued benefit obligations	159.8	231.4
Deferred income taxes	1,333.3	1,268.6
Accumulated Deferred Investment Tax Credit	12.8	10.9
Regulatory liabilities	1,231.1	1,188.9
Other	227.1	195.4
Total deferred credits and other liabilities	2,964.1	2,895.2
Total liabilities	8,550.1	7,087
COMMITMENTS AND CONTINGENCIES (NOTE 15)
STOCKHOLDERS' EQUITY
Common stockholders' equity	1,125.8	1,124.6
Retained earnings	2,955.4	2,544.6
Accumulated other comprehensive loss, net of tax	(24.8)	(32.1)	(27.9)
Stockholders' Equity Attributable to Parent	4,056.3	3,631.8
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	12,606.4	10,718.8
Og and E [Member]
CURRENT ASSETS
Cash and cash equivalents	0	0	0	0
Accounts receivable, after allowance for doubtful accounts	162	156.3
Accrued unbilled revenues	65	67.7
Advances to parent	0	272
Fuel inventories	40.6	36.5
Materials and supplies, at average cost	117.9	116.2
Fuel clause under recoveries	151.9	0
Other	67.7	36.9
Total current assets	605.1	685.6
OTHER PROPERTY AND INVESTMENTS
Total other property and investments	3.9	4.1
PROPERTY, PLANT AND EQUIPMENT
In service	13,893.7	13,290.6
Construction work in progress	252	145.5
Total property, plant and equipment	14,145.7	13,436.1
Less: accumulated depreciation	4,318.9	4,067.6
Net property, plant and equipment	9,826.8	9,368.5
DEFERRED CHARGES AND OTHER ASSETS
Regulatory assets	1,230.8	415.6
Other	21.4	15.2
Total deferred charges and other assets	1,252.2	430.8
TOTAL ASSETS	11,688	10,489
CURRENT LIABILITIES
Accounts payable	240.6	236.7
Advances from parent	101.3	0
Customer deposits	81.1	81.1
Accrued taxes	50.8	53.3
Accrued interest	40.4	40.2
Accrued compensation	27.8	22.5
Long-term debt due within one year	0	0
Fuel clause over recoveries	0	28.6
Other	33.8	33.5
Total current liabilities	575.8	495.9
LONG-TERM DEBT	3,996.5	3,494.4
DEFERRED CREDITS AND OTHER LIABILITIES
Accrued benefit obligations	75.1	135.4
Deferred income taxes	1,000.4	1,020.8
Accumulated Deferred Investment Tax Credit	12.8	10.9
Regulatory liabilities	1,231.1	1,188.9
Other	193.5	167.1
Total deferred credits and other liabilities	2,512.9	2,523.1
Total liabilities	7,085.2	6,513.4
COMMITMENTS AND CONTINGENCIES (NOTE 15)
STOCKHOLDERS' EQUITY
Common stockholders' equity	1,571.7	1,039.5
Retained earnings	3,031.1	2,936.1
Stockholders' Equity Attributable to Parent	4,602.8	3,975.6	$ 3,958.3	$ 3,603.3
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$ 11,688	$ 10,489

CONSOLIDATED BALANCE SHEETS Par

CONSOLIDATED BALANCE SHEETS Parenthetical - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Allowance for Doubtful Accounts Receivable	$ 2.4	$ 2.6

CONSOLIDATED STATEMENTS OF CAPI

CONSOLIDATED STATEMENTS OF CAPITALIZATION - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Schedule of Capitalization, Long-term Debt [Line Items]
Common Stock, Value	$ 2	$ 2
Premium on common stock	1,123.8	1,122.6
Retained earnings	2,955.4	2,544.6
Accumulated other comprehensive loss, net of tax	$ (24.8)	$ (32.1)
Treasury Stock, Common, Shares	0	0.1
Treasury Stock, Value	$ (0.1)	$ (5.3)
Total stockholders' equity	4,056.3	3,631.8
Unamortized debt expense	(23.8)	(25.3)
Total long-term debt	4,496.4	3,494.4
Less: long-term debt due within one year	0	0
Total long-term debt (excluding long-term debt due within one year)	4,496.4	3,494.4
Total capitalization (including long-term debt due within one year)	$ 8,552.7	$ 7,126.2
Common Stock, Par or Stated Value Per Share	$ 0.01	$ 0.01
Common Stock, Shares Authorized	450	450
Common Stock, Shares, Outstanding	200.1	200.1
Og and E [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Common Stock, Value	$ 100.9	$ 100.9
Premium on common stock	1,470.8	938.6
Retained earnings	3,031.1	2,936.1
Total stockholders' equity	4,602.8	3,975.6
Unamortized debt expense	(23.7)	(25.3)
Unamortized discount	(9.5)	(10.1)
Total long-term debt	3,996.5	3,494.4
Less: long-term debt due within one year	0	0
Total long-term debt (excluding long-term debt due within one year)	3,996.5	3,494.4
Total capitalization (including long-term debt due within one year)	$ 8,599.3	$ 7,470
Common Stock, Par or Stated Value Per Share	$ 2.50	$ 2.50
Common Stock, Shares Authorized	100	100
Common Stock, Shares, Outstanding	40.4	40.4
Garfield Industrial Authority Bond [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Debt Instrument, Maturity Date	Jan. 1, 2025
Muskogee Industrial Authority Bond Due 2025 [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Debt Instrument, Maturity Date	Jan. 1, 2025
Muskogee Industrial Authority Bond Due 2027 [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Debt Instrument, Maturity Date	Jun. 1, 2027
Senior Notes [Member] | Series Due July 15, 2027 [Member] | Og and E [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Long-term Debt, Gross	$ 125	$ 125
Debt Instrument, Interest Rate, Stated Percentage	6.65%
Debt Instrument, Maturity Date	Jul. 15, 2027
Senior Notes [Member] | Series Due April 15, 2028 [Member] | Og and E [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Long-term Debt, Gross	$ 100	100
Debt Instrument, Interest Rate, Stated Percentage	6.50%
Debt Instrument, Maturity Date	Apr. 15, 2028
Senior Notes [Member] | Series Due August 15, 2028 [Member] [Member] | Og and E [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Long-term Debt, Gross	$ 400	400
Debt Instrument, Interest Rate, Stated Percentage	3.80%
Senior Notes [Member] | Series Due March 15, 2030 | Og and E [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Long-term Debt, Gross	$ 300	300
Debt Instrument, Interest Rate, Stated Percentage	3.30%
Debt Instrument, Maturity Date	Mar. 15, 2030
Senior Notes [Member] | Series Due January 15, 2036 [Member] | Og and E [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Long-term Debt, Gross	$ 110	110
Debt Instrument, Interest Rate, Stated Percentage	5.75%
Debt Instrument, Maturity Date	Jan. 15, 2036
Senior Notes [Member] | Series Due February 1, 2038 [Member] | Og and E [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Long-term Debt, Gross	$ 200	200
Debt Instrument, Interest Rate, Stated Percentage	6.45%
Debt Instrument, Maturity Date	Feb. 1, 2038
Senior Notes [Member] | Series Due June 1, 2040 [Member] | Og and E [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Long-term Debt, Gross	$ 250	250
Debt Instrument, Interest Rate, Stated Percentage	5.85%
Debt Instrument, Maturity Date	Jun. 1, 2040
Senior Notes [Member] | Series Due May 15, 2041 [Member] | Og and E [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Long-term Debt, Gross	$ 250	250
Debt Instrument, Interest Rate, Stated Percentage	5.25%
Debt Instrument, Maturity Date	May 15, 2041
Senior Notes [Member] | Series Due May 1, 2043 [Member] | Og and E [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Long-term Debt, Gross	$ 250	250
Debt Instrument, Interest Rate, Stated Percentage	3.90%
Debt Instrument, Maturity Date	May 1, 2043
Senior Notes [Member] | Series Due March 15, 2044 [Member] | Og and E [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Long-term Debt, Gross	$ 250	250
Debt Instrument, Interest Rate, Stated Percentage	4.55%
Debt Instrument, Maturity Date	Mar. 15, 2044
Senior Notes [Member] | Series Due December 15, 2044 [Member] | Og and E [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Long-term Debt, Gross	$ 250	250
Debt Instrument, Interest Rate, Stated Percentage	4.00%
Debt Instrument, Maturity Date	Dec. 15, 2044
Senior Notes [Member] | Series due August 15, 2047 [Member] [Domain] | Og and E [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Long-term Debt, Gross	$ 300	300
Debt Instrument, Interest Rate, Stated Percentage	3.85%
Debt Instrument, Maturity Date	Aug. 15, 2047
Senior Notes [Member] | Series due April 1, 2047 [Member] | Og and E [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Long-term Debt, Gross	$ 300	300
Debt Instrument, Interest Rate, Stated Percentage	4.15%
Debt Instrument, Maturity Date	Apr. 1, 2047
Senior Notes [Member] | Series Due April 1, 2030 | Og and E [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Long-term Debt, Gross	$ 300	300
Debt Instrument, Interest Rate, Stated Percentage	3.25%
Debt Instrument, Maturity Date	Apr. 1, 2030
Senior Notes [Member] | Series due August 15, 2028 [Member] | Og and E [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Debt Instrument, Maturity Date	Aug. 15, 2028
Senior Notes [Member] | Series Due May 26, 2023 | OGE Energy [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Long-term Debt, Gross	$ 500	0
Debt Instrument, Interest Rate, Stated Percentage	0.703%
Debt Instrument, Maturity Date	May 26, 2023
Senior Notes [Member] | Series Due May 26, 2023 | Og and E [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Long-term Debt, Gross	$ 500	0
Debt Instrument, Interest Rate, Stated Percentage	0.553%
Debt Instrument, Maturity Date	May 26, 2023
Long-term Debt [Member] | Due August 31, 2062 [Member] | Og and E [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Long-term Debt, Gross	$ 9.3	9.4
Debt Instrument, Interest Rate, Stated Percentage	3.80%
Debt Instrument, Maturity Date	Aug. 31, 2062
Debentures Subject to Mandatory Redemption [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Total long-term debt	$ 135.4
Debentures Subject to Mandatory Redemption [Member] | Garfield Industrial Authority Bond [Member] | Minimum [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	0.11%
Debentures Subject to Mandatory Redemption [Member] | Garfield Industrial Authority Bond [Member] | Maximum [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	0.27%
Debentures Subject to Mandatory Redemption [Member] | Garfield Industrial Authority Bond [Member] | Og and E [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Long-term Debt, Gross	$ 47	47
Debentures Subject to Mandatory Redemption [Member] | Muskogee Industrial Authority Bond Due 2025 [Member] | Minimum [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	0.11%
Debentures Subject to Mandatory Redemption [Member] | Muskogee Industrial Authority Bond Due 2025 [Member] | Maximum [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	0.33%
Debentures Subject to Mandatory Redemption [Member] | Muskogee Industrial Authority Bond Due 2025 [Member] | Og and E [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Long-term Debt, Gross	$ 32.4	32.4
Debentures Subject to Mandatory Redemption [Member] | Muskogee Industrial Authority Bond Due 2027 [Member] | Minimum [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	0.11%
Debentures Subject to Mandatory Redemption [Member] | Muskogee Industrial Authority Bond Due 2027 [Member] | Maximum [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	0.27%
Debentures Subject to Mandatory Redemption [Member] | Muskogee Industrial Authority Bond Due 2027 [Member] | Og and E [Member]
Schedule of Capitalization, Long-term Debt [Line Items]
Long-term Debt, Gross	$ 56	$ 56

CONSOLIDATED STATEMENTS OF CHAN

CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY - USD ($) $ in Millions	Total	Common Stock	Premium on Common Stock	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock
Common Stock, Shares, Outstanding		199,700,000
Comprehensive income (loss)
Treasury Stock, Common, Shares						0
Net Income (Loss), Including portion attributable to noncontrolling interest, Number of Shares		0				0
Balance at Dec. 31, 2018	$ 4,005.1	$ 2	$ 1,125.7	$ 2,906.3	$ (28.9)	$ 0
Comprehensive income (loss)
Net income (loss)	433.6	$ 0	0	433.6	0	$ 0
Other Comprehensive Income (Loss), Net of Tax, Number of Shares		0				0
Other Comprehensive Income (Loss), Net of Tax	1	$ 0	0	0	1	$ 0
Dividends, Common Stock, Cash, Number of Shares		0				0
Dividends declared on common stock	(303.8)	$ 0	0	(303.8)	0	$ 0
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition, Number of Shares		400,000				0
Stock-based compensation	3.6	$ 0	3.6	0	0	$ 0
Balance at Dec. 31, 2019	$ 4,139.5	$ 2	1,129.3	3,036.1	(27.9)	$ 0
Comprehensive income (loss)
DIVIDENDS DECLARED PER COMMON SHARE	$ 1.5050
Common Stock, Shares, Outstanding		200,100,000
Treasury Stock, Common, Shares						0
Net Income (Loss), Including portion attributable to noncontrolling interest, Number of Shares		0				0
Net income (loss)	$ (173.7)	$ 0	0	(173.7)	0	$ 0
Other Comprehensive Income (Loss), Net of Tax, Number of Shares		0				0
Other Comprehensive Income (Loss), Net of Tax	(4.2)	$ 0	0	0	(4.2)	$ 0
Dividends, Common Stock, Cash, Number of Shares		0				0
Dividends declared on common stock	(317.8)	$ 0	0	(317.8)	0	$ 0
Treasury Stock, Value, Acquired, Cost Method	(14.7)	$ 0	0	0	0	$ (14.7)
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition, Number of Shares		0				(300,000)
Stock-based compensation	2.7	$ 0	(6.7)	0	0	$ 9.4
Balance at Dec. 31, 2020	$ 3,631.8	$ 2	1,122.6	2,544.6	(32.1)	$ (5.3)
Comprehensive income (loss)
DIVIDENDS DECLARED PER COMMON SHARE	$ 1.5800
Treasury Stock, Shares, Acquired		0				400,000
Common Stock, Shares, Outstanding	200,100,000	200,100,000
Treasury Stock, Common, Shares	100,000					100,000
Net Income (Loss), Including portion attributable to noncontrolling interest, Number of Shares		0				0
Net income (loss)	$ 737.3	$ 0	0	737.3	0	$ 0
Other Comprehensive Income (Loss), Net of Tax, Number of Shares		0				0
Other Comprehensive Income (Loss), Net of Tax	7.3	$ 0	0	0	7.3	$ 0
Dividends, Common Stock, Cash, Number of Shares		0				0
Dividends declared on common stock	(326.5)	$ 0	0	(326.5)	0	$ 0
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition, Number of Shares		0				(100,000)
Stock-based compensation	6.4	$ 0	1.2	0	0	$ 5.2
Balance at Dec. 31, 2021	$ 4,056.3	$ 2	$ 1,123.8	$ 2,955.4	$ (24.8)	$ (0.1)
Comprehensive income (loss)
DIVIDENDS DECLARED PER COMMON SHARE	$ 1.6250
Treasury Stock, Shares, Acquired	405,000
Common Stock, Shares, Outstanding	200,100,000	200,100,000
Treasury Stock, Common, Shares	0					0

STATEMENTS OF CHANGES IN STOCKH

STATEMENTS OF CHANGES IN STOCKHOLDER'S EQUITY - USD ($) shares in Millions, $ in Millions	Total	Og and E [Member]	Common Stock	Common StockOg and E [Member]	Premium on Common Stock	Premium on Common StockOg and E [Member]	Retained Earnings	Retained EarningsOg and E [Member]
Common Stock, Shares, Outstanding			199.7	40.4
Stockholders' Equity Attributable to Parent		$ 3,603.3		$ 100.9		$ 930.9		$ 2,571.5
Net Income (Loss), Including portion attributable to noncontrolling interest, Number of Shares			0	0
Net Income (Loss) Attributable to Parent		350.2		$ 0		0		350.2
Dividends, Common Stock, Cash, Number of Shares			0	0
Dividends, Common Stock		(325)		$ 0		0		325
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition, Number of Shares			0.4	0
Stock-based compensation	$ 3.6	4.8	$ 0	$ 0	$ 3.6	4.8	$ 0	0
Common Stock, Shares, Outstanding			200.1	40.4
Stockholders' Equity Attributable to Parent		3,958.3		$ 100.9		935.7		2,921.7
Net Income (Loss), Including portion attributable to noncontrolling interest, Number of Shares			0	0
Net Income (Loss) Attributable to Parent		339.4		$ 0		0		339.4
Dividends, Common Stock, Cash, Number of Shares			0
Dividends, Common Stock								0
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition, Number of Shares			0	0
Stock-based compensation	$ 2.7	$ (2.9)	$ 0	$ 0	(6.7)	(2.9)	0	0
Common Stock, Shares, Outstanding	200.1	40.4	200.1	40.4
Stockholders' Equity Attributable to Parent	$ 3,631.8	$ 3,975.6		$ 100.9		938.6		2,936.1
Net Income (Loss), Including portion attributable to noncontrolling interest, Number of Shares			0	0
Net Income (Loss) Attributable to Parent		360		$ 0		0		360
Dividends, Common Stock, Cash, Number of Shares			0	0
Dividends, Common Stock		(265)		$ 0		0		265
Proceeds from Contributed Capital, Shares				0
Proceeds from Contributed Capital		530		$ 0		530		0
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition, Number of Shares			0	0
Stock-based compensation	$ 6.4	$ 2.2	$ 0	$ 0	$ 1.2	2.2	$ 0	0
Common Stock, Shares, Outstanding	200.1	40.4	200.1	40.4
Stockholders' Equity Attributable to Parent	$ 4,056.3	$ 4,602.8		$ 100.9		$ 1,470.8		$ 3,031.1

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	Summary of Significant Accounting Policies Organization OGE Energy is a holding company with investments in energy and energy services providers offering physical delivery and related services for electricity in Oklahoma and western Arkansas and natural gas, crude oil and NGLs across the U.S. OGE Energy conducts these activities through two business segments: (i) electric utility and (ii) natural gas midstream operations. The accounts of OGE Energy and its wholly-owned subsidiaries, including OG&E, are included in OGE Energy's consolidated financial statements. All intercompany transactions and balances are eliminated in such consolidation. OGE Energy generally uses the equity method of accounting for investments where its ownership interest is between 20 percent and 50 percent and it lacks the power to direct activities that most significantly impact economic performance. Electric Utility Operations . OGE Energy's electric utility operations are conducted through OG&E, which generates, transmits, distributes and sells electric energy in Oklahoma and western Arkansas. OG&E's rates are subject to regulation by the OCC, the APSC and the FERC. OG&E was incorporated in 1902 under the laws of the Oklahoma Territory and is a wholly-owned subsidiary of OGE Energy. OG&E is the largest electric utility in Oklahoma, and its franchised service territory includes Fort Smith, Arkansas and the surrounding communities. OG&E sold its retail natural gas business in 1928 and is no longer engaged in the natural gas distribution business. Natural Gas Midstream Operations. In February 2021, Enable entered into a definitive merger agreement with Energy Transfer, pursuant to which all outstanding common units of Enable were to be acquired by Energy Transfer in an all-equity transaction. The transaction closed on December 2, 2021, and under the terms of the merger agreement, OGE Energy received 95,389,721 common units of Energy Transfer for OGE Energy’s 110,982,805 common units of Enable. As part of the transaction, Energy Transfer also acquired the general partner interests of Enable from OGE Energy and CenterPoint for cash consideration. Upon the transaction closing, OGE Energy owned approximately three percent of Energy Transfer's outstanding limited partner units in lieu of the 25.5 percent interest in Enable that it previously owned. For periods prior to December 2, 2021, OGE Energy's natural gas midstream operations segment represented OGE Energy's investment in Enable, which OGE Energy accounted for as an equity method investment. Formed in 2013, Enable was primarily engaged in the business of gathering, processing, transporting and storing natural gas primarily in the south central U.S. For further discussion regarding Enable's business, see OGE Energy's 2020 Form 10-K . Upon the closing of the Energy Transfer and Enable merger, OGE Energy's natural gas midstream operations segment represents OGE Energy's investment in Energy Transfer's equity securities and legacy Enable seconded employee pension and postretirement costs. The investment in Energy Transfer's equity securities is held through wholly-owned subsidiaries and ultimately OGE Holdings. At December 31, 2021, OGE energy owned 95.4 million, or approximately three percent, of Energy Transfer's limited partner units. OGE Energy does not have significant influence over Energy Transfer, as OGE Energy does not own general partner units in or have board representation at Energy Transfer. As such, OGE Energy accounts for its investment in Energy Transfer as an investment in equity securities, as further discussed under "Investment in Equity Securities of Energy Transfer" below. OGE Energy intends to exit the midstream segment in a prudent manner. OGE Energy charges operating costs to OG&E, and prior to December 2, 2021, OGE Energy charged operating costs to Enable, based on several factors. Operating costs directly related to OG&E and Enable are assigned as such. Operating costs incurred for the benefit of OG&E and Enable are allocated either as overhead based primarily on labor costs or using the "Distrigas" method. The "Distrigas" method is a three-factor formula that uses an equal weighting of payroll, net operating revenues and gross property, plant and equipment. OGE Energy adopted this method as a result of a recommendation by the OCC Staff. OGE Energy believes this method provides a reasonable basis for allocating common expenses. Use of Estimates In preparing the financial statements, management is required to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and contingent liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Actual results could differ from those estimates. Changes to these assumptions and estimates could have a material effect on the Registrants' financial statements. However, the Registrants believe they have taken reasonable positions where assumptions and estimates are used in order to minimize the negative financial impact to the Registrants that could result if actual results vary from the assumptions and estimates. In management's opinion, the areas where the most significant judgment is exercised include the determination of Pension Plan assumptions, income taxes, contingency reserves, asset retirement obligations, regulatory assets and liabilities, unbilled revenues and the allowance for uncollectible accounts receivable. Cash and Cash Equivalents For purposes of the financial statements, the Registrants consider all highly liquid investments purchased with an original maturity of three months or less to be cash equivalents. These investments are carried at cost, which approximates fair value. Allowance for Uncollectible Accounts Receivable Customer balances are generally written off if not collected within six months after the final billing date. The allowance for uncollectible accounts receivable for OG&E is generally calculated by multiplying the last six months of electric revenue by the provision rate, which is based on a 12-month historical average of actual balances written off and is adjusted for current conditions and supportable forecasts as necessary. To the extent the historical collection rates, when incorporating forecasted conditions, are not representative of future collections, there could be an effect on the amount of uncollectible expense recognized, such as in response to COVID-19 impacts. Also, a portion of the uncollectible provision related to fuel within the Oklahoma jurisdiction is being recovered through the fuel adjustment clause. The allowance for uncollectible accounts receivable is a reduction to Accounts Receivable in the balance sheets and is included in Other Operation and Maintenance Expense in the statements of income. The allowance for uncollectible accounts receivable was $2.4 million and $2.6 million at December 31, 2021 and 2020, respectively. New business customers are required to provide a security deposit in the form of cash, bond or irrevocable letter of credit that is refunded when the account is closed. New residential customers whose outside credit scores indicate an elevated risk are required to provide a security deposit that is refunded based on customer protection rules defined by the OCC and the APSC. The payment behavior of all existing customers is continuously monitored, and, if the payment behavior indicates sufficient risk within the meaning of the applicable utility regulation, customers will be required to provide a security deposit. Investment in Unconsolidated Affiliates Prior to December 2, 2021, OGE Energy's investment in Enable was considered to be a variable interest entity because the owners of the equity at risk in the entity had disproportionate voting rights in relation to their obligations to absorb the entity's expected losses or to receive its expected residual returns. However, OGE Energy was not considered the primary beneficiary of Enable since it did not have the power to direct the activities of Enable that are considered most significant to the economic performance of Enable; therefore, OGE Energy accounted for its investment in Enable using the equity method of accounting. Under the equity method, the investment was adjusted each period for contributions made, distributions received and OGE Energy's share of the investee's comprehensive income as adjusted for basis differences. OGE Energy considered distributions received from Enable which did not exceed cumulative equity in earnings subsequent to the date of investment to be a return on investment and are classified as operating activities in the statements of cash flows. OGE Energy considered distributions received from Enable in excess of cumulative equity in earnings subsequent to the date of investment to be a return of investment and are classified as investing activities in the statements of cash flows. Allowance for Funds Used During Construction Collection of Sales Tax In the normal course of its operations, OG&E collects sales tax from its customers. OG&E records a current liability for sales taxes when it bills its customers and eliminates this liability when the taxes are remitted to the appropriate governmental authorities. OG&E excludes the sales tax collected from its operating revenues. Revenue Recognition General OG&E recognizes revenue from electric sales when power is delivered to customers. The performance obligation to deliver electricity is generally created and satisfied simultaneously, and the provisions of the regulatory-approved tariff determine the charges OG&E may bill the customer, payment due date and other pertinent rights and obligations of both parties. OG&E measures its customers' metered usage and sends bills to its customers throughout each month. As a result, there is a significant amount of customers' electricity consumption that has not been billed at the end of each month. OG&E accrues an estimate of the revenues for electric sales delivered since the latest billings. Unbilled revenue is presented in Accrued Unbilled Revenues in the balance sheets and in Revenues from Contracts with Customers in the statements of income based on estimates of usage and prices during the period. The estimates that management uses in this calculation could vary from the actual amounts to be paid by customers. Integrated Market and Transmission OG&E currently owns and operates transmission and generation facilities as part of a vertically integrated utility. OG&E is a member of the SPP regional transmission organization and has transferred operational authority, but not ownership, of OG&E's transmission facilities to the SPP. The SPP has implemented FERC-approved regional day-ahead and real-time markets for energy and operating services, as well as associated transmission congestion rights. Collectively, the three markets operate together under the global name, SPP Integrated Marketplace. OG&E represents owned and contracted generation assets and customer load in the SPP Integrated Marketplace for the sole benefit of its customers. OG&E has not participated in the SPP Integrated Marketplace for any speculative trading activities. OG&E records the SPP Integrated Marketplace transactions as sales or purchases per FERC Order 668, which requires that purchases and sales be recorded on a net basis for each settlement period of the SPP Integrated Marketplace. Purchases and sales are based on the fixed transaction price determined by the market at the time of the purchase or sale and the MWh quantity purchased or sold. These results are reported as Revenues from Contracts with Customers or Fuel, Purchased Power and Direct Transmission Expense in the statements of income. OG&E revenues, expenses, assets and liabilities may be adversely affected by changes in the organization, operating and regulation by the FERC or the SPP. OG&E's transmission revenues are generated by the use of OG&E's transmission network by the SPP, which operates the network, on behalf of other transmission owners. OG&E recognizes revenue on the sale of transmission service to its customers over time as the service is provided in the amount OG&E has a right to invoice. Transmission service to the SPP is billed monthly based on a fixed transaction price determined by OG&E's FERC-approved formula transmission rates along with other SPP-specific charges and the megawatt quantity reserved. Other Revenues Other Revenues in the statements of income is comprised of certain rider revenue that includes alternative revenue measures as defined in ASC 980, "Regulated Operations," which details two types of alternative revenue programs. The first type adjusts billings for the effects of weather abnormalities or broad external factors or to compensate OG&E for demand-side Fuel Adjustment Clauses The actual cost of fuel used in electric generation and certain purchased power costs are generally recoverable from OG&E's customers through fuel adjustment clauses. The fuel adjustment clauses are subject to periodic review by the OCC and the APSC. Actual fuel costs from Winter Storm Uri are recoverable from OG&E's customers through securitization of regulatory assets. Both the OCC and the APSC allowed OG&E to create a regulatory asset for each jurisdictional portion of all deferred costs, as further discussed above within "Accounting Records." For additional information on Oklahoma securitization, see Note 16. Income Taxes OGE Energy files consolidated income tax returns in the U.S. federal jurisdiction and various state jurisdictions. OG&E is a part of the consolidated tax return of OGE Energy. Income taxes are generally allocated to each company in the affiliated group, including OG&E, based on its stand-alone taxable income or loss. Federal investment tax credits previously claimed on electric utility property have been deferred and will be amortized to income over the life of the related property. The Registrants use the asset and liability method of accounting for income taxes. Under this method, a deferred tax asset or liability is recognized for the estimated future tax effects attributable to temporary differences between the financial statement basis and the tax basis of assets and liabilities as well as tax credit carry forwards and net operating loss carry forwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in the period of the change. The Registrants recognize interest related to unrecognized tax benefits in Interest Expense and recognize penalties in Other Expense in the statements of income. Accrued Vacation The Registrants accrue vacation pay monthly by establishing a liability for vacation earned. Vacation may be taken as earned and is charged against the liability. At the end of each year, the liability represents the amount of vacation earned but not taken.
Comprehensive Income (Loss) Note [Text Block]	Accumulated Other Comprehensive Income (Loss) The following table presents changes in the components of accumulated other comprehensive income (loss) attributable to OGE Energy during 2020 and 2021. All amounts below are presented net of tax. Pension Plan and Restoration of Retirement Income Plan Postretirement Benefit Plans (In millions) Net Gain Prior Service Cost (Credit) Net Gain (Loss) Prior Service Cost (Credit) Other Comprehensive Gain (Loss) from Unconsolidated Affiliates Total Balance at December 31, 2019 $ (34.9) $ (0.2) $ 4.2 $ 3.6 $ (0.6) $ (27.9) Other comprehensive income (loss) before reclassifications (5.1) — (2.4) — (0.7) (8.2) Amounts reclassified from accumulated other comprehensive income (loss) 3.9 — (0.1) (1.7) — 2.1 Curtailment — — (0.3) — — (0.3) Settlement cost 2.2 — — — — 2.2 Net current period other comprehensive income (loss) 1.0 — (2.8) (1.7) (0.7) (4.2) Balance at December 31, 2020 (33.9) (0.2) 1.4 1.9 (1.3) (32.1) Other comprehensive income (loss) before reclassifications 1.4 (1.1) (0.7) — 1.3 0.9 Amounts reclassified from accumulated other comprehensive income (loss) 1.6 0.1 0.1 (1.4) — 0.4 Settlement cost 6.0 — — — — 6.0 Net current period other comprehensive income (loss) 9.0 (1.0) (0.6) (1.4) 1.3 7.3 Balance at December 31, 2021 $ (24.9) $ (1.2) $ 0.8 $ 0.5 $ — $ (24.8) The following table presents significant amounts reclassified out of accumulated other comprehensive income (loss) by the respective line items in net income (loss) during the years ended December 31, 2021 and 2020. Details about Accumulated Other Comprehensive Income (Loss) Components Amount Reclassified from Accumulated Other Comprehensive Income (Loss) Affected Line Item in Year Ended December 31, (In millions) 2021 2020 Amortization of Pension Plan and Restoration of Retirement Income Plan items: Actuarial losses $ (2.5) $ (5.1) (A) Prior service cost (0.1) — (A) Settlement cost (8.7) (2.9) (A) (11.3) (8.0) Income (Loss) Before Taxes (3.6) (1.9) Income Tax Expense (Benefit) $ (7.7) $ (6.1) Net Income (Loss) Amortization of postretirement benefit plans items: Prior service credit $ 1.8 $ 2.3 (A) Curtailment cost — 0.4 (A) Actuarial gains (losses) (0.1) 0.1 (A) 1.7 2.8 Income (Loss) Before Taxes 0.4 0.7 Income Tax Expense (Benefit) $ 1.3 $ 2.1 Net Income (Loss) Total reclassifications for the period, net of tax $ (6.4) $ (4.0) Net Income (Loss) (A) These accumulated other comprehensive income (loss) components are included in the computation of net periodic benefit cost (see Note 13 for additional information).
Asset Retirement Obligation Disclosure [Text Block]	OG&E has asset retirement obligations primarily associated with the removal of company-owned wind turbines on leased land, as well as the removal of asbestos from certain power generating stations. OG&E has recorded asset retirement obligations that are being accreted over their respective lives ranging from five to 68 years. Asset retirement obligations are included in Other Deferred Credits in the Registrants' balance sheets. The following table presents changes to OG&E's asset retirement obligations during the years ended December 31, 2021 and 2020. (In millions) 2021 2020 Balance at January 1 $ 79.6 $ 73.5 Accretion expense 0.6 0.5 Revisions in estimated cash flows (A) — 5.8 Liabilities settled (B) — (0.2) Balance at December 31 $ 80.2 $ 79.6 (A) Assumptions changed related to the estimated timing and estimated cost of the removal of asbestos at OG&E's generating facilities.
Property, Plant and Equipment Disclosure [Text Block]	Property, Plant and Equipment All property, plant and equipment is recorded at cost. Newly constructed plant is added to plant balances at cost which includes contracted services, direct labor, materials, overhead, transportation costs and the allowance for funds used during construction. Replacements of units of property are capitalized as plant. For assets that belong to a common plant account, the replaced plant is removed from plant balances, and the cost of such property net of any salvage proceeds is charged to Accumulated Depreciation. For assets that do not belong to a common plant account, the replaced plant is removed from plant balances with the related accumulated depreciation, and the remaining balance net of any salvage proceeds is recorded as a loss in the statements of income as Other Expense. Repair and replacement of minor items of property are included in the statements of income as Other Operation and Maintenance Expense. The following tables present OG&E's ownership interest in the jointly-owned McClain Plant and the jointly-owned Redbud Plant, and, as disclosed below, only OG&E's ownership interest is reflected in the property, plant and equipment and accumulated depreciation balances in these tables. The owners of the remaining interests in the McClain Plant and the Redbud Plant are responsible for providing their own financing of capital expenditures. Also, only OG&E's proportionate interests of any direct expenses of the McClain Plant and the Redbud Plant, such as fuel, maintenance expense and other operating expenses, are included in the applicable financial statement captions in the statements of income. December 31, 2021 (In millions) Percentage Ownership Total Property, Plant and Equipment Accumulated Depreciation Net Property, Plant and Equipment McClain Plant (A) 77 % $ 258.5 $ 109.0 $ 149.5 Redbud Plant (A)(B) 51 % $ 538.2 $ 203.4 $ 334.8 (A) Construction work in progress was $0.2 million and $0.2 million for the McClain and Redbud Plants, respectively. (B) This amount includes a plant acquisition adjustment of $148.3 million and accumulated amortization of $72.8 million. December 31, 2020 (In millions) Percentage Ownership Total Property, Plant and Equipment Accumulated Depreciation Net Property, Plant and Equipment McClain Plant (A) 77 % $ 257.1 $ 96.0 $ 161.1 Redbud Plant (A)(B) 51 % $ 531.8 $ 181.9 $ 349.9 (A) Construction work in progress was $0.1 million and $1.8 million for the McClain and Redbud Plants, respectively. (B) This amount includes a plant acquisition adjustment of $148.3 million and accumulated amortization of $67.3 million. The following tables present the Registrants' major classes of property, plant and equipment and related accumulated depreciation. December 31, 2021 (In millions) Total Property, Plant and Equipment Accumulated Depreciation Net Property, Plant and Equipment OG&E: Distribution assets $ 5,225.8 $ 1,477.5 $ 3,748.3 Electric generation assets (A) 5,037.9 1,839.0 3,198.9 Transmission assets (B) 3,038.2 627.0 2,411.2 Intangible plant 301.1 171.7 129.4 Other property and equipment 542.7 203.7 339.0 OG&E property, plant and equipment 14,145.7 4,318.9 9,826.8 Non-OG&E property, plant and equipment 6.1 — 6.1 Total OGE Energy property, plant and equipment $ 14,151.8 $ 4,318.9 $ 9,832.9 (A) This amount includes a plant acquisition adjustment of $148.3 million and accumulated amortization of $72.8 million. (B) This amount includes a plant acquisition adjustment of $3.3 million and accumulated amortization of $0.9 million. December 31, 2020 (In millions) Total Property, Plant and Equipment Accumulated Depreciation Net Property, Plant and Equipment OG&E: Distribution assets $ 4,809.9 $ 1,422.1 $ 3,387.8 Electric generation assets (A) 4,932.2 1,713.6 3,218.6 Transmission assets (B) 2,944.6 591.7 2,352.9 Intangible plant 254.1 153.9 100.2 Other property and equipment 495.3 186.3 309.0 OG&E property, plant and equipment 13,436.1 4,067.6 9,368.5 Non-OG&E property, plant and equipment 6.1 — 6.1 Total OGE Energy property, plant and equipment $ 13,442.2 $ 4,067.6 $ 9,374.6 (A) This amount includes a plant acquisition adjustment of $148.3 million and accumulated amortization of $67.3 million. (B) This amount includes a plant acquisition adjustment of $3.3 million and accumulated amortization of $0.9 million. OG&E's unamortized computer software costs, included in intangible plant above, were $103.7 million and $89.7 million at December 31, 2021 and 2020, respectively. OG&E's amortization expense for computer software costs was $18.1 million, $14.9 million and $11.0 million for the years ended December 31, 2021, 2020 and 2019, respectively. Depreciation and Amortization The provision for depreciation, which was 2.6 percent of the average depreciable utility plant for both 2021 and 2020, is calculated using the straight-line method over the estimated service life of the utility assets. Depreciation is provided at the unit level for production plant and at the account or sub-account level for all other plant and is based on the average life group method. In 2022, the provision for depreciation is projected to be 2.6 percent of the average depreciable utility plant. Amortization of intangible assets is calculated using the straight-line method. Of the remaining amortizable intangible plant balance at December 31, 2021, 99.1 percent will be amortized over 10.4 years with the remaining 0.9 percent of the intangible plant balance at December 31, 2021 being amortized over 23.7 years. Amortization of plant acquisition adjustments is provided on a straight-line basis over the estimated remaining service life of the acquired assets. Plant acquisition adjustments include $148.3 million for the Redbud Plant, which is being amortized over a 27 year life, and $3.3 million for certain transmission substation facilities in OG&E's service territory, which is being amortized over a 37 to 59 year period.
Inventory Disclosure [Text Block]	Fuel Inventories Fuel inventories for the generation of electricity consist of coal, natural gas and oil. OG&E uses the weighted-average cost method of accounting for inventory that is physically added to or withdrawn from storage or stockpiles. The amount of fuel inventory was $40.6 million and $36.5 million at December 31, 2021 and 2020, respectively.
Summary of Significant Accounting Policies [Text Block]	Accounting Records The accounting records of OG&E are maintained in accordance with the Uniform System of Accounts prescribed by the FERC and adopted by the OCC and the APSC. Additionally, OG&E, as a regulated utility, is subject to accounting principles for certain types of rate-regulated activities, which provide that certain incurred costs that would otherwise be charged to expense can be deferred as regulatory assets, based on the expected recovery from customers in future rates. Likewise, certain actual or anticipated credits that would otherwise reduce expense can be deferred as regulatory liabilities, based on the expected flowback to customers in future rates. Management's expected recovery of deferred costs and flowback of deferred credits generally results from specific decisions by regulators granting such ratemaking treatment. OG&E records certain incurred costs and obligations as regulatory assets or liabilities if, based on regulatory orders or other available evidence, it is probable that the costs or obligations will be included in amounts allowable for recovery or refund in future rates. The following table presents a summary of OG&E's regulatory assets and liabilities. December 31 (In millions) 2021 2020 REGULATORY ASSETS Current: Fuel clause under recoveries $ 151.9 $ — Oklahoma Energy Efficiency Rider under recoveries (A) 11.7 — SPP cost tracker under recovery (A) 9.3 7.0 Generation Capacity Replacement Rider under recovery (A) 1.0 4.4 Other (A) 8.7 8.4 Total current regulatory assets $ 182.6 $ 19.8 Non-current: Oklahoma Winter Storm Uri costs $ 747.9 $ — Oklahoma deferred storm expenses 172.8 158.8 Benefit obligations regulatory asset 109.2 164.9 Arkansas Winter Storm Uri costs 88.9 — Pension tracker 42.9 18.1 Sooner Dry Scrubbers 18.9 19.7 Arkansas deferred pension expenses 12.1 9.3 Unamortized loss on reacquired debt 8.9 9.7 COVID-19 impacts 8.2 6.4 Frontier Plant deferred expenses 6.7 6.4 Smart Grid 3.9 11.2 Other 10.4 11.1 Total non-current regulatory assets $ 1,230.8 $ 415.6 REGULATORY LIABILITIES Current: Fuel clause over recoveries $ — $ 28.6 Other (B) 2.5 6.5 Total current regulatory liabilities $ 2.5 $ 35.1 Non-current: Income taxes refundable to customers, net $ 930.7 $ 867.4 Accrued removal obligations, net 296.8 316.8 Other 3.6 4.7 Total non-current regulatory liabilities $ 1,231.1 $ 1,188.9 (A) Included in Other Current Assets in the balance sheets. (B) Included in Other Current Liabilities in the balance sheets. Fuel clause under and over recoveries are generated from OG&E's customers when OG&E's cost of fuel either exceeds or is less than the amount billed to its customers, respectively. OG&E's fuel recovery clauses are designed to smooth the impact of fuel price volatility on customers' bills. As a result, OG&E under recovers fuel costs in periods of rising fuel prices above the baseline charge for fuel and over recovers fuel costs when prices decline below the baseline charge for fuel. Provisions in the fuel clauses are intended to allow OG&E to amortize under and over recovery balances. OG&E recovers program costs related to the Energy Efficiency Program in Oklahoma through the Energy Efficiency Rider, which operates on a three-year program cycle. The previous program cycle, which ran through 2021, included recovery of (i) energy efficiency program costs, (ii) lost revenues associated with certain achieved energy efficiency and demand savings, (iii) performance-based incentives and (iv) costs associated with research and development investments. A new program cycle related to 2022 through 2024 programs was approved on February 1, 2022, as further discussed in Note 16. OG&E recovers certain SPP costs related to base plan charges from its customers and refunds certain SPP revenues received to its customers in Oklahoma through the SPP cost tracker and in Arkansas through the transmission cost recovery rider. OG&E recovers the Oklahoma jurisdictional portion of costs, including non-fuel operation and maintenance expenses, depreciation, taxes other than income taxes and a return on capital, for its investment in the River Valley plant and, beginning May 1, 2021, the Frontier plant, through the Generation Capacity Replacement Rider. The OCC also authorized OG&E to defer the same costs through April 30, 2021 related to its investment in the Frontier plant to a regulatory asset, and recovery of these costs will be considered in future rate proceedings. In February 2021, Winter Storm Uri resulted in record winter peak demand for electricity and extremely high natural gas and purchased power prices in OG&E's service territory. OG&E's natural gas costs for the month of February 2021 exceeded the total cost for all of 2020. The OCC allowed OG&E to create a regulatory asset for the Oklahoma portion of all deferred costs with an initial carrying charge based on the effective cost of the related debt financing for an amortization period to be determined at a later date. See Note 16 for further discussion of the Oklahoma securitization process related to this regulatory asset. The APSC allowed OG&E to create a regulatory asset for the Arkansas portion of all deferred costs with an initial carrying charge equal to the current customer deposit interest rate to be recovered over a period of 10 years beginning in May 2021. OG&E includes in expense any Oklahoma storm-related operation and maintenance expenses up to $2.7 million annually and defers to a regulatory asset any additional expenses incurred over $2.7 million. OG&E typically recovers the amounts deferred each year over a five-year period in accordance with historical practice. To mitigate customer impact, OG&E has agreed to recover the portion related to 2020 excess storm costs through the Storm Cost Recovery Rider over a ten-year period. The benefit obligations regulatory asset is comprised of expenses recorded which are probable of future recovery and that have not yet been recognized as components of net periodic benefit cost, including net loss and prior service cost. These expenses are recorded as a regulatory asset as OG&E historically has recovered and currently recovers pension and postretirement benefit plan expense in its electric rates. If, in the future, the regulatory bodies indicate a change in policy related to the recovery of pension and postretirement benefit plan expenses, this could cause the benefit obligations regulatory asset balance to be reclassified to accumulated other comprehensive income. The following table presents a summary of the components of the benefit obligations regulatory asset. December 31 (In millions) 2021 2020 Pension Plan and Restoration of Retirement Income Plan: Net loss $ 89.6 $ 147.3 Postretirement Benefit Plans: Net loss 23.2 26.2 Prior service cost (3.6) (8.6) Total $ 109.2 $ 164.9 OG&E recovers specific amounts of pension and postretirement medical costs in rates approved in its Oklahoma rate reviews. In accordance with approved orders, OG&E defers the difference between actual pension and postretirement medical expenses and the amount approved in its last Oklahoma rate review as a regulatory asset or regulatory liability. These amounts have been recorded in the Pension tracker regulatory asset in the table above. As approved by the OCC, OG&E deferred the non-fuel incremental operation and maintenance expenses, depreciation, debt cost associated with the capital investment and related ad valorem taxes for the Dry Scrubbers at Sooner Units 1 and 2 as a regulatory asset, and these costs are being recovered over 25 years. Arkansas includes a certain level of pension expense in base rates. When the Pension Plan experiences a settlement, which represents an acceleration of future pension costs, OG&E defers to a regulatory asset the Arkansas jurisdictional portion of each settlement, which historically has been recovered from customers over the average life of the remaining plan participants. A portion of these settlements is being recovered in current rates, and recovery of additional amounts will be requested as additional settlements occur. For additional information related to settlements, see Note 13. Unamortized loss on reacquired debt is comprised of unamortized debt issuance costs related to the early retirement of OG&E's long-term debt. These amounts are recorded in interest expense and are being amortized over the term of the long-term debt which replaced the previous long-term debt. The unamortized loss on reacquired debt is recovered as a part of OG&E's cost of capital. In response to the COVID-19 pandemic, the OCC and APSC issued orders allowing OG&E to defer certain expenses related to its COVID-19 response, such as incremental expenses that are related to the suspension of or delay in disconnection of service and additional expenses associated with ensuring the continuity of utility service. OG&E deferred to a regulatory asset the incremental and stranded costs that were accumulated during Smart Grid deployment, including (i) costs for web portal access, (ii) costs for education and home energy reports and (iii) stranded costs associated with OG&E's analog electric meters, which have been replaced by smart meters. As approved by the OCC and APSC, these costs are being recovered over a six-year period ending in 2022 in Oklahoma and 2023 in Arkansas. Income taxes refundable to customers, net, represents the reduction in accumulated deferred income taxes resulting from the reduction in the federal income tax rate as part of the Tax Cuts and Jobs Act of 2017 and other state tax rate changes and includes income taxes recoverable from customers that represent income tax benefits previously used to reduce OG&E's revenues (treated as regulatory assets). These liabilities will be returned to customers in varying amounts over approximately 80 years, and the assets will be amortized over the estimated remaining life of the assets to which they relate, as the temporary differences that generated the income tax benefits turn around. Accrued removal obligations, net represents asset retirement costs previously recovered from ratepayers for other than legal obligations.
Reclassifications [Text Block]	Reclassifications Certain prior year amounts have been reclassified to conform to the current year presentation. OGE Energy changed the classification of certain investments in its 2020 consolidated balance sheet to conform with current year presentation. The prior year reclassification of $23.1 million from Investment in Unconsolidated Affiliates to Other Property and Investments did not impact previously reported current or total assets.
Investment	Investment in Equity Securities of Energy Transfer OGE Energy accounts for its investment in Energy Transfer's equity securities as an equity investment with a readily determinable fair value under ASC 321, "Investments – Equity Securities." OGE Energy presents the Energy Transfer equity securities at estimated fair value in its balance sheet. OGE Energy presents realized and unrealized gains and losses of the equity securities, as well as dividend income from the investment, within the Other Income (Expense) section in its statement of income, as appropriate. During the period between December 2, 2021 and December 31, 2021, OGE Energy recognized an unrealized loss of $8.6 million related to its investment in Energy Transfer's equity securities. On January 25, 2022, Energy Transfer announced a 15 percent increase in its quarterly cash distribution, resulting in a distribution of $0.175 per unit on its outstanding common units that was paid on February 18, 2022.

Accounting Pronouncements

Accounting Pronouncements	12 Months Ended
	Dec. 31, 2021
Accounting Pronouncement [Abstract]
New Accounting Pronouncements and Changes in Accounting Principles [Text Block]	Accounting PronouncementsThe Registrants believe that recently adopted and recently issued accounting standards that are not yet effective do not appear to have a material impact on the Registrants' financial position, results of operations or cash flows upon adoption.

Revenue from Contracts with Cus

Revenue from Contracts with Customers (Notes)	12 Months Ended
	Dec. 31, 2021
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer [Text Block]	Revenue Recognition The following table presents OG&E's revenues from contracts with customers disaggregated by customer classification. OG&E's operating revenues disaggregated by customer classification can be found in "OG&E (Electric Utility) Results of Operations" within "Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations." Year Ended December 31, (In millions) 2021 2020 2019 Residential $ 1,309.1 $ 842.7 $ 865.8 Commercial 749.2 465.6 486.6 Industrial 323.0 192.6 217.8 Oilfield 312.8 169.2 200.4 Public authorities and street light 284.4 172.3 190.3 System sales revenues 2,978.5 1,842.4 1,960.9 Provision for rate refund — 3.8 (0.9) Integrated market 468.9 49.6 38.4 Transmission 140.2 143.3 148.0 Other 1.1 30.7 29.1 Revenues from contracts with customers (A) $ 3,588.7 $ 2,069.8 $ 2,175.5 (A) In February 2021, Winter Storm Uri resulted in record winter peak demand for electricity and extremely high natural gas and purchased power prices in OG&E's service territory. Operating revenues significantly increased due to increased fuel, purchased power and direct transmission expenses, which are generally recoverable from customers, as a result of Winter Storm Uri. For further discussion, see Note 16 and "Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations."

Leases, Codification Topic 842

Leases, Codification Topic 842	12 Months Ended
	Dec. 31, 2021
Leases [Abstract]
Lessee, Operating Leases	Leases Based on their evaluation of all contracts under ASC 842, as described in Note 1, the Registrants concluded they have operating lease obligations as described below. Operating Leases OG&E Railcar Lease Agreement Effective February 1, 2019, OG&E renewed a railcar lease agreement for 780 rotary gondola railcars to transport coal from Wyoming to OG&E's coal-fired generation units. Rental payments are charged to fuel expense and are recoverable through OG&E's fuel adjustment clauses. On February 1, 2024, OG&E has the option to either purchase the railcars at a stipulated fair market value or renew the lease. If OG&E chooses not to purchase the railcars or renew the lease agreement and the actual fair value of the railcars is less than the stipulated fair market value, OG&E would be responsible for the difference in those values up to a maximum of $6.8 million. OG&E Wind Farm Land Lease Agreements OG&E has operating leases related to land for OG&E's Centennial, OU Spirit and Crossroads wind farms with terms of 25 to 30 years. The Centennial lease has rent escalations which increase annually based on the Consumer Price Index. While lease liabilities are not remeasured as a result of changes to the Consumer Price Index, changes to the Consumer Price Index are treated as variable lease payments and recognized in the period in which the obligation for those payments was incurred. The OU Spirit and Crossroads leases have rent escalations which increase after five and 10 years. Although the leases are cancellable, OG&E is required to make annual lease payments as long as the wind turbines are located on the land. OG&E does not expect to terminate the leases until the wind turbines reach the end of their useful life. Financial Statement Information and Maturity Analysis of Lease Liabilities The following tables present amounts recognized for operating leases in the Registrants' income statements, cash flow statements and balance sheets and supplemental information related to those amounts recognized. OGE Energy OG&E Year Ended December 31, Year Ended December 31, (In millions) 2021 2020 2019 2021 2020 2019 Operating lease cost $ 6.3 $ 6.4 $ 6.0 $ 5.7 $ 5.5 $ 5.1 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows for operating leases $ 6.3 $ 6.4 $ 5.6 $ 5.7 $ 5.5 $ 4.8 Right-of-use assets obtained in exchange for new operating lease liabilities $ — $ 1.4 $ 10.7 $ — $ 1.4 $ 10.7 OGE Energy OG&E (Dollars in millions) December 31, 2021 December 31, 2020 December 31, 2021 December 31, 2020 Right-of-use assets at period end (A) $ 33.0 $ 37.6 $ 33.0 $ 37.0 Operating lease liabilities at period end (B) $ 37.6 $ 42.3 $ 37.6 $ 41.7 Operating lease weighted-average remaining lease term (in years) 12.2 12.5 12.2 12.7 Operating lease weighted-average discount rate 3.9 % 3.9 % 3.9 % 3.9 % (A) Included in Property, Plant and Equipment in the Registrants' balance sheets. (B) Included in Other Deferred Credits and Other Liabilities in the Registrants' balance sheets. The following table presents a maturity analysis of the Registrants' operating lease liabilities. Future minimum operating lease payments as of December 31: OGE Energy OG&E (In millions) 2022 $ 5.7 $ 5.7 2023 5.1 5.1 2024 3.1 3.1 2025 3.0 3.0 2026 3.0 3.0 Thereafter 28.7 28.7 Total future minimum lease payments 48.6 48.6 Less: Imputed interest 11.0 11.0 Present value of net minimum lease payments $ 37.6 $ 37.6

Investment in Unconsolidated Af

Investment in Unconsolidated Affiliate	12 Months Ended
	Dec. 31, 2021
Schedule of Equity Method Investments [Line Items]
Equity Method Investments and Joint Ventures Disclosure [Text Block]	Investment in Unconsolidated Affiliates On December 2, 2021, Energy Transfer completed its acquisition of Enable, and all of the 110,982,805 common units of Enable owned by OGE Energy were exchanged for 95,389,721 common units of Energy Transfer. As part of the transaction, Energy Transfer also acquired the general partner interests of Enable from OGE Energy and CenterPoint for cash consideration. Further discussion of the transaction can be found in Note 1. The below discussion relates to OGE Energy's equity method investment in Enable prior to December 2, 2021. In 2013, OGE Energy, CenterPoint and another party formed Enable as a private limited partnership, and OGE Energy and the other party indirectly contributed 100 percent of the equity interests in Enogex LLC to Enable. OGE Energy determined that its contribution of Enogex LLC to Enable met the requirements of being in substance real estate and recorded the contribution at historical cost. The formation of Enable was considered a business combination, and CenterPoint was the acquirer of Enogex Holdings for accounting purposes. Under this method, the fair value of the consideration paid by CenterPoint for Enogex Holdings was allocated to the assets acquired and liabilities assumed based on their fair value. Enogex Holdings' assets, liabilities and equity were accordingly adjusted to estimated fair value, resulting in an increase to Enable's equity of $2.2 billion. Since the contribution of Enogex LLC to Enable was recorded at historical cost, the effects of the amortization and depreciation expense associated with the fair value adjustments on Enable's results of operations were eliminated in OGE Energy's recording of its equity in earnings of Enable through the closing date of December 2, 2021. As prior real estate sales accounting guidance was superseded by ASU 2017-05, "Other Income - Gains and Losses from the Derecognition of Nonfinancial Assets," prior to December 2, 2021, OGE Energy recognized gains or losses on sales or dilution events in its investment in Enable within OGE Energy's earnings, net of proportional basis difference recognition. OGE Energy recorded equity in earnings of unconsolidated affiliates of $169.8 million for the period of January 1, 2021 through December 2, 2021 compared to equity in losses of unconsolidated affiliates of $668.0 million for the year ended December 31, 2020 and equity in earnings of unconsolidated affiliates of $113.9 million for the year ended December 31, 2019. Equity in earnings (losses) of unconsolidated affiliates includes OGE Energy's share of Enable's earnings adjusted for the amortization of the basis difference of OGE Energy's original investment in Enogex LLC and its previous underlying equity in the net assets of Enable, as well as any impairment OGE Energy recorded on its investment in Enable. Equity in earnings (losses) of unconsolidated affiliates was also adjusted for the elimination of the Enogex Holdings fair value adjustments, as described above. These amortizations may also include gain or loss on dilution, net of proportional basis difference recognition. The following tables present summarized unaudited financial information for 100 percent of Enable as of December 2, 2021 and December 31, 2020 and for the period of January 1, 2021 through December 2, 2021 and the years ended December 31, 2020 and 2019. Balance Sheet December 2, 2021 December 31, 2020 (In millions) Current assets $ 594 $ 381 Non-current assets $ 11,227 $ 11,348 Current liabilities $ 1,254 $ 582 Non-current liabilities $ 3,281 $ 4,052 Period of January 1, 2021 through December 2, 2021 Year Ended Income Statement December 31, 2020 December 31, 2019 (In millions) Total revenues $ 3,466 $ 2,463 $ 2,960 Cost of natural gas and NGLs (excluding depreciation and amortization) $ 1,959 $ 965 $ 1,279 Operating income $ 634 $ 465 $ 569 Net income $ 461 $ 52 $ 360 The following table presents a reconciliation of OGE Energy's equity in earnings (losses) of unconsolidated affiliates for the period of January 1, 2021 through December 2, 2021 and the years ended December 31, 2020 and 2019. For further discussion of Enable's net income, see "Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations - Results of Operations - OGE Holdings (Natural Gas Midstream Operations)." Period of January 1, 2021 through December 2, 2021 Year Ended (In millions) December 31, 2020 December 31, 2019 Enable net income $ 461.0 $ 52.0 $ 360.0 Differences due to timing of OGE Energy and Enable accounting close 9.0 — — Enable net income used to calculate OGE Energy's equity in earnings $ 470.0 $ 52.0 $ 360.0 OGE Energy's percent ownership at period end 25.5 % 25.5 % 25.5 % OGE Energy's portion of Enable net income $ 119.8 $ 13.2 $ 91.8 Amortization of basis difference and dilution recognition (A) 50.0 98.8 22.1 Impairment of OGE Energy's equity method investment in Enable (B) — (780.0) — Equity in earnings (losses) of unconsolidated affiliates (C) $ 169.8 $ (668.0) $ 113.9 (A) Includes loss on dilution, net of proportional basis difference recognition. (B) Effective March 31, 2020, OGE Energy estimated the fair value of its investment in Enable was below the book value and concluded the decline in value was not temporary due to the severity of the decline and recent rapid deterioration, as well as the near term future outlook, of the midstream oil and gas industry. Accordingly, OGE Energy recorded a $780.0 million impairment on its investment in Enable in 2020. Further information concerning the fair value method used to measure the impairment on OGE Energy's investment in Enable can be found in Note 7. (C) For the year ended December 31, 2020, Enable recorded a $225.0 million impairment on its SESH equity method investment. Enable estimated the fair value of this equity method investment was below the carrying value at September 30, 2020 and concluded the decline in value was other than temporary due to the expiration of a transportation contract and the current status of renewal negotiations. The impairment ran through OGE Energy's portion of Enable net income and was offset by basis differences that flow through the amortization of basis difference and dilution recognition line item above. Distributions received from Enable were $73.4 million, $91.7 million and $144.0 million during the years ended December 31, 2021, 2020 and 2019, respectively.

Related Party Disclosures

Related Party Disclosures	12 Months Ended
	Dec. 31, 2021
Related Party Transactions [Abstract]
Related Party Transactions Disclosure	Related Party Transactions OGE Energy charges operating costs to OG&E, and prior to December 2, 2021, charged operating costs to Enable, based on several factors. Operating costs directly related to OG&E and/or Enable are assigned as such. Operating costs incurred for the benefit of OG&E are allocated either as overhead based primarily on labor costs or using the "Distrigas" method, which is a three-factor formula that uses an equal weighting of payroll, net operating revenues and gross property, plant and equipment. OGE Energy and OG&E OGE Energy charged operating costs to OG&E of $139.3 million, $140.6 million and $149.8 million during the years ended December 31, 2021, 2020 and 2019, respectively. In 2021 and 2020, OG&E declared dividends to OGE Energy of $265.0 million and $325.0 million, respectively. In 2019, no dividends were declared from OG&E to OGE Energy. OGE Energy and Enable Prior to December 2, 2021, OGE Energy and Enable were parties to several agreements whereby OGE Energy provided specified support services to Enable, such as certain information technology, payroll and benefits administration. Under these agreements, OGE Energy charged operating costs to Enable of $0.3 million, $0.4 million and $0.5 million for the period of January 1, 2021 through December 2, 2021, year ended December 31, 2020 and year ended December 31, 2019, respectively. OGE Energy provided retirement benefits and retiree health care benefits to 63 employees previously seconded to Enable. OGE Energy billed Enable for reimbursement of $12.2 million, $17.3 million and $23.2 million in 2021, 2020 and 2019, respectively, under the former seconding agreement for employment costs. As of a result of the merger between Enable and Energy Transfer, the seconding agreement was terminated, and those employees are no longer employed by OGE Energy. If lump sum payments were made to those employees previously seconded to Enable, OGE Energy would recognize a settlement or curtailment of the pension/retiree health care charges, which would increase expense at OGE Energy by $19.4 million. Settlement and curtailment charges associated with the employees previously seconded to Enable are not reimbursable to OGE Energy. OGE Energy had accounts receivable from Enable for amounts billed for support services, including the cost of seconded employees, of $0.3 million and $2.0 million as of December 31, 2021 and 2020, respectively, which are included in Accounts Receivable in OGE Energy's balance sheets. OG&E and Enable Enable provided gas transportation services to OG&E pursuant to agreements, which expire in May 2024 and December 2038, that granted Enable the responsibility of delivering natural gas to OG&E's generating facilities and performing an imbalance service. With this imbalance service, in accordance with the cash-out provision of the contract, OG&E purchased gas from Enable when Enable's deliveries exceeded OG&E's pipeline receipts. Enable purchased gas from OG&E when OG&E's pipeline receipts exceeded Enable's deliveries. Further, an additional gas transportation services contract with Enable became effective in December 2018 related to the project to convert Muskogee Units 4 and 5 from coal to natural gas. Upon the closing of the merger between Enable and Energy Transfer, these contracts were assumed by Energy Transfer. The following table presents summarized related party transactions between OG&E and Enable during the period of January 1, 2021 through December 2, 2021 and the years ended December 31, 2020 and 2019. Period of January 1, 2021 through December 2, 2021 Year Ended (In millions) December 31, 2020 December 31, 2019 Operating revenues: Electricity to power electric compression assets $ 13.3 $ 15.1 $ 15.9 Fuel, purchased power and direct transmission expense: Natural gas transportation services $ 32.7 $ 32.8 $ 41.2 Natural gas purchases (sales) $ (33.5) $ 2.7 $ (6.0)

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The classification of the Registrants' fair value measurements requires judgment regarding the degree to which market data is observable or corroborated by observable market data. GAAP establishes a fair value hierarchy that prioritizes the inputs used to measure fair value based on observable and unobservable data. The hierarchy categorizes the inputs into three levels, with the highest priority given to quoted prices in active markets for identical unrestricted assets or liabilities (Level 1) and the lowest priority given to unobservable inputs (Level 3). Financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The three levels defined in the fair value hierarchy are as follows: Level 1 inputs are quoted prices in active markets for identical unrestricted assets or liabilities that are accessible at the measurement date. Level 2 inputs are inputs other than quoted prices in active markets included within Level 1 that are either directly or indirectly observable at the reporting date for the asset or liability for substantially the full term of the asset or liability. Level 2 inputs include quoted prices for similar assets or liabilities in active markets and quoted prices for identical or similar assets or liabilities in markets that are not active. Level 3 inputs are prices or valuation techniques for the asset or liability that require inputs that are both significant to the fair value measurement and unobservable (i.e., supported by little or no market activity). Unobservable inputs reflect the reporting entity's own assumptions about the assumptions that market participants would use in pricing the asset or liability (including assumptions about risk). OG&E had no financial instruments measured at fair value on a recurring basis at December 31, 2021 and 2020. The following table presents OGE Energy's financial instrument measured at fair value on a recurring basis and the carrying amount and fair value of the Registrants' financial instruments at December 31, 2021 and 2020, as well as the classification level within the fair value hierarchy. 2021 2020 December 31 (In millions) Carrying Amount Fair Carrying Amount Fair Classification Financial instrument measured at fair value on a recurring basis: OGE Energy investment in Energy Transfer's equity securities $ 785.1 $ 785.1 (A) (A) Level 1 Financial instruments for which fair value is only disclosed: Long-term Debt (including Long-term Debt due within one year): OGE Energy Senior Notes $ 499.9 $ 497.8 $ — $ — Level 2 OG&E Senior Notes $ 3,851.8 $ 4,460.2 $ 3,349.6 $ 4,182.1 Level 2 OG&E Industrial Authority Bonds $ 135.4 $ 135.4 $ 135.4 $ 135.4 Level 2 Tinker Debt $ 9.3 $ 10.0 $ 9.4 $ 10.7 Level 3 (A) OGE Energy's ownership of Energy Transfer securities was effective as of December 2, 2021; therefore, the investment in Energy Transfer's equity securities was not held at December 31, 2020. Nonrecurring Fair Value Measurements As further discussed in Note 5, OGE Energy recorded an impairment on its investment in Enable in March 2020. The nonrecurring fair value measurement consisted of calculating a 20-trading day volume weighted average price for Enable's common units through March 31, 2020. This method of valuation was determined to be representative of the fair value of Enable's common units as it incorporated market prices during the period and reduced the impact of volatility that a single day could represent. OGE Energy concluded that this valuation method resulted in a Level 3 nonrecurring fair value measurement.

Stock Based Compensation

Stock Based Compensation	12 Months Ended
	Dec. 31, 2021
Stock-Based Compensation [Abstract]
Disclosure of Compensation Related Costs, Share-based Payments [Text Block]	Stock-Based Compensation In 2013, OGE Energy adopted, and its shareholders approved, the Stock Incentive Plan. Under the Stock Incentive Plan, restricted stock, restricted stock units, stock options, stock appreciation rights and performance units may be granted to officers, directors and other key employees of OGE Energy and its subsidiaries, including OG&E. OGE Energy has authorized the issuance of up to 7,400,000 shares under the Stock Incentive Plan. The following table presents the Registrants' pre-tax compensation expense and related income tax benefit for the years ended December 31, 2021, 2020 and 2019 related to performance units and restricted stock units for the Registrants' employees. OGE Energy OG&E Year Ended December 31 (In millions) 2021 2020 2019 2021 2020 2019 Performance units: Total shareholder return $ 7.5 $ 7.9 $ 8.7 $ 1.8 $ 2.3 $ 3.0 Earnings per share — 1.0 4.3 — 0.3 1.5 Total performance units 7.5 8.9 13.0 1.8 2.6 4.5 Restricted stock units 2.3 0.9 0.9 0.4 0.4 0.4 Total compensation expense $ 9.8 $ 9.8 $ 13.9 $ 2.2 $ 3.0 $ 4.9 Income tax benefit $ 2.5 $ 2.5 $ 3.6 $ 0.6 $ 0.8 $ 1.3 During the year ended December 31, 2020, OGE Energy purchased 405,000 shares of its common stock, and 154,523 and 247,252 of these shares were used during December 31, 2021 and 2020, respectively, to satisfy payouts of earned performance units and restricted stock unit grants to the Registrants' employees pursuant to OGE Energy's Stock Incentive Plan. The shares were purchased at an average cost of $38.04 and $33.14 per share on the open market during March 2020 and August 2020, respectively. OGE Energy records treasury stock purchases at cost. Treasury stock is presented as a reduction of stockholders' equity in OGE Energy's balance sheets. During the year ended December 31, 2020, there was an immaterial number of shares of new common stock issued pursuant to OGE Energy's Stock Incentive Plan to satisfy restricted stock unit grants to employees. During the year ended December 31, 2019, OGE Energy issued 443,900 shares of new common stock to satisfy payouts of earned performance units and restricted stock unit grants to the Registrants' employees. Performance Units Under the Stock Incentive Plan, OGE Energy has issued performance units which represent the value of one share of OGE Energy's common stock. The performance units provide for accelerated vesting if there is a change in control (as defined in the Stock Incentive Plan). Each performance unit is subject to forfeiture if the recipient terminates employment with OGE Energy or a subsidiary prior to the end of the primarily three-year award cycle for any reason other than death, disability or retirement. In the event of death, disability or retirement, a participant will receive a prorated payment based on such participant's number of full months of service during the award cycle, further adjusted based on the achievement of the performance goals during the award cycle. The Registrants estimate expected forfeitures in accounting for performance unit compensation expense. The performance units granted based on total shareholder return are contingently awarded and will be payable in shares of OGE Energy's common stock subject to the condition that the number of performance units, if any, earned by the employees upon the expiration of a primarily three-year award cycle (i.e., three-year cliff vesting period) is dependent on OGE Energy's total shareholder return ranking relative to a peer group of companies. The performance units granted based on earnings per share were contingently awarded and will be payable in shares of OGE Energy's common stock based on OGE Energy's earnings per share growth over a primarily three-year award cycle (i.e., three-year cliff vesting period) compared to a target set at the time of the grant by the Compensation Committee of OGE Energy's Board of Directors. All of these performance units are classified as equity in the balance sheets. If there is no or only a partial payout for the performance units at the end of the award cycle, the unearned performance units are cancelled. Payout requires approval of the Compensation Committee of OGE Energy's Board of Directors. Payouts, if any, are all made in common stock and are considered made when the payout is approved by the Compensation Committee. Performance Units – Total Shareholder Return The fair value of the performance units based on total shareholder return was estimated on the grant date using a lattice-based valuation model that factors in information, including the expected dividend yield, expected price volatility, risk-free interest rate and the probable outcome of the market condition, over the expected life of the performance units. Compensation expense for the performance units is a fixed amount determined at the grant date fair value and is recognized over the primarily three-year award cycle regardless of whether performance units are awarded at the end of the award cycle. Dividends are accrued on a quarterly basis pending achievement of payout criteria and are included in the fair value calculations. Expected price volatility is based on the historical volatility of OGE Energy's common stock for the past three years and is simulated using the Geometric Brownian Motion process. The risk-free interest rate for the performance unit grants is based on the three-year U.S. Treasury yield curve in effect at the time of the grant. The expected life of the units is based on the non-vested period since inception of the award cycle. There are no post-vesting restrictions related to OGE Energy's performance units based on total shareholder return. The following table presents the number of performance units granted based on total shareholder return and the assumptions used to calculate the grant date fair value of the performance units based on total shareholder return. OGE Energy OG&E 2021 2020 2019 2021 2020 2019 Number of units granted 249,909 201,552 208,647 68,720 67,975 68,396 Fair value of units granted $ 38.14 $ 38.03 $ 47.00 $ 38.14 $ 38.03 $ 47.00 Expected dividend yield 4.7 % 3.5 % 4.0 % 4.7 % 3.5 % 4.0 % Expected price volatility 29.0 % 15.0 % 17.0 % 29.0 % 15.0 % 17.0 % Risk-free interest rate 0.22 % 1.17 % 2.47 % 0.22 % 1.17 % 2.47 % Expected life of units (in years) 2.84 2.85 2.86 2.85 2.85 2.86 Performance Units – Earnings Per Share In 2019, the Compensation Committee of OGE Energy's Board of Directors voted to grant restricted stock units in lieu of performance units based on earnings per share. The last outstanding grant of performance units based on earnings per share paid out during 2021. Prior to payout, OGE Energy reassessed at each reporting date whether achievement of the performance condition was probable and accrued compensation expense if and when achievement of the performance condition was probable. As a result, the compensation expense recognized for these performance units varied from period to period. There are no post-vesting restrictions related to OGE Energy's performance units based on earnings per share. Restricted Stock Units Under the Stock Incentive Plan, OGE Energy has issued restricted stock units to certain existing non-officer employees as well as other executives upon hire to attract and retain individuals to be competitive in the marketplace, and as of the 2019 grant cycle, restricted stock units are granted in lieu of performance units based on earnings per share. The restricted stock units vest primarily in a three-year award cycle (i.e., three-year cliff vesting period). Prior to vesting, each restricted stock unit is subject to forfeiture if the recipient ceases to render substantial services to OGE Energy or a subsidiary. These restricted stock units may not be sold, assigned, transferred or pledged and are subject to a risk of forfeiture. The fair value of the restricted stock units was based on the closing market price of OGE Energy's common stock on the grant date. Compensation expense for the restricted stock units is a fixed amount determined at the grant date fair value and is recognized as services are rendered by employees over a primarily three-year vesting period. Also, for those restricted stock units that vest in one-third annual increments over a three-year cycle, OGE Energy treats its restricted stock units as multiple separate awards by recording compensation expense separately for each tranche whereby a substantial portion of the expense is recognized in the earlier years in the requisite service period. Dividends will only be paid on restricted stock unit awards that vest; therefore, only the present value of dividends expected to vest are included in the fair value calculations. The expected life of the restricted stock units is based on the non-vested period since inception of the primarily three-year award cycle. There are no post-vesting restrictions related to OGE Energy's restricted stock units. The following table presents the number of restricted stock units granted and the grant date fair value. OGE Energy OG&E 2021 2020 2019 2021 2020 2019 Restricted stock units granted 89,197 67,193 75,929 22,911 22,665 26,141 Fair value of restricted stock units granted $ 31.11 $ 43.69 $ 41.71 $ 30.91 $ 43.69 $ 41.63 Performance Units and Restricted Stock Units Activity The following tables present a summary of the activity for the Registrants' performance units and restricted stock units for the year ended December 31, 2021. The table designated as "OGE Energy" below includes the OG&E standalone activity, as OGE Energy represents consolidated results. OGE Energy Performance Units Restricted Total Shareholder Return Earnings Per Share (Dollars in millions) Number Aggregate Intrinsic Value Number Aggregate Intrinsic Value Number Aggregate Intrinsic Value Units/shares outstanding at 12/31/20 612,262 79,002 124,919 Granted 249,909 (A) — 89,197 Converted (236,990) (B) $ 5.4 (79,002) (B) $ 2.7 — Vested N/A N/A (53,274) $ 2.2 Forfeited (43,929) — (27,171) Units/shares outstanding at 12/31/21 581,252 $ 17.5 — $ — 133,671 $ 5.1 Units/shares fully vested at 12/31/21 172,748 $ — — $ — 47,907 $ 2.0 OG&E Performance Units Restricted Total Shareholder Return Earnings Per Share (Dollars in millions) Number Aggregate Intrinsic Value Number Aggregate Intrinsic Value Number Aggregate Intrinsic Value Units/shares outstanding at 12/31/20 182,363 25,235 34,130 Granted 68,720 (A) — 22,911 Converted (75,693) (B) $ 1.7 (25,235) (B) $ 0.8 — Vested N/A N/A (12,461) $ 0.6 Forfeited (14,132) — (8,986) Employee migration 52 (C) — (C) 19 (C) Units/shares outstanding at 12/31/21 161,310 $ 4.8 — $ — 35,613 $ 1.4 Units/shares fully vested at 12/31/21 48,195 $ — — $ — 11,241 $ 0.5 (A) For performance units, this represents the target number of performance units granted. Actual number of performance units earned, if any, is dependent upon performance and may range from zero percent to 200 percent of the target. (B) These amounts represent performance units that vested at December 31, 2020 which were settled in February 2021. (C) Due to certain employees transferring between OG&E and OGE Energy. The following tables present a summary of the activity for the Registrants' non-vested performance units and restricted stock units for the year ended December 31, 2021. The table designated as "OGE Energy" below includes the OG&E standalone activity, as OGE Energy represents consolidated results. OGE Energy Performance Units - Restricted Total Shareholder Return Number Weighted-Average Number Weighted-Average Units/shares non-vested at 12/31/20 375,272 $ 42.51 124,919 $ 42.69 Granted 249,909 (A) $ 38.14 89,197 $ 31.11 Vested (172,748) $ 47.00 (53,274) $ 41.59 Forfeited (43,929) $ 41.02 (27,171) $ 42.37 Units/shares non-vested at 12/31/21 408,504 $ 38.05 133,671 $ 35.64 OG&E Performance Units - Restricted Total Shareholder Return Number Weighted-Average Number Weighted-Average Units/shares non-vested at 12/31/20 106,670 $ 42.49 34,130 $ 42.67 Granted 68,720 (A) $ 38.14 22,911 $ 30.91 Vested (48,195) $ 47.00 (12,461) $ 45.67 Forfeited (14,132) $ 41.12 (8,986) $ 42.51 Employee migration 52 (B) $ 41.01 19 (B) $ 37.71 Units/shares non-vested at 12/31/21 113,115 $ 38.10 35,613 $ 35.52 (A) For performance units, this represents the target number of performance units granted. Actual number of performance units earned, if any, is dependent upon performance and may range from zero percent to 200 percent of the target. (B) Due to certain employees transferring between OG&E and OGE Energy. Fair Value of Vested Performance Units and Restricted Stock Units The following table presents a summary of the Registrants' fair value for vested performance units and restricted stock units. OGE Energy OG&E Year Ended December 31 (In millions) 2021 2020 2019 2021 2020 2019 Performance units: Total shareholder return $ 8.1 $ 8.7 $ 9.3 $ 2.3 $ 2.8 $ 3.2 Earnings per share $ — $ 2.5 $ 5.2 $ — $ 0.8 $ 0.9 Restricted stock units $ 2.2 $ 0.1 $ 0.1 $ 0.5 $ 0.1 $ — Unrecognized Compensation Cost The following table presents a summary of the Registrants' unrecognized compensation cost for non-vested performance units and restricted stock units and the weighted-average periods over which the compensation cost is expected to be recognized. OGE Energy OG&E December 31, 2021 Unrecognized Compensation Cost (In millions) Weighted Average to be Recognized (In years) Unrecognized Compensation Cost (In millions) Weighted Average to be Recognized (In years) Performance units - total shareholder return $ 7.5 1.71 $ 2.0 1.72 Restricted stock units 3.5 1.48 0.8 1.39 Total unrecognized compensation cost $ 11.0 $ 2.8

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2021
Income Taxes [Abstract]
Income Tax Disclosure [Text Block]	Income Taxes Income Tax Expense (Benefit) The following table presents the components of income tax expense (benefit). OGE Energy OG&E Year Ended December 31 (In millions) 2021 2020 2019 2021 2020 2019 Provision (benefit) for current income taxes: Federal $ 16.4 $ 8.4 $ (6.4) $ (9.0) $ (3.8) $ (7.9) State 1.7 0.5 5.1 9.0 (0.6) 4.1 Total provision (benefit) for current income taxes 18.1 8.9 (1.3) — (4.4) (3.8) Provision (benefit) for deferred income taxes, net: Federal 133.1 (105.2) 48.5 58.3 45.7 37.7 State (10.0) (31.1) (17.4) (16.5) (6.6) (13.8) Total provision (benefit) for deferred income taxes, net 123.1 (136.3) 31.1 41.8 39.1 23.9 Total income tax expense (benefit) $ 141.2 $ (127.4) $ 29.8 $ 41.8 $ 34.7 $ 20.1 OGE Energy files consolidated income tax returns in the U.S. federal jurisdiction and various state jurisdictions. OG&E is a part of the consolidated income tax return of OGE Energy. With few exceptions, the Registrants are no longer subject to U.S. federal tax or state and local examinations by tax authorities for years prior to 2018. Income taxes are generally allocated to each company in the affiliated group, including OG&E, based on its stand-alone taxable income or loss. Federal investment tax credits previously claimed on electric utility property have been deferred and will be amortized to income over the life of the related property. Additionally, OG&E earns federal tax credits associated with production from its wind facilities. Oklahoma production and investment state tax credits are also earned on investments in electric and solar generating facilities which further reduce OG&E's effective tax rate. The following table presents a reconciliation of the statutory tax rates to the effective income tax rate. OGE Energy OG&E Year Ended December 31 2021 2020 2019 2021 2020 2019 Statutory federal tax rate 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % State income taxes, net of federal income tax 0.9 (1.4) (1.2) (1.4) (1.6) (1.8) Stock-based compensation 0.1 (0.3) (1.2) — — — Executive compensation limitation 0.1 0.2 0.2 — — — Amortization of net unfunded deferred taxes (2.1) (4.4) (4.5) (4.6) (4.8) (5.6) Federal renewable energy credit (A) (2.0) (5.0) (6.0) (4.4) (5.4) (7.6) Remeasurement of state deferred taxes due to Energy Transfer merger (B) (1.1) — — — — — Remeasurement of state deferred tax liabilities (0.6) 0.9 (0.8) — — — 401(k) dividends (0.2) (0.4) (0.4) — — — Impairment of OGE Energy's investment in Enable (C) — 31.6 — — — — Other — 0.1 (0.7) (0.2) 0.1 (0.6) Effective income tax rate 16.1 % 42.3 % 6.4 % 10.4 % 9.3 % 5.4 % (A) Represents credits primarily associated with the production from OG&E's wind farms. (B) In connection with the Enable and Energy Transfer merger, the state income tax rates are expected to decrease, as Energy Transfer operates in significantly more states with generally lower tax rates than the historic Enable operating area. (C) As further discussed in Note 5, OGE Energy recorded a $780.0 million impairment on its investment in Enable in March 2020, which resulted in a tax benefit being recorded that caused a significant variance to the effective tax rate. This variance has been presented in the table as a single line item in order to facilitate comparability of other components of the effective tax rate. The deferred tax provisions are recognized as costs in the ratemaking process by the commissions having jurisdiction over the rates charged by OG&E. The following table presents the components of Deferred Income Taxes at December 31, 2021 and 2020. OGE Energy OG&E December 31 (In millions) 2021 2020 2021 2020 Deferred income tax liabilities, net: Accelerated depreciation and other property related differences $ 1,677.3 $ 1,721.2 $ 1,677.3 $ 1,721.2 Investment in Enable — 302.6 — — Investment in Energy Transfer's equity securities 363.5 — — — Regulatory assets 52.1 52.3 52.1 52.3 Pension Plan 10.7 3.9 32.0 27.4 Other 7.4 (1.4) (4.7) (6.5) Derivative instruments 2.2 1.7 — — Bond redemption-unamortized costs 1.8 2.0 1.8 2.0 Income taxes recoverable from customers, net (225.8) (221.8) (225.8) (221.8) State tax credits (221.2) (204.4) (205.9) (189.0) Federal tax credits (208.4) (236.6) (209.8) (236.6) Regulatory liabilities (72.0) (81.0) (72.0) (81.0) Asset retirement obligations (19.4) (20.3) (19.4) (20.3) Postretirement medical and life insurance benefits (19.2) (22.4) (13.0) (15.3) Accrued liabilities (9.5) (9.6) (7.3) (5.2) Deferred federal investment tax credits (3.1) (2.7) (3.1) (2.7) Net operating losses (1.0) (12.0) — (1.4) Accrued vacation (1.5) (2.2) (1.2) (1.6) Uncollectible accounts (0.6) (0.7) (0.6) (0.7) Total deferred income tax liabilities, net $ 1,333.3 $ 1,268.6 $ 1,000.4 $ 1,020.8 As of December 31, 2021, the Registrants have classified $18.1 million of unrecognized tax benefits as a reduction of deferred tax assets recorded. Management is currently unaware of any issues under review that could result in significant additional payments, accruals or other material deviation from this amount. The following table presents a reconciliation of the Registrants' total gross unrecognized tax benefits as of the years ended December 31, 2021, 2020 and 2019. (In millions) 2021 2020 2019 Balance at January 1 $ 21.9 $ 20.7 $ 20.7 Tax positions related to current year: Additions 1.7 1.2 — Reductions (1.2) — — Balance at December 31 $ 22.4 $ 21.9 $ 20.7 As of December 31, 2021, 2020 and 2019, there were $18.1 million, $17.6 million and $16.4 million, respectively, of unrecognized tax benefits that, if recognized, would affect the annual effective tax rate. Where applicable, the Registrants classify income tax-related interest and penalties as interest expense and other expense, respectively. During the year ended December 31, 2021, there were no income tax-related interest or penalties recorded with regard to uncertain tax positions. The Registrants recognize tax benefits from an uncertain tax position only if it is more likely than not the tax position will be sustained on examination by taxing authorities based on the technical merits of the position. The tax benefits in the financial statements from such positions are then measured based on the largest benefit that has a greater than 50 percent likelihood of being realized on settlement. In September 2021, the Registrants recorded an additional reserve for certain federal research and development credits in the amount of $1.7 million. The $1.2 million reserve recorded in 2020 was reversed upon completion of the audit. The Registrants sustained federal and state tax operating losses through 2012 caused primarily by bonus depreciation and other book versus tax temporary differences. Federal net operating losses generated during those years have been fully utilized. State operating losses are being carried forward for utilization in future years. In addition to the tax operating losses, the Registrants were unable to utilize the various tax credits that were generated during those years. These tax losses and credits are being carried as deferred tax assets and will be utilized in future periods. Under current law, the Registrants anticipate future taxable income will be sufficient to utilize remaining losses and credits before they begin to expire after 2021. The following table presents a summary of these carry forwards. OGE Energy OG&E (In millions) Carry Forward Amount Deferred Tax Asset Carry Forward Amount Deferred Tax Asset Earliest Expiration Date State operating loss $ 33.4 $ 1.0 $ — $ — 2032 Federal tax credits $ 208.4 $ 208.4 $ 209.8 $ 209.8 2032 State tax credits: Oklahoma investment tax credits $ 227.1 $ 179.4 $ 207.8 $ 164.2 N/A Oklahoma capital investment board credits $ 12.8 $ 12.8 $ 12.8 $ 12.8 N/A Oklahoma zero emission tax credits $ 37.5 $ 28.9 $ 37.5 $ 28.9 2021 Louisiana inventory credits $ 0.1 $ 0.1 $ — $ — 2032 N/A - not applicable Oklahoma Corporate Tax Rate Change In May 2021, Oklahoma enacted a reduction of the corporate income tax rate to four percent from the previous six percent. This rate reduction took effect on January 1, 2022. ASC 740, "Income Taxes," requires deferred tax assets and liabilities to be measured at the enacted tax rate expected to apply when temporary differences are to be realized or settled. Therefore, during the second quarter of 2021, the Registrants revalued state deferred tax liabilities to reflect this change in tax rate. For entities subject to ASC 980, "Accounting for Regulated Entities," such as OG&E, those entities are required to recognize a regulatory liability for the decrease in taxes payable for the change in tax rates that are expected to be returned to customers through future rates and to recognize a regulatory asset for the increase in taxes receivable for the change in tax rates that are expected to be recovered from customers through future rates. The revaluation resulted in a regulatory liability of $97.7 million recorded for OG&E and an income tax benefit of $6.6 million for OGE Energy related to Enable and other operations (holding company) for the year ended December 31, 2021.

Common Equity

Common Equity	12 Months Ended
	Dec. 31, 2021
Equity [Abstract]
Common Equity	Common Equity OGE Energy Automatic Dividend Reinvestment and Stock Purchase Plan OGE Energy issued no shares of common stock under its Automatic Dividend Reinvestment and Stock Purchase Plan in 2021. OGE Energy may, from time to time, issue shares under its Automatic Dividend Reinvestment and Stock Purchase Plan or purchase shares traded on the open market. At December 31, 2021, there were 4,774,442 shares of unissued common stock reserved for issuance under OGE Energy's Automatic Dividend Reinvestment and Stock Purchase Plan. Earnings (Loss) Per Share Basic earnings (loss) per share is calculated by dividing net income (loss) attributable to OGE Energy by the weighted average number of OGE Energy's common shares outstanding during the period. In the calculation of diluted earnings (loss) per share, weighted average shares outstanding are increased for additional shares that would be outstanding if potentially dilutive securities were converted to common stock. Potentially dilutive securities for OGE Energy consist of performance units and restricted stock units. The following table presents the calculation of basic and diluted earnings (loss) per share for OGE Energy. (In millions except per share data) 2021 2020 2019 Net income (loss) $ 737.3 $ (173.7) $ 433.6 Average common shares outstanding: Basic average common shares outstanding 200.1 200.1 200.1 Effect of dilutive securities: Contingently issuable shares (performance and restricted stock units) 0.2 — 0.6 Diluted average common shares outstanding 200.3 200.1 200.7 Basic earnings (loss) per average common share $ 3.68 $ (0.87) $ 2.17 Diluted earnings (loss) per average common share $ 3.68 $ (0.87) $ 2.16 Anti-dilutive shares excluded from earnings per share calculation — 0.3 — Dividend Restrictions OGE Energy's Certificate of Incorporation places restrictions on the amount of common stock dividends it can pay when preferred stock is outstanding. Before OGE Energy can pay any dividends on its common stock, the holders of any of its preferred stock that may be outstanding are entitled to receive their dividends at the respective rates as may be provided for the shares of their series. As there is no preferred stock outstanding, that restriction did not place any effective limit on OGE Energy's ability to pay dividends to its shareholders. OGE Energy utilizes dividends from OG&E to pay dividends to its shareholders. Prior to December 2021, OGE Energy utilized receipts from its equity method investment in Enable to pay dividends to its shareholders. In light of the completed Energy Transfer merger, OGE Energy expects to utilize, in part, cash distributions from Energy Transfer to pay dividends to its shareholders. Pursuant to the leverage restriction in OGE Energy's revolving credit agreement, OGE Energy must maintain a percentage of debt to total capitalization at a level that does not exceed 65 percent. The payment of cash dividends indirectly results in an increase in the percentage of debt to total capitalization, which results in the restriction of approximately $1.6 billion of OGE Energy's retained earnings from being paid out in dividends. Accordingly, approximately $1.4 billion of OGE Energy's retained earnings as of December 31, 2021 are unrestricted for the payment of dividends. OG&E There were no new shares of OG&E common stock issued in 2021, 2020 or 2019. Dividend Restrictions

Long-Term Debt

Long-Term Debt	12 Months Ended
	Dec. 31, 2021
Long-term Debt, Unclassified [Abstract]
Long-Term Debt	Long-Term Debt A summary of the Registrants' long-term debt is included in the statements of capitalization. At December 31, 2021, the Registrants were in compliance with all of their debt agreements. Maturities of OGE Energy's long-term debt during the next five years consist of $1.0 billion in 2023 and $79.4 million in 2025. Maturities of OG&E's long-term debt during the next five years consist of $500.0 million in 2023 and $79.4 million in 2025. All other long-term debt of the Registrants matures after 2026. The Registrants have previously incurred costs related to debt refinancing. Unamortized loss on reacquired debt is classified as a Non-Current Regulatory Asset in the balance sheets. Unamortized debt expense and unamortized premium and discount on long-term debt are classified as Long-Term Debt in the balance sheets and are being amortized over the life of the respective debt. OG&E Industrial Authority Bonds OG&E has tax-exempt pollution control bonds with optional redemption provisions that allow the holders to request repayment of the bonds on any business day. The following table presents information about these bonds, which can be tendered at the option of the holder during the next 12 months. Series Date Due Amount (In millions) 0.11% - 0.27% Garfield Industrial Authority, January 1, 2025 $ 47.0 0.11% - 0.33% Muskogee Industrial Authority, January 1, 2025 32.4 0.11% - 0.27% Muskogee Industrial Authority, June 1, 2027 56.0 Total (redeemable during next 12 months) $ 135.4 All of these bonds are subject to an optional tender at the request of the holders, at 100 percent of the principal amount, together with accrued and unpaid interest to the date of purchase. The bond holders, on any business day, can request repayment of the bond by delivering an irrevocable notice to the tender agent stating the principal amount of the bond, payment instructions for the purchase price and the business day the bond is to be purchased. The repayment option may only be exercised by the holder of a bond for the principal amount. When a tender notice has been received by the trustee, a third-party remarketing agent for the bonds will attempt to remarket any bonds tendered for purchase. This process occurs once per week. Since the original issuance of these series of bonds in 1995 and 1997, the remarketing agent has successfully remarketed all tendered bonds. If the remarketing agent is unable to remarket any such bonds, OG&E is obligated to repurchase such unremarketed bonds. As OG&E has both the intent and ability to refinance the bonds on a long-term basis and such ability is supported by an ability to consummate the refinancing, the bonds are classified as Long-Term Debt in the balance sheets. OG&E believes that it has sufficient liquidity to meet these obligations. Issuance of Long-Term Debt

Short-Term Debt and Credit Faci

Short-Term Debt and Credit Facilities	12 Months Ended
	Dec. 31, 2021
Short-term Debt [Abstract]
Short-Term Debt and Credit Facilities	Short-Term Debt and Credit Facilities The Registrants borrow on a short-term basis, as necessary, by the issuance of commercial paper and by borrowings under their revolving credit agreements. OGE Energy also borrows under term credit agreements maturing in one year or less, as necessary. As of December 31, 2021, OGE Energy had $486.9 million short-term debt as compared to $95.0 million short-term debt at December 31, 2020. At December 31, 2021, OG&E had $101.3 million in advances from OGE Energy compared to $272.0 million in advances to OGE Energy at December 31, 2020. In March 2021, OGE Energy entered into a $1.0 billion unsecured 364-day term loan agreement and borrowed the full $1.0 billion to help cover the increased fuel and purchased power costs incurred by OG&E during Winter Storm Uri. The term loan contained substantially the same covenants as OGE Energy's revolving credit agreement in place at that time, including various financial ratio covenants. Contemporaneously with the closing of the term loan agreement, in March 2021, OGE Energy made a capital contribution of $530.0 million to OG&E using the term loan proceeds, and OGE Energy also loaned $470.0 million to OG&E pursuant to an intercompany note issued by OG&E to OGE Energy. In May 2021, OG&E repaid the $470.0 million to OGE Energy, and OGE Energy used this repayment and other funds from its issuance of senior notes in May 2021 to repay $900.0 million of the $1.0 billion term loan, as further discussed in Note 11. In December 2021, OGE Energy repaid the remaining $100.0 million outstanding that was borrowed under the term loan agreement. On December 17, 2021, OGE Energy and OG&E each entered into new $550.0 million unsecured five-year revolving credit facilities to replace existing facilities. Each of these new facilities is scheduled to terminate on December 17, 2026. However, each of OGE Energy and OG&E have the right to request an extension of the revolving credit facility termination date under their respective facility for an additional one-year period, which extension option can be exercised up to two times. All such extension requests are subject to majority lender group approval (and only the commitments of those lenders that consent to such extension (or that agree to replace any non-consenting lender) will be extended for such additional period). Borrowings under OGE Energy's new facility bear interest at rates equal to either the eurodollar base rate (reserve adjusted, if applicable), plus a margin of 0.80 percent to 1.475 percent, or an alternate base rate, plus a margin of 0.0 percent to 0.475 percent. OGE Energy's new facility has a facility fee that ranges from 0.075 percent to 0.275 percent. Interest rate margins and facility fees are based on OGE Energy's then-current senior unsecured credit ratings. Borrowings under OG&E's new facility shall bear interest at rates equal to either the eurodollar base rate (reserve adjusted, if applicable), plus a margin of 0.69 percent to 1.275 percent, or an alternate base rate, plus a margin of 0.0 percent to 0.275 percent. OG&E's new facility has a facility fee that ranges from 0.06 percent to 0.225 percent. Both OGE Energy's and OG&E's new facilities include customary LIBOR replacement language. Interest rate margins and facility fees for both OGE Energy and OG&E are based on each of their then-current senior unsecured credit ratings. Each of the facilities contains a mechanism which, subject to approval by the respective borrower, the sustainability structuring agent, and the required lenders, permits a reduction in the applicable margin and/or facility fees if the respective borrower meets certain environmental, social and governance targets. Each of the facilities provides for issuance of letters of credit, provided that (i) the aggregate outstanding credit exposure shall not exceed the amount of the revolving credit facilities and (ii) the aggregate outstanding stated amount of letters of credit issued under such facility shall not exceed a specified maximum sublimit ($100.0 million for each of OGE Energy and OG&E). Advances under the facilities may be used to refinance existing indebtedness and for working capital and general corporate purposes of the respective borrower and its subsidiaries, including commercial paper liquidity support, letters of credit, acquisitions and distributions. Each of the facilities is unsecured and, under certain circumstances, may be increased (by up to $150.0 million in each case for OGE Energy and OG&E), to a maximum revolving commitment limit of $700.0 million for each of OGE Energy and OG&E. Advances of revolving loans and letters of credit under the facilities are subject to certain conditions precedent, including the accuracy of certain representations and warranties and the absence of any default or unmatured default. The following table presents information regarding the Registrants' revolving credit agreements at December 31, 2021. Aggregate Amount Weighted-Average Entity Commitment Outstanding (A) Interest Rate Expiration (In millions) OGE Energy (B) $ 550.0 $ 486.9 0.36 % (E) December 17, 2026 OG&E (C)(D) 550.0 0.4 1.15 % (E) December 17, 2026 Total $ 1,100.0 $ 487.3 0.36 % (A) Includes direct borrowings under the revolving credit agreements, commercial paper borrowings and letters of credit at December 31, 2021. (B) This bank facility is available to back up OGE Energy's commercial paper borrowings and to provide revolving credit borrowings. This bank facility can also be used as a letter of credit facility. (C) This bank facility is available to back up OG&E's commercial paper borrowings and to provide revolving credit borrowings. This bank facility can also be used as a letter of credit facility. (D) OG&E has an intercompany borrowing agreement with OGE Energy whereby OG&E has access to up to $350.0 million of OGE Energy's revolving credit amount. This agreement has a termination date of December 17, 2026. At December 31, 2021, there were $60.0 million in intercompany borrowings under this agreement. (E) Represents the weighted-average interest rate for the outstanding borrowings under the revolving credit agreements, commercial paper borrowings and letters of credit. The Registrants' credit facilities each have a financial covenant requiring that the respective borrower maintain a maximum debt to capitalization ratio of 65 percent, as defined in each such facility. The Registrants' facilities each also contain covenants which restrict the respective borrower and certain of its subsidiaries in respect of, among other things, mergers and consolidations, sales of all or substantially all assets, incurrence of liens and transactions with affiliates. The Registrants' facilities are each subject to acceleration upon the occurrence of any default, including, among others, payment defaults on such facilities, breach of representations, warranties and covenants, acceleration of indebtedness (other than intercompany and non-recourse indebtedness) of $100.0 million or more in the aggregate, change of control (as defined in each such facility), nonpayment of uninsured judgments in excess of $100.0 million and the occurrence of certain Employee Retirement Income Security Act and bankruptcy events, subject where applicable to specified cure periods. The Registrants' ability to access the commercial paper market could be adversely impacted by a credit ratings downgrade or major market disruptions. Pricing grids associated with the Registrants' credit facilities could cause annual fees and borrowing rates to increase if an adverse rating impact occurs. The impact of any future downgrade could include an increase in the costs of the Registrants' short-term borrowings, but a reduction in the Registrants' credit ratings would not result in any defaults or accelerations. Any future downgrade could also lead to higher long-term borrowing costs and, if below investment grade, would require the Registrants to post collateral or letters of credit.

Retirement Plans and Postretire

Retirement Plans and Postretirement Benefit Plans	12 Months Ended
	Dec. 31, 2021
Retirement Plans and Postretirement Benefit Plans [Abstract]
Pension and Other Postretirement Benefits Disclosure [Text Block]	Retirement Plans and Postretirement Benefit Plans OGE Energy sponsors defined benefit pension plans, 401(k) savings plans and other postretirement plans covering certain employees of the Registrants. Pension Plan and Restoration of Retirement Income Plan It is OGE Energy's policy to fund the Pension Plan on a current basis based on the net periodic pension expense as determined by OGE Energy's actuarial consultants. Such contributions are intended to provide not only for benefits attributed to service to date but also for those expected to be earned in the future. OGE Energy made a $40.0 million and $20.0 million contribution to its Pension Plan in 2021 and 2020, of which $30.0 million and $10.0 million was attributed to OG&E in 2021 and 2020, respectively. OGE Energy does not expect it will need to make any contributions to the Pension Plan in 2022. Any contribution to the Pension Plan during 2022 would be a discretionary contribution, anticipated to be in the form of cash, and is not required to satisfy the minimum regulatory funding requirement specified by the Employee Retirement Income Security Act of 1974, as amended. OGE Energy could be required to make additional contributions if the value of its pension trust and postretirement benefit plan trust assets are adversely impacted by a major market disruption in the future. In accordance with ASC Topic 715, "Compensation - Retirement Benefits," a one-time settlement charge is required to be recorded by an organization when lump sum payments or other settlements that relieve the organization from the responsibility for the pension benefit obligation during the plan year exceed the service cost and interest cost components of the organization's net periodic pension cost. During 2021, 2020 and 2019, the Registrants experienced an increase in both the number of employees electing to retire and the amount of lump sum payments paid to such employees upon retirement, which resulted in the Registrants recording pension plan settlement charges as presented in the Pension Plan net periodic benefit cost table. The pension settlement charges did not require a cash outlay by the Registrants and did not increase total pension expense over time, as the charges were an acceleration of costs that otherwise would be recognized as pension expense in future periods. OGE Energy provides a Restoration of Retirement Income Plan to those participants in OGE Energy's Pension Plan whose benefits are subject to certain limitations of the Code. Participants in the Restoration of Retirement Income Plan receive the same benefits that they would have received under OGE Energy's Pension Plan in the absence of limitations imposed by the federal tax laws. The Restoration of Retirement Income Plan is intended to be an unfunded plan. OG&E's employees participate in OGE Energy's Pension Plan and Restoration of Retirement Income Plan. Obligations and Funded Status The details of the funded status of OGE Energy's Pension Plan, the Restoration of Retirement Income Plan and the postretirement benefit plans and the amounts included in the balance sheets for 2021 and 2020 are included in the following tables. These amounts have been recorded in Accrued Benefit Obligations with the offset in Accumulated Other Comprehensive Loss (except OG&E's portion, which is recorded as a regulatory asset as discussed in Note 1) in the balance sheets. The amounts in Accumulated Other Comprehensive Loss and those recorded as a regulatory asset represent a net periodic benefit cost to be recognized in the statements of income in future periods. The benefit obligation for OGE Energy's Pension Plan and the Restoration of Retirement Income Plan represents the projected benefit obligation, while the benefit obligation for the postretirement benefit plans represents the accumulated postretirement benefit obligation. The accumulated postretirement benefit obligation for OGE Energy's Pension Plan and Restoration of Retirement Income Plan differs from the projected benefit obligation in that the former includes no assumption about future compensation levels. OGE Energy's seconded employee contract with Enable was terminated on December 2, 2021. OGE Energy retains the obligations to the balances and accrued benefits of these former employees as of the termination of the contract. OGE Energy OG&E Pension Plan Restoration of Retirement Pension Plan Restoration of Retirement December 31 (In millions) 2021 2020 2021 2020 2021 2020 2021 2020 Change in benefit obligation Beginning obligations $ 654.6 $ 616.1 $ 7.8 $ 10.3 $ 484.1 $ 462.0 $ 3.0 $ 6.1 Service cost 11.2 13.2 0.8 0.8 7.7 9.2 — 0.1 Interest cost 13.3 17.0 0.1 0.2 9.7 12.6 — 0.1 Plan settlements (158.6) (42.8) (4.6) (5.3) (120.4) (33.5) (2.9) (4.5) Plan amendments — — 1.4 — — — — — Plan curtailments — — (0.1) 0.2 — — — — Special termination benefits — 7.6 — — — 5.1 — — Actuarial (gains) losses (3.5) 57.7 0.5 1.6 (6.0) 41.0 0.4 1.2 Benefits paid (14.1) (14.2) — — (11.9) (12.3) — — Ending obligations $ 502.9 $ 654.6 $ 5.9 $ 7.8 $ 363.2 $ 484.1 $ 0.5 $ 3.0 Change in plans' assets Beginning fair value $ 570.3 $ 530.3 $ — $ — $ 420.3 $ 399.1 $ — $ — Actual return on plans' assets 48.4 77.0 — — 35.0 57.0 — — Employer contributions 40.0 20.0 4.6 5.3 30.0 10.0 2.9 4.5 Plan settlements (158.6) (42.8) (4.6) (5.3) (120.4) (33.5) (2.9) (4.5) Benefits paid (14.1) (14.2) — — (11.9) (12.3) — — Ending fair value $ 486.0 $ 570.3 $ — $ — $ 353.0 $ 420.3 $ — $ — Funded status at end of year $ (16.9) $ (84.3) $ (5.9) $ (7.8) $ (10.2) $ (63.8) $ (0.5) $ (3.0) Accumulated postretirement benefit obligation $ 475.2 $ 610.8 $ 5.4 $ 6.9 $ 341.0 $ 454.7 $ 0.4 $ 2.9 For the year ended December 31, 2021, Pension Plan actuarial gains were primarily due to favorable demographic experience and a higher discount rate. These gains were partially offset by a difference in lump sum interest rates and the long-term assumption for Enable seconded employee terminations and more retirements and terminations than expected with lump sum payouts. For the year ended December 31, 2020, Pension Plan actuarial losses were primarily due to movement in the discount rate, special termination benefits due to a voluntary retirement program offered by OGE Energy and more retirements and terminations than expected which were expected to accelerate lump sum payments in 2021. These losses were partially offset by gains from lowering the interest crediting rate and plan mortality assumptions. OGE Energy OG&E Postretirement Benefit Plans Postretirement Benefit Plans December 31 (In millions) 2021 2020 2021 2020 Change in benefit obligation Beginning obligations $ 144.5 $ 136.5 $ 109.5 $ 104.7 Service cost 0.2 0.2 0.1 0.2 Interest cost 3.4 4.2 2.6 3.2 Plan curtailments 1.9 4.0 — 3.1 Participants' contributions 3.5 3.3 2.6 2.4 Actuarial (gains) losses (3.7) 7.3 (2.5) 4.5 Benefits paid (12.5) (11.0) (9.9) (8.6) Ending obligations $ 137.3 $ 144.5 $ 102.4 $ 109.5 Change in plans' assets Beginning fair value $ 47.6 $ 47.0 $ 42.7 $ 41.9 Actual return on plans' assets (0.5) 1.2 (0.5) 1.1 Employer contributions 6.2 7.1 5.0 5.9 Participants' contributions 3.5 3.3 2.6 2.4 Benefits paid (12.5) (11.0) (9.9) (8.6) Ending fair value $ 44.3 $ 47.6 $ 39.9 $ 42.7 Funded status at end of year $ (93.0) $ (96.9) $ (62.5) $ (66.8) Curtailment loss for the year ended December 31, 2021 is related to Enable seconded employees who terminated employment as a result of the merger with Energy Transfer. This reduction in future service of the active participants triggered curtailment accounting as of December 31, 2021. Special termination benefits and curtailment loss for the year ended December 31, 2020 are related to a voluntary retirement program offered by OGE Energy in the fourth quarter of 2020. A curtailment gain or loss is required when the expected future services or benefits in a benefit plan are significantly reduced or eliminated. Net Periodic Benefit Cost The following tables present the net periodic benefit cost components, before consideration of capitalized amounts, of OGE Energy's Pension Plan, Restoration of Retirement Income Plan and postretirement benefit plans that are included in the financial statements. Service cost is presented within Other Operation and Maintenance Expense, and the remaining net period benefit cost components as listed in the following tables are presented within Other Net Periodic Benefit Expense in the statements of income. OG&E recovers specific amounts of pension and postretirement medical costs in rates approved in its Oklahoma rate reviews. In accordance with approved orders, OG&E defers the difference between actual pension and postretirement medical expenses and the amount approved in its last Oklahoma rate review as a regulatory asset or regulatory liability. These amounts have been recorded in the Pension tracker in the regulatory assets and liabilities table in Note 1 and within Other Net Periodic Benefit Expense in the statements of income. OGE Energy OG&E Pension Plan Restoration of Retirement Pension Plan Restoration of Retirement Year Ended December 31 (In millions) 2021 2020 2019 2021 2020 2019 2021 2020 2019 2021 2020 2019 Service cost $ 11.2 $ 13.2 $ 12.9 $ 0.8 $ 0.8 $ 0.5 $ 7.7 $ 9.2 $ 9.0 $ — $ 0.1 $ 0.2 Interest cost 13.3 17.0 20.7 0.1 0.2 0.4 9.7 12.6 15.6 — 0.1 0.2 Expected return on plan assets (34.1) (37.6) (36.1) — — — (24.7) (27.9) (27.6) — — — Amortization of net loss 9.4 17.1 17.3 0.2 0.5 0.5 7.0 12.1 12.9 0.1 0.4 0.3 Plan curtailments — — — — 0.2 — — — — — — — Special termination benefits — 7.6 — — — — — 5.1 — — — — Amortization of unrecognized prior service cost (A) — — — 0.1 — — — — — — — — Settlement cost 41.3 14.1 27.6 2.1 2.7 0.5 33.1 11.4 16.4 1.6 2.4 0.5 Total net periodic benefit cost 41.1 31.4 42.4 3.3 4.4 1.9 32.8 22.5 26.3 1.7 3.0 1.2 Less: Amount paid by unconsolidated affiliates (B) (0.2) 2.0 2.9 0.1 0.1 0.1 Plus: Amount allocated from OGE Energy (B) 6.5 5.9 4.5 1.5 1.3 0.5 Net periodic benefit cost $ 41.3 $ 29.4 $ 39.5 $ 3.2 $ 4.3 $ 1.8 $ 39.3 $ 28.4 $ 30.8 $ 3.2 $ 4.3 $ 1.7 (A) Unamortized prior service cost is amortized on a straight-line basis over the average remaining service period to the first eligibility age of participants who are expected to receive a benefit and are active at the date of the plan amendment. (B) "Amount paid by unconsolidated affiliates" is only applicable to OGE Energy. "Amount allocated from OGE Energy" is only applicable to OG&E. In conjunction with the net periodic benefit cost amounts recognized, as presented in the table above, for the Pension and Restoration of Retirement Income Plans in 2021, 2020 and 2019, the Registrants recognized the following: Year Ended December 31 (In millions) 2021 2020 2019 Increase of regulatory asset related to pension expense to maintain allowed recoverable amount in Oklahoma jurisdiction (A) $ 23.0 $ 13.8 $ 16.1 Deferral of pension expense related to pension settlement, curtailment and special termination benefits charges included in the above line item: Oklahoma jurisdiction (A) $ 37.9 $ 21.6 $ 17.9 Arkansas jurisdiction (A) $ 3.5 $ 2.0 $ 1.7 (A) Included in the pension regulatory asset or liability in each jurisdiction, as indicated in the regulatory assets and liabilities table in Note 1. OGE Energy OG&E Postretirement Benefit Plans Postretirement Benefit Plans Year Ended December 31 (In millions) 2021 2020 2019 2021 2020 2019 Service cost $ 0.2 $ 0.2 $ 0.2 $ 0.1 $ 0.2 $ 0.2 Interest cost 3.4 4.2 5.6 2.6 3.2 4.3 Expected return on plan assets (1.8) (1.8) (1.9) (1.7) (1.7) (1.7) Amortization of net loss 2.8 2.0 2.0 2.7 2.1 2.1 Plan curtailments — 1.5 — — 1.3 — Amortization of unrecognized prior service cost (A) (6.9) (8.4) (8.4) (5.0) (6.1) (6.1) Total net periodic benefit income (2.3) (2.3) (2.5) (1.3) (1.0) (1.2) Less: Amount paid by unconsolidated affiliates (B) (0.5) (0.7) (0.6) Plus: Amount allocated from OGE Energy (B) (0.5) (0.5) (0.6) Net periodic benefit income $ (1.8) $ (1.6) $ (1.9) $ (1.8) $ (1.5) $ (1.8) (A) Unamortized prior service cost is amortized on a straight-line basis over the average remaining service period to the first eligibility age of participants who are expected to receive a benefit and are active at the date of the plan amendment. (B) "Amount paid by unconsolidated affiliates" is only applicable to OGE Energy. "Amount allocated from OGE Energy" is only applicable to OG&E. In conjunction with the net periodic benefit income amounts recognized, as presented in the table above, for the postretirement benefit plans in 2021, 2020 and 2019, the Registrants recognized the following: Year Ended December 31 (In millions) 2021 2020 2019 Increase of regulatory liability related to postretirement expense to maintain allowed recoverable amount in Oklahoma jurisdiction (A) $ 0.4 $ 0.2 $ 1.0 Deferral of postretirement expense related to postretirement plan curtailment charges included in the above line item: Oklahoma jurisdiction (A) $ — $ (1.4) $ — Arkansas jurisdiction (A) $ — $ (0.1) $ — (A) Included in the pension regulatory asset or liability in each jurisdiction, as indicated in the regulatory assets and liabilities table in Note 1. The following table presents the amount of net periodic benefit cost capitalized and attributable to each of the Registrants for OGE Energy's Pension Plan and postretirement benefit plans in 2021, 2020 and 2019. OGE Energy OG&E (In millions) 2021 2020 2019 2021 2020 2019 Capitalized portion of net periodic pension benefit cost $ 3.4 $ 3.8 $ 3.6 $ 2.9 $ 3.1 $ 3.0 Capitalized portion of net periodic postretirement benefit cost $ 0.2 $ 0.2 $ 0.2 $ 0.1 $ 0.1 $ 0.1 Rate Assumptions Pension Plan and Postretirement Year Ended December 31 2021 2020 2019 2021 2020 2019 Assumptions to determine benefit obligations: Discount rate 2.75 % 2.30 % 3.15 % 2.80 % 2.45 % 3.25 % Rate of compensation increase 4.20 % 4.20 % 4.20 % N/A N/A N/A Interest crediting rate 3.50 % 3.50 % 4.00 % N/A N/A N/A Assumptions to determine net periodic benefit cost: Discount rate 2.63 % 2.88 % 3.63 % 2.45 % 3.25 % 4.30 % Expected return on plan assets 7.00 % 7.50 % 7.50 % 4.00 % 4.00 % 4.00 % Rate of compensation increase 4.20 % 4.20 % 4.20 % N/A N/A N/A Interest crediting rate 3.50 % 4.00 % 4.00 % N/A N/A N/A N/A - not applicable The discount rate used to compute the present value of plan liabilities is based generally on rates of high-grade corporate bonds with maturities similar to the average period over which benefits will be paid. The discount rate used to determine net benefit cost for the current year is the same discount rate used to determine the benefit obligation as of the previous year's balance sheet date, unless a plan settlement occurs during the current year that requires an updated discount rate for net periodic cost measurement. For 2021 and 2020, the Pension Plan discount rates used to determine net periodic benefit cost are disclosed on a weighted-average basis. The overall expected rate of return on plan assets assumption is used in determining net periodic benefit cost due to recent returns on OGE Energy's long-term investment portfolio. The rate of return on plan assets assumption is the average long-term rate of earnings expected on the funds currently invested and to be invested for the purpose of providing benefits specified by the Pension Plan or postretirement benefit plans. This assumption is reexamined at least annually and updated as necessary. The rate of return on plan assets assumption reflects a combination of historical return analysis, forward-looking return expectations and the plans' current and expected asset allocation. The assumed health care cost trend rates have a significant effect on the amounts reported for postretirement medical benefit plans. Future health care cost trend rates are assumed to be 6.50 percent in 2022 with the rates trending downward to 4.50 percent by 2030. Pension Plan Pension Plan Investments, Policies and Strategies The Pension Plan assets are held in a trust which follows an investment policy and strategy designed to reduce the funded status volatility of the Plan by utilizing liability driven investing. The purpose of liability-driven investing is to structure the asset portfolio to more closely resemble the pension liability and thereby more effectively hedge against changes in the liability. The investment policy follows a glide path approach that shifts a higher portfolio weighting to fixed income as the Plan's funded status increases. The following table presents the targeted fixed income and equity allocations at different funded status levels. Projected Benefit Obligation Funded Status Thresholds <90% 95% 100% 105% 110% 115% 120% Fixed income 50% 58% 65% 73% 80% 85% 90% Equity 50% 42% 35% 27% 20% 15% 10% Total 100% 100% 100% 100% 100% 100% 100% Within the portfolio's overall allocation to equities, the funds are allocated according to the guidelines in the following table. Asset Class Target Allocation Minimum Maximum Domestic Large Cap Equity 40% 35% 60% Domestic Mid-Cap Equity 15% 5% 25% Domestic Small-Cap Equity 25% 5% 30% International Equity 20% 10% 30% OGE Energy has retained an investment consultant responsible for the general investment oversight, analysis, monitoring investment guideline compliance and providing quarterly reports to certain of the Registrants' members and OGE Energy's Investment Committee. The various investment managers used by the trust operate within the general operating objectives as established in the investment policy and within the specific guidelines established for each investment manager's respective portfolio. The portfolio is rebalanced at least on an annual basis to bring the asset allocations of various managers in line with the target asset allocation listed above. More frequent rebalancing may occur if there are dramatic price movements in the financial markets which may cause the trust's exposure to any asset class to exceed or fall below the established allowable guidelines. To evaluate the progress of the portfolio, investment performance is reviewed quarterly. It is, however, expected that performance goals will be met over a full market cycle, normally defined as a three- to five-year period. Analysis of performance is within the context of the prevailing investment environment and the advisors' investment style. The goal of the trust is to provide a rate of return consistently from three percent to five percent over the rate of inflation (as measured by the national Consumer Price Index) on a fee adjusted basis over a typical market cycle of no less than three years and no more than five years. Each investment manager is expected to outperform its respective benchmark. The following table presents a list of each asset class utilized with appropriate comparative benchmark(s) each manager is evaluated against and the focus of the asset class. Asset Class Comparative Benchmark(s) Focus of Asset Class Active Duration Fixed Income (A)(B) Bloomberg Barclays Aggregate l Maximize risk-adjusted performance while providing long bond exposure managed according to the manager's forecast on interest rates. l All invested assets must reach at or above Baa3 or BBB- investment grade. l Limited five percent exposure to any single issuer, except the U.S. Government or affiliates. Long Duration Fixed Income (A)(B) Duration blended Barclays Long Government/Credit & Barclays Universal l Maximize risk-adjusted performance. l At least 75 percent of invested assets much reach at or above Baaa3 or BBB- investment grade. l Limited five percent exposure to any single issuer, except the U.S. Government or affiliates. l May invest up to 10 percent of the market value in convertible bonds as long as quality guidelines are met. l May invest up to 15 percent of the market value in private placement, including 144A securities with or without registration rights and allow for futures to be traded in the portfolio. Equity Index (B)(C) Standard & Poor's 500 Index l Focus on replicating the performance of the S&P 500 Index. Mid-Cap Equity (B)(C) Russell Midcap Index l Focus on undervalued stocks expected to earn average return and pay out higher than average dividends. l Invest in companies with market capitalizations lower than average company on public exchanges: l Price/earnings ratio at or near referenced index; l Small dividend yield and return on equity at or near referenced index; and l Earnings per share growth rate at or near referenced index. Small-Cap Equity (B)(C) Russell 2000 Index International Equity (D) Morgan Stanley Capital International ACWI ex-U.S. l Invest in non-dollar denominated equity securities. l Diversify the overall trust investments. (A) Investment grades are by Moody's Investors Service, S&P Global Ratings or Fitch Ratings. (B) The purchase of any of OGE Energy's equity, debt or other securities is prohibited. (C) No more than five percent can be invested in any one stock at the time of purchase and no more than 10 percent after accounting for price appreciation. Options or financial futures may not be purchased unless prior approval from OGE Energy's Investment Committee is received. The purchase of securities on margin, securities lending, private placement purchases and venture capital purchases are prohibited. The aggregate positions in any company may not exceed one percent of the fair market value of its outstanding stock. (D) The manager of this asset class is required to operate under certain restrictions including regional constraints, diversification requirements and percentage of U.S. securities. All securities are freely traded on a recognized stock exchange, and there are no over-the-counter derivatives. The following investment categories are excluded: options (other than traded currency options), commodities, futures (other than currency futures or currency hedging), short sales/margin purchases, private placements, unlisted securities and real estate (but not real estate shares). Pension Plan Investments The following tables present the Pension Plan's investments that are measured at fair value on a recurring basis at December 31, 2021 and 2020. There were no Level 3 investments held by the Pension Plan at December 31, 2021 and 2020. (In millions) December 31, 2021 Level 1 Level 2 Net Asset Value (A) Common stocks $ 86.1 $ 86.1 $ — $ — U.S. Treasury notes and bonds (B) 135.2 135.2 — — Mortgage- and asset-backed securities 24.6 — 24.6 — Corporate fixed income and other securities 107.0 — 107.0 — Commingled fund (C) 23.6 — — 23.6 Foreign government bonds 0.9 — 0.9 — U.S. municipal bonds 1.4 — 1.4 — Money market fund 5.5 — — 5.5 Mutual fund 99.8 99.8 — — Preferred stocks 1.1 1.1 — — U.S. Treasury futures: Cash collateral 0.6 0.6 — — Forward contracts: Receivable (foreign currency) 0.1 — 0.1 — Total Pension Plan investments 485.9 $ 322.8 $ 134.0 $ 29.1 Interest and dividends receivable 2.1 Payable to broker for securities purchased (2.0) Total OGE Energy Pension Plan assets $ 486.0 Pension Plan investments attributable to affiliates (133.0) Total OG&E Pension Plan assets $ 353.0 (A) GAAP allows the measurement of certain investments that do not have a readily determinable fair value at the net asset value. These investments do not consider the observability of inputs; therefore, they are not included within the fair value hierarchy. (B) This category represents U.S. Treasury notes and bonds with a Moody's Investors Service rating of Aaa and Government Agency Bonds with a Moody's Investors Service rating of A1 or higher. (C) This category represents units of participation in a commingled fund that primarily invested in stocks of international companies and emerging markets. (In millions) December 31, 2020 Level 1 Level 2 Net Asset Value (A) Common stocks $ 252.3 $ 252.3 $ — $ — U.S. Treasury notes and bonds (B) 134.3 134.3 — — Mortgage- and asset-backed securities 29.3 — 29.3 — Corporate fixed income and other securities 116.6 — 116.6 — Commingled fund (C) 25.4 — — 25.4 Foreign government bonds 4.6 — 4.6 — U.S. municipal bonds 1.8 — 1.8 — Money market fund 8.8 — — 8.8 Mutual fund 9.2 9.2 — — Preferred stocks 0.6 0.6 — — U.S. Treasury Futures: Cash collateral 0.7 0.7 — — Forward contracts: Receivable (foreign currency) 0.1 — 0.1 — Total Pension Plan investments 583.7 $ 397.1 $ 152.4 $ 34.2 Receivable from broker for securities sold 0.2 Interest and dividends receivable 2.2 Payable to broker for securities purchased (15.8) Total OGE Energy Pension Plan assets $ 570.3 Pension Plan investments attributable to affiliates (150.0) Total OG&E Pension Plan assets $ 420.3 (A) GAAP allows the measurement of certain investments that do not have a readily determinable fair value at the net asset value. These investments do not consider the observability of inputs; therefore, they are not included within the fair value hierarchy. (B) This category represents U.S. Treasury notes and bonds with a Moody's Investors Service rating of Aaa and Government Agency Bonds with a Moody's Investors Service rating of A1 or higher. (C) This category represents units of participation in a commingled fund that primarily invested in stocks of international companies and emerging markets. As defined in the fair value hierarchy, Level 1 inputs are quoted prices in active markets for identical unrestricted assets or liabilities that are accessible by the Pension Plan at the measurement date. Level 2 inputs are inputs other than quoted prices in active markets included within Level 1 that are either directly or indirectly observable at the reporting date for the asset or liability for substantially the full term of the asset or liability. Level 2 inputs include quoted prices for similar assets or liabilities in active markets and quoted prices for identical or similar assets or liabilities in markets that are not active. Level 3 inputs are prices or valuation techniques for the asset or liability that require inputs that are both significant to the fair value measurement and unobservable (i.e., supported by little or no market activity). Unobservable inputs reflect the Plan's own assumptions about the assumptions that market participants would use in pricing the asset or liability (including assumptions about risk). Expected Benefit Payments The following table presents the benefit payments the Registrants expect to pay related to the Pension Plan and Restoration of Retirement Income Plan. These expected benefits are based on the same assumptions used to measure OGE Energy's benefit obligation at the end of the year and include benefits attributable to estimated future employee service. (In millions) OGE Energy OG&E 2022 $ 95.3 $ 38.8 2023 $ 37.0 $ 30.7 2024 $ 38.4 $ 30.6 2025 $ 36.7 $ 28.7 2026 $ 35.2 $ 28.3 2027-2031 $ 167.4 $ 126.6 Postretirement Benefit Plans In addition to providing pension benefits, OGE Energy provides certain medical and life insurance benefits for eligible retired members. Regular, full-time, active employees hired prior to February 1, 2000 whose age and years of credited service total or exceed 80 or have attained at least age 55 with 10 or more years of service at the time of retirement are entitled to postretirement medical benefits, while employees hired on or after February 1, 2000 are not entitled to postretirement medical benefits. Eligible retirees must contribute such amount as OGE Energy specifies from time to time toward the cost of coverage for postretirement benefits. The benefits are subject to deductibles, co-payment provisions and other limitations. OG&E charges postretirement benefit costs to expense and includes an annual amount as a component of the cost-of-service in future ratemaking proceedings. OGE Energy's contribution to the medical costs for pre-65 aged eligible retirees are fixed at the 2011 level, and OGE Energy covers future annual medical inflationary cost increases up to five percent. Increases in excess of five percent annually are covered by the pre-65 aged retiree in the form of premium increases. OGE Energy provides Medicare-eligible retirees and their Medicare-eligible spouses an annual fixed contribution to an OGE Energy-sponsored health reimbursement arrangement. Medicare-eligible retirees are able to purchase individual insurance policies supplemental to Medicare through a third-party administrator and use their health reimbursement arrangement funds for reimbursement of medical premiums and other eligible medical expenses. Postretirement Plans Investments The following tables present the postretirement benefit plans' investments that are measured at fair value on a recurring basis at December 31, 2021 and 2020. There were no Level 2 investments held by the postretirement benefit plans at December 31, 2021 and 2020. (In millions) December 31, 2021 Level 1 Level 3 Group retiree medical insurance contract $ 28.1 $ — $ 28.1 Mutual funds 16.2 16.2 — Total OGE Energy plan investments $ 44.3 $ 16.2 $ 28.1 Plan investments attributable to affiliates (4.4) Total OG&E plan investments $ 39.9 (In millions) December 31, 2020 Level 1 Level 3 Group retiree medical insurance contract $ 33.4 $ — $ 33.4 Mutual funds 14.2 14.2 — Total OGE Energy plan investments $ 47.6 $ 14.2 $ 33.4 Plan investments attributable to affiliates (4.9) Total OG&E plan investments $ 42.7 The group retiree medical insurance contract invests in a pool of common stocks, bonds and money market accounts, of which a significant portion is comprised of mortgage-backed securities. The unobservable input included in the valuation of the contract includes the approach for determining the allocation of the postretirement benefit plans' pro-rata share of the total assets in the contract. The following table presents a reconciliation of the postretirement benefit plans' investments that are measured at fair value on a recurring basis using significant unobservable inputs (Level 3). Year Ended December 31 (In millions) 2021 Group retiree medical insurance contract: Beginning balance $ 33.4 Claims paid (4.9) Net unrealized losses related to instruments held at the reporting date (1.1) Investment fees (0.1) Realized losses (0.1) Interest income 0.7 Dividend income 0.2 Ending balance $ 28.1 Medicare Prescription Drug, Improvement and Modernization Act of 2003 The Medicare Prescription Drug, Improvement and Modernization Act of 2003 expanded coverage for prescription drugs. The following table presents the gross benefit payments the Registrants expect to pay related to the postretirement benefit plans, including prescription drug benefits. (In millions) OGE Energy OG&E 2022 $ 12.5 $ 9.6 2023 $ 12.2 $ 9.3 2024 $ 10.6 $ 8.0 2025 $ 10.1 $ 7.6 2026 $ 9.7 $ 7.2 After 2026 $ 40.3 $ 30.2 Post-Employment Benefit Plan Disabled employees receiving benefits from OGE Energy's Group Long-Term Disability Plan are entitled to continue participating in OGE Energy's Medical Plan along with their dependents. The post-employment benefit obligation represents the actuarial present value of estimated future medical benefits that are attributed to employee service rendered prior to the date as of which such information is presented. The obligation also includes future medical benefits expected to be paid to current employees participating in the Group Long-Term Disability Plan and their dependents, as defined in OGE Energy's Medical Plan. The post-employment benefit obligation is determined by an actuary on a basis similar to the accumulated postretirement benefit obligation. The estimated future medical benefits are projected to grow with expected future medical cost trend rates and are discounted for interest at the discount rate and for the probability that the participant will discontinue receiving benefits from OGE Energy's Group Long-Term Disability Plan due to death, recovery from disability or eligibility for retiree medical benefits. OGE Energy's post-employment benefit obligation was $2.0 million and $2.2 million at December 31, 2021 and 2020, respectively, of which $1.5 million and $1.8 million, respectively, was OG&E's portion of the obligation. 401(k) Plan OGE Energy provides a 401(k) Plan, and each regular full-time employee of OGE Energy or a participating affiliate is eligible to participate in the 401(k) Plan immediately upon hire. All other employees of OGE Energy or a participating affiliate are eligible to become participants in the 401(k) Plan after completing one year of service as defined in the 401(k) Plan. Participants may contribute each pay period any whole percentage between two percent and 19 percent of their compensation, as defined in the 401(k) Plan, for that pay period. Participants who have reached age

Report of Business Segments

Report of Business Segments	12 Months Ended
	Dec. 31, 2021
Segment Reporting Information [Line Items]
Report of Business Segments	Report of Business Segments OGE Energy reports its operations in two business segments: (i) the electric utility segment, which is engaged in the generation, transmission, distribution and sale of electric energy and (ii) natural gas midstream operations segment. Prior to the Enable and Energy Transfer merger closing on December 2, 2021, OGE Energy's natural gas midstream operations segment included its equity method investment in Enable. Subsequent to December 2, 2021, OGE Energy's natural gas midstream operations segment includes its investment in Energy Transfer's equity securities and legacy Enable seconded employee pension and postretirement costs. Other operations primarily includes the operations of the holding company. Intersegment revenues are recorded at prices comparable to those of unaffiliated customers and are affected by regulatory considerations. The following tables present the results of OGE Energy's business segments for the years ended December 31, 2021, 2020 and 2019. 2021 Electric Utility Natural Gas Midstream Operations Other Eliminations Total (In millions) Operating revenues $ 3,653.7 $ — $ — $ — $ 3,653.7 Fuel, purchased power and direct transmission expense 2,127.6 — — — 2,127.6 Other operation and maintenance 464.7 1.6 (3.2) — 463.1 Depreciation and amortization 416.0 — — — 416.0 Taxes other than income 99.3 0.2 3.3 — 102.8 Operating income (loss) 546.1 (1.8) (0.1) — 544.2 Equity in earnings of unconsolidated affiliates — 169.8 — — 169.8 Gain on Enable/Energy Transfer transaction, net — 344.4 — — 344.4 Other income (expense) 7.7 (26.4) (2.0) (0.9) (21.6) Interest expense 152.0 — 7.2 (0.9) 158.3 Income tax expense (benefit) 41.8 101.0 (1.6) — 141.2 Net income (loss) $ 360.0 $ 385.0 $ (7.7) $ — $ 737.3 Total assets $ 11,688.0 $ 786.6 $ 350.3 $ (218.5) $ 12,606.4 Capital expenditures $ 778.5 $ — $ — $ — $ 778.5 2020 Electric Utility Natural Gas Midstream Operations Other Eliminations Total (In millions) Operating revenues $ 2,122.3 $ — $ — $ — $ 2,122.3 Fuel, purchased power and direct transmission expense 644.6 — — — 644.6 Other operation and maintenance 464.4 1.7 (3.3) — 462.8 Depreciation and amortization 391.3 — — — 391.3 Taxes other than income 97.2 0.4 3.8 — 101.4 Operating income (loss) 524.8 (2.1) (0.5) — 522.2 Equity in losses of unconsolidated affiliates (A) — (668.0) — — (668.0) Other income (expense) 4.1 (2.9) 3.6 (1.6) 3.2 Interest expense 154.8 — 5.3 (1.6) 158.5 Income tax expense (benefit) 34.7 (158.0) (4.1) — (127.4) Net income (loss) $ 339.4 $ (515.0) $ 1.9 $ — $ (173.7) Investment in unconsolidated affiliates $ — $ 374.3 $ — $ — $ 374.3 Total assets $ 10,489.0 $ 378.1 $ 116.4 $ (264.7) $ 10,718.8 Capital expenditures $ 650.5 $ — $ — $ — $ 650.5 (A) In March 2020, OGE Energy recorded a $780.0 million impairment on its investment in Enable, as further discussed in Notes 5 and 7. 2019 Electric Utility Natural Gas Midstream Operations Other Eliminations Total (In millions) Operating revenues $ 2,231.6 $ — $ — $ — $ 2,231.6 Fuel, purchased power and direct transmission expense 786.9 — — — 786.9 Other operation and maintenance 492.5 2.8 (3.5) — 491.8 Depreciation and amortization 355.0 — — — 355.0 Taxes other than income 89.5 0.4 3.7 — 93.6 Operating income (loss) 507.7 (3.2) (0.2) — 504.3 Equity in earnings of unconsolidated affiliates — 113.9 — — 113.9 Other income (expense) 3.1 (8.6) 2.2 (3.6) (6.9) Interest expense 140.5 — 11.0 (3.6) 147.9 Income tax expense (benefit) 20.1 20.7 (11.0) — 29.8 Net income $ 350.2 $ 81.4 $ 2.0 $ — $ 433.6 Investment in unconsolidated affiliates $ — $ 1,132.9 $ — $ — $ 1,132.9 Total assets $ 10,076.6 $ 1,135.4 $ 107.0 $ (294.7) $ 11,024.3 Capital expenditures $ 635.5 $ — $ — $ — $ 635.5

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Public Utility Regulatory Policy Act of 1978 OG&E had QF contracts with AES-Shady Point, Inc. and Oklahoma Cogeneration LLC, which expired in January and August 2019, respectively. For the 320 MW AES-Shady Point, Inc. QF contract and the 120 MW Oklahoma Cogeneration LLC QF contract, OG&E purchased 100 percent of the electricity generated by the qualified cogeneration facilities. In 2019, OG&E acquired the plants from AES-Shady Point, Inc. and Oklahoma Cogeneration LLC. Previous to such acquisitions, OG&E made total payments to cogenerators of $14.7 million, of which $7.4 million represented capacity payments. All payments for purchased power, including cogeneration, are included in the Registrants' statements of income as Fuel, Purchased Power and Direct Transmission Expense. Purchase Obligations and Commitments The following table presents the Registrants' future purchase obligations and commitments estimated for the next five years. (In millions) 2022 2023 2024 2025 2026 Total Purchase obligations and commitments: Minimum purchase commitments $ 97.7 $ 50.4 $ 31.2 $ 24.6 $ 24.6 $ 228.5 Expected wind purchase commitments 55.6 56.0 56.6 56.9 57.4 282.5 Long-term service agreement commitments 2.7 2.6 15.0 24.4 9.7 54.4 Total purchase obligations and commitments $ 156.0 $ 109.0 $ 102.8 $ 105.9 $ 91.7 $ 565.4 OG&E Minimum Purchase Commitments OG&E has coal contracts for purchases through December 31, 2022, whereby OG&E has the right but not the obligation to purchase a defined quantity of coal. OG&E may also purchase coal through spot purchases on an as-needed basis. As a participant in the SPP Integrated Marketplace, OG&E purchases its natural gas supply through short-term agreements. OG&E relies on a combination of natural gas base load agreements and call agreements, whereby OG&E has the right but not the obligation to purchase a defined quantity of natural gas, combined with day and intra-day purchases to meet the demands of the SPP Integrated Marketplace. OG&E has natural gas transportation service contracts with Energy Transfer, ONEOK, Inc. and Southern Star. The contracts with Energy Transfer end in May 2024 and December 2038; the contracts with ONEOK, Inc. end in March 2024 and August 2037; and the contract with Southern Star ends in June 2024. These transportation contracts grant Energy Transfer, ONEOK, Inc. and Southern Star the responsibility of delivering natural gas to OG&E's generating facilities. OG&E Wind Purchase Commitments The following table presents OG&E's wind power purchase contracts. Company Location Original Term of Contract Expiration of Contract MWs CPV Keenan Woodward County, OK 20 years 2030 152.0 Edison Mission Energy Dewey County, OK 20 years 2031 130.0 NextEra Energy Blackwell, OK 20 years 2032 60.0 The following table presents a summary of OG&E's wind power purchases for the years ended December 31, 2021, 2020 and 2019. Year Ended December 31 (In millions) 2021 2020 2019 CPV Keenan $ 27.3 $ 27.5 $ 27.2 Edison Mission Energy 21.7 22.8 23.1 NextEra Energy 6.8 7.0 7.4 Total wind power purchased $ 55.8 $ 57.3 $ 57.7 OG&E Long-Term Service Agreement Commitments OG&E has a long-term parts and service maintenance contract for the upkeep of the McClain Plant. In May 2013, a new contract was signed that is expected to run for the earlier of 128,000 factored-fired hours or 4,800 factored-fired starts. In December 2015, the McClain Long-Term Service Agreement was amended to define the terms and conditions for the exchange of spare rotors between OG&E and General Electric International, Inc. Based on historical usage and current expectations for future usage, this contract is expected to run until 2033. The contract requires payments based on both a fixed and variable cost component, depending on how much the McClain Plant is used. OG&E has a long-term parts and service maintenance contract for the upkeep of the Redbud Plant. In March 2013, the contract was amended to extend the contract coverage for an additional 24,000 factored-fired hours resulting in a maximum of the earlier of 144,000 factored-fired hours or 4,500 factored-fired starts. Based on historical usage and current expectations for future usage, this contract is expected to run until 2032. The contract requires payments based on both a fixed and variable cost component, depending on how much the Redbud Plant is used. Environmental Laws and Regulations The activities of the Registrants are subject to numerous stringent and complex federal, state and local laws and regulations governing environmental protection. These laws and regulations can change, restrict or otherwise impact the Registrants' business activities in many ways, including the handling or disposal of waste material, planning for future construction activities to avoid or mitigate harm to threatened or endangered species and requiring the installation and operation of emissions or pollution control equipment. Failure to comply with these laws and regulations could result in the assessment of administrative, civil and criminal penalties, the imposition of remedial requirements and the issuance of orders enjoining future operations. Management believes that all of the Registrants' operations are in substantial compliance with current federal, state and local environmental standards. Environmental regulation can increase the cost of planning, design, initial installation and operation of OG&E's facilities. Management continues to evaluate its compliance with existing and proposed environmental legislation and regulations and implement appropriate environmental programs in a competitive market. CO 2 Emission Limits for Existing Generating Units On January 19, 2021, the U.S. Court of Appeals vacated the EPA's latest effort to adopt CO 2 emissions standards for existing coal-fired electric generating units, and the court remanded the matter to the EPA for further consideration. The EPA has indicated that administrative proceedings to respond to the U.S. Court of Appeals' remand in a new rulemaking action are ongoing but has not announced rulemaking details. The decision was based on the court's conclusion that the Clean Air Act does not require the EPA to limit the standards to measures that can be applied at and to an existing unit. On October 29, 2021, the U.S. Supreme Court granted petitions to review the decision; oral arguments before the Supreme Court are scheduled for February 28, 2022. The ultimate timing and impact of these standards on OG&E's operations cannot be determined with certainty at this time, although a requirement for significant reduction of CO 2 emissions from existing fossil-fuel-fired power plants ultimately could result in significant additional compliance costs that would affect the Registrants' future financial position, results of operations and cash flows if such costs are not recovered through regulated rates. Other

Rate Matters and Regulation

Rate Matters and Regulation	12 Months Ended
	Dec. 31, 2021
Regulated Operations [Abstract]
Rate Matters and Regulation	Rate Matters and Regulation Regulation and Rates OG&E's retail electric tariffs are regulated by the OCC in Oklahoma and by the APSC in Arkansas. The issuance of certain securities by OG&E is also regulated by the OCC and the APSC. OG&E's transmission activities, short-term borrowing authorization and accounting practices are subject to the jurisdiction of the FERC. The Secretary of the U.S. Department of Energy has jurisdiction over some of OG&E's facilities and operations. In 2021, 89 percent of OG&E's electric revenue was subject to the jurisdiction of the OCC, eight percent to the APSC and three percent to the FERC. The OCC and the APSC require that, among other things, (i) OGE Energy permits the OCC and the APSC access to the books and records of OGE Energy and its affiliates relating to transactions with OG&E; (ii) OGE Energy employ accounting and other procedures and controls to protect against subsidization of non-utility activities by OG&E's customers; and (iii) OGE Energy refrain from pledging OG&E assets or income for affiliate transactions. In addition, the FERC has access to the books and records of OGE Energy and its affiliates as the FERC deems relevant to costs incurred by OG&E or necessary or appropriate for the protection of utility customers with respect to the FERC jurisdictional rates. Completed Regulatory Matters APSC Proceedings Arkansas 2020 Formula Rate Plan Filing In October 2020, OG&E filed its third evaluation report under its Formula Rate Plan, and on January 28, 2021, OG&E entered into a non-unanimous settlement agreement with the APSC General Staff and the Office of the Arkansas Attorney General. The only non-signatory to the settlement agreement agreed not to oppose the settlement. The settlement agreement included a revenue increase of $6.7 million, which is the maximum amount statutorily allowed in this filing. Additionally, the settling parties did not object to OG&E's request for a finding that the Arkansas Series II grid modernization projects included in this filing are prudent in cost. On March 9, 2021, the APSC issued a final order approving the non-unanimous settlement agreement, and new rates became effective April 1, 2021. Disconnection Procedures Related to COVID-19 In September 2020, the APSC invited comments from all jurisdictional utilities and any other interested stakeholders on specific questions related to whether a moratorium on service terminations should be lifted and if so, how the resumption of disconnections should occur. The APSC also ordered utilities to submit a detailed "Transitional Plan" outlining how utilities proposed to reinstate routine service disconnection activities and collection of past due amounts once the moratorium was lifted. OG&E submitted its proposed Transitional Plan in October 2020. On February 8, 2021, the APSC announced a target date of May 3, 2021 to lift the moratorium on disconnections and specified certain conditions and requirements that utilities must meet before disconnections may resume. Such requirements include, among other things, immediate communication to customers, notice periods for disconnections and deferred payment arrangements. On March 26, 2021, the APSC confirmed the lifting of the moratorium on disconnections on May 3, 2021 and directed utilities to take specific steps prior to resuming disconnections. OG&E resumed disconnections on May 3, 2021. Arkansas Approval to Construct Out of State Generation On March 3, 2021, OG&E filed an application with the APSC to request approval to construct a 5 MW solar facility in Oklahoma. The APSC issued an order on April 6, 2021, finding OG&E's application in the public interest, conditioned on Arkansas customers being held harmless and not subject to cost recovery associated with the project. OG&E expects the costs associated with constructing this solar facility to be fully recovered in Oklahoma. Integrated Resource Plan OG&E has conducted technical conferences for stakeholder engagement on its draft triennial system-wide IRP and, in October 2021, issued its final 2021 IRP to the APSC. This 2021 IRP identified system-wide, cumulative capacity needs of 145, 183, 417 and 514 MWs in 2023, 2024, 2025 and 2026, respectively. OG&E has issued a request for proposals to identify options to fill the solar capacity needs identified within the 2021 IRP. OCC Proceedings Oklahoma Grid Enhancement Plan In February 2020, OG&E filed an application with the OCC for approval of a mechanism that allows for interim recovery of the costs associated with its grid enhancement plan. The plan includes approximately $800.0 million of strategic, data-driven investments, over five years, covering grid resiliency, grid automation, communication systems and technology platforms and applications. In November 2020, the OCC issued a final order approving a Joint Stipulation and Settlement Agreement that allows for interim recovery of OG&E's costs associated with its grid enhancement plan. The approved agreement included the following key terms: (i) cost recovery through a rider mechanism will be limited to projects placed in service in 2020 and 2021, capped at a revenue requirement of $7.0 million annually and only include communication, automation and technology systems projects; (ii) no operation and maintenance expense will be included in the rider mechanism; (iii) the rider mechanism will terminate by the issuance of a final order in OG&E's next general rate review or October 31, 2022, whichever occurs first; (iv) the rider mechanism rate of return will be capped at OG&E's current cost of capital; and (v) all cost recovery is subject to true-up and refund in OG&E's next general rate review. The rider mechanism became effective on February 1, 2021. OG&E reports to the OCC new projects completed each quarter, and the cost recovery factor is adjusted to include those projects after a stakeholder review. OG&E has submitted its report for projects that were placed in service through December 31, 2021. The cost recovery factors that include those projects will become effective on March 1, 2022. Any capital investment falling outside the criteria of the rider mechanism will be included in OG&E's next general rate review for recovery. Integrated Resource Plan OG&E has conducted technical conferences for stakeholder engagement on its draft triennial system-wide IRP and, in October 2021, issued its final 2021 IRP to the OCC. This 2021 IRP identified system-wide, cumulative capacity needs of 145, 183, 417 and 514 MWs in 2023, 2024, 2025 and 2026, respectively. OG&E has issued a request for proposals to identify options to fill the solar capacity needs identified within the 2021 IRP. Winter Storm Uri In February 2021, Winter Storm Uri resulted in record winter peak demand for electricity and extremely high natural gas and purchased power prices in OG&E's service territory. On February 24, 2021, OG&E submitted an application to the OCC outlining a two-step approach for regulatory treatment for the fuel and purchased power costs associated with Winter Storm Uri. The steps included: (i) an intra-year fuel clause increase to be effective April 1, 2021; and (ii) a request for regulatory asset treatment at OG&E's weighted average cost of capital for the remaining fuel and purchased power costs. On March 18, 2021, the OCC approved OG&E's filing to establish a regulatory asset. The approval allowed OG&E to create a regulatory asset for all deferred costs with an initial carrying charge based on the effective cost of the debt financing, until such time where the prudency of this event is evaluated, the amortization period is decided on and a long-term carry cost is established. In April 2021, Oklahoma enacted legislation to allow for the securitization of costs incurred during Winter Storm Uri. The new statute authorizes the OCC to issue a financing order for the issuance of securitization bonds after consideration of certain factors, including but not limited to, mitigated impacts and savings for customers through the use of ratepayer-backed securitization bonds as compared to traditional utility financing. The OCC must issue a financing order within 180 days after receiving all necessary information required by the statute. Under the statute, the ODFA is responsible for issuing the securitization bonds within two years from the date of the financing order. Carrying costs will be included at a rate and time determined by the OCC and continue until the bonds are issued. On April 26, 2021, OG&E filed an application pursuant to the Act seeking OCC approval to securitize its costs related to Winter Storm Uri and to receive an interim carrying charge on OG&E's regulatory asset balance at its weighted-average cost of capital for the period between April 2022 and the date when the securitized bonds are issued. On October 8, 2021, OG&E filed a settlement agreement between OG&E, the Public Utility Division Staff of the OCC, the Oklahoma Industrial Energy Consumers, the OG&E Shareholders Association and Walmart Inc. The settlement agreement was subject to approval by the OCC. The settling parties agreed the OCC should issue a financing order authorizing the securitization of $760.0 million, which includes estimated finance costs and is subject to change for carrying costs, any updates from the SPP settlement process and actual securitization issuance costs. The settling parties agree that OG&E's total extreme purchase costs (for natural gas and wholesale energy purchases) are currently estimated to be $748.9 million, of which it is agreed that $739.1 million should be deemed prudent. The OCC approved the settlement agreement in a final financing order on December 16, 2021. The ODFA has requested the Oklahoma Supreme Court to certify the proposed securitization bonds. OG&E is currently awaiting bond certification from the Oklahoma Supreme Court, which it expects to occur in the second quarter of 2022. OG&E is working with the ODFA to issue bonds consistent with the OCC's order. The securitization process is expected to be completed in mid-2022. 2020 Oklahoma Fuel Prudency On June 28, 2021, the Public Utility Division Staff filed their application initiating the review of the 2020 fuel adjustment clause and prudence review. On December 28, 2021, the OCC issued a final order finding OG&E's 2020 electric generation, purchased power and fuel procurement practices, policies, judgments and fuel purchase costs and expenses for 2020 were fair, just and reasonable. Demand Program Portfolio Filing Pursuant to OCC rules, OG&E is required to propose, implement and administer a portfolio of demand programs once every three years. On July 8, 2021, OG&E filed its proposed Demand Program Three Year Portfolio for the 2022 through 2024 program cycle, and the proposed program was approved by the OCC on February 1, 2022. Pending Regulatory Matters Various proceedings pending before state or federal regulatory agencies are described below. Unless stated otherwise, the Registrants cannot predict when the regulatory agency will act or what action the regulatory agency will take. The Registrants' financial results are dependent in part on timely and constructive decisions by the regulatory agencies that set OG&E's rates. FERC Proceedings Order for Sponsored Transmission Upgrades within SPP Under the SPP Open Access Transmission Tariff, costs of participant-funded, or "sponsored," transmission upgrades may be recovered from other SPP customers whose transmission service depends on capacity enabled by the upgrade. The SPP Open Access Transmission Tariff required the SPP to charge for these upgrades beginning in 2008, but the SPP had not been charging its customers for these upgrades due to information system limitations. However, the SPP had informed participants in the market that these charges would be forthcoming. In July 2016, the FERC granted the SPP's request to recover the charges not billed since 2008. The SPP subsequently billed OG&E for these charges and credited OG&E related to transmission upgrades that OG&E had sponsored, which resulted in OG&E being a net receiver of sponsored upgrade credits. The majority of these net credits were refunded to customers through OG&E's various rate riders that include SPP activity with the remaining amounts retained by OG&E. Several companies that were net payers of Z2 charges sought rehearing of the FERC's July 2016 order; however, in November 2017, the FERC denied the rehearing requests. In January 2018, one of the impacted companies appealed the FERC's decision to the U.S. Court of Appeals for the District of Columbia Circuit. In July 2018, that court granted a motion requested by the FERC that the case be remanded back to the FERC for further examination and proceedings. In February 2019, the FERC reversed its July 2016 order and November 2017 rehearing denial, ruled that the SPP violated its tariff to charge for the 2008 through 2015 period in 2016, held that the SPP tariff provision that prohibited those charges could not be waived and ordered the SPP to develop a plan to refund the payments but not to implement the refunds until further ordered to do so. In response, in April 2019, OG&E filed a request for rehearing with the FERC, and in May 2019, OG&E filed a FERC 206 complaint against the SPP, alleging that the SPP's forced unwinding of the revenue credit payments to OG&E would violate the provisions of the Sponsored Upgrade Agreement and of the applicable tariff. OG&E's filing requested that the FERC rule that the SPP is not entitled to seek refunds or in any other way seek to unwind the revenue credit payments it had paid to OG&E pursuant to the Sponsored Upgrade Agreement. The SPP's response to OG&E's filing agreed that OG&E should be entitled to keep its Z2 payments and argued that the SPP should not be held responsible for those payments if refunds are ordered. Further, the SPP has requested the FERC to negotiate a global settlement with all impacted parties, including other project sponsors who, like OG&E, have also filed complaints at FERC contending that the payments they have received cannot properly be unwound. In February 2020, the FERC denied OG&E's request for rehearing of its February 2019 order, denying the waiver and ruling that the SPP must seek refunds from project sponsors for Z2 payments for the 2008 through 2015 period and pay them back to transmission owners. The FERC also denied the SPP's request for a stay and for institution of settlement procedures. The FERC stated it would not institute settlement procedures unless parties on both sides of the matter requested them. The FERC did not rule on OG&E's complaint or the complaints of other project sponsors, or consider the SPP's refund plan. The FERC thus has not set any date for payment of refunds. In March 2020, OG&E petitioned the U.S. Court of Appeals for the District of Columbia Circuit for review of the FERC's order denying the waiver and requiring refunds. The court issued a decision on August 27, 2021, denying review and holding that the SPP was prohibited by the filed rate doctrine from imposing Z2 charges during the 2008 through 2015 historical period. The court further held that the FERC reasonably exercised its remedial authority to order the SPP to refund the retroactive upgrade charge. The court did not direct a time frame or procedures for the SPP to implement refunds. OG&E and the SPP filed a petition for rehearing of the court's decision, which was denied on October 29, 2021. The court returned the matter to the FERC for action in accordance with its opinion on November 8, 2021. If the FERC proceeds to order refunds in full, OG&E estimates it would be required to refund $13.0 million, which is net of amounts paid to other utilities for upgrades and would be subject to interest at the FERC-approved rate. The SPP has stated in filings it made with the FERC while the appeal was pending that there are considerable complexities in implementing the refunds that will have to be resolved before they can be paid. Payment of refunds would shift recovery of these upgrade credits to future periods. The SPP filed an update on January 4, 2022 confirming that administering refunds would be complex and could take years unless the SPP is allowed to make certain simplifying assumptions. It also urged that all pending complaint proceedings, including four complaints against the SPP, be resolved before the refund process is ordered to begin. Of the $13.0 million, the Registrants would be impacted by $5.0 million in expense that initially benefited the Registrants in 2016, and OG&E customers would incur a net impact of $8.0 million in expense through rider mechanisms or the FERC formula rate. As of December 31, 2021, the Registrants have reserved $13.0 million plus estimated interest for a potential refund. In January 2020, the FERC acted on an SPP proposal to eliminate Attachment Z2 revenue crediting and replace it with a different rate mechanism that would provide project sponsors, such as OG&E, the same level of recovery, and rejected the proposal to the extent it would limit recovery to the amount of the upgrade sponsor's directly assigned upgrade costs with interest. The SPP resubmitted a proposal in April 2020 without this limited recovery, and with the alternative rate mechanism, and the FERC approved it in June 2020, effective July 1, 2020. No party sought rehearing of the order, and it is now final. This order would only prospectively impact OG&E and its recovery of any future upgrade costs that it may incur as a project sponsor subsequent to July 2020. All of the existing projects that are eligible to receive revenue credits under Attachment Z2, which includes the $13.0 million at issue in OG&E's appeal as discussed above, will continue to do so. Incentive Adders for Transmission Rates The FERC issued a NOPR on March 20, 2020, and issued a supplemental NOPR on April 15, 2021, proposing to update its transmission incentives policy. Among other things, the NOPR proposes (i) the current 50-basis point return on equity adder for RTO/ISO participation would be applicable only to transmitting utilities that join an RTO/ISO, and this incentive would only apply for the first three years in which the utility is an RTO/ISO member and (ii) transmitting utilities that have been members of an RTO/ISO for three years or more, such as OG&E, would be required to make a compliance filing to remove the existing return on equity adder from their rates. OG&E is currently evaluating the potential impacts of this proposed rule. Currently, there is no specific deadline for the FERC to take further action, and it is unknown whether the FERC will address the RTO participation adder individually or as part of a larger order on transmission incentives. APSC Proceedings Winter Storm Uri In February 2021, Winter Storm Uri resulted in record winter peak demand for electricity and extremely high natural gas and purchased power prices in OG&E's service territory. On April 1, 2021, OG&E filed with the APSC a Motion for Authority to Establish Special Regulatory Treatment within the Energy Cost Recovery Rider to Defer Extraordinary Fuel Costs Incurred Due to Winter Storm Uri. More specifically, OG&E's motion sought approval to defer, amortize and recover the extraordinary fuel costs over a ten-year period with a carrying charge of OG&E's pre-tax rate of return of 6.60 percent, through a special factor within OG&E's Energy Cost Recovery Rider beginning with the first billing cycle of May 2021. On April 13, 2021, the APSC issued an order allowing OG&E interim recovery at an interest rate equal to the customer deposit interest rate, which is currently 0.8 percent, over a period of ten years beginning with the first billing cycle of May 2021. Recovery is subject to a true-up after the APSC determines the appropriate allocation, length of recovery and carrying charge. On May 4, 2021, OG&E filed testimony further supporting its 10-year amortization period and a carrying charge of OG&E's pre-tax rate of return of 6.60 percent. In April 2021, Arkansas enacted legislation to amend its storm recovery securitization statute to allow for both electric and gas utilities to recover through securitization extraordinary natural gas, fuel and purchased power costs caused by storms. The amended statute authorizes the APSC to issue a financing order for the issuance of securitization bonds upon a finding it is reasonably expected to lower overall costs or mitigate rate impacts as compared with traditional utility financing. Upon the initiation of a securitization application, the APSC has 135 days to issue an order. The requesting utility has two years from the date of the financing order to issue the securitization bonds. The amended statute allows carrying costs at a utility's weighted average cost of capital from the date of when the costs were incurred until the date when bonds are ultimately issued. On May 20, 2021, OG&E filed a motion for suspension of procedural schedule, which the APSC approved, to investigate and evaluate the potential securitization recovery of the Arkansas jurisdictional portion of the Winter Storm Uri costs. OG&E intends to apply for securitization in early 2022 if it is deemed to strike the right balance between protecting the credit strength of OG&E and providing customer savings. As of December 31, 2021, OG&E has deferred $88.9 million to a regulatory asset, as indicated in Note 1. Arkansas 2021 Formula Rate Plan Filing On October 1, 2021, OG&E filed its fourth evaluation report under its Formula Rate Plan, and on February 1, 2022, OG&E, the APSC General Staff and the Office of the Arkansas Attorney General filed a non-unanimous joint settlement agreement, which includes an annual electric revenue increase of $4.2 million. The only non-signatory to the settlement agreement has agreed not to oppose the settlement. The settlement agreement is subject to approval by the APSC. A final order is expected from the APSC in March 2022, and new rates will be effective April 1, 2022. On October 1, 2021, OG&E also filed a request to extend its Formula Rate Plan Rider for an additional five years. A hearing on the merits was held on February 23, 2022, and OG&E expects a decision from the APSC in April 2022. OCC Proceedings Oklahoma Retail Electric Supplier Certified Territory Act Causes Several rural electric cooperative electricity suppliers have filed complaints with the OCC alleging that OG&E has violated the Oklahoma Retail Electric Supplier Certified Territory Act. OG&E believes it is lawfully serving customers specifically exempted from this act and has presented evidence and testimony to the OCC supporting its position. There have been five complaint cases initiated at the OCC, and the OCC has issued decisions on each of them. The OCC ruled in favor of the electric cooperatives in three of those cases and ruled in favor of OG&E in two of those cases. All five of those cases have been appealed to the Oklahoma Supreme Court, where they have been made companion cases but will be individually briefed and have individual final decisions. If the Oklahoma Supreme Court ultimately were to find that some or all of the customers being served are not exempted from the Oklahoma Retail Electric Supplier Certified Territory Act, OG&E would have to evaluate the recoverability of some plant investments made to serve these customers. The total amount of OG&E's plant investments made to serve the customers in all five cases is approximately $28.0 million , of which $11.7 million applies to the three cases where the OCC ruled in favor of the electric cooperatives. In addition to the evaluation of the recoverability of the investments, OG&E may also be required to reimburse certified territory suppliers for an amount of lost revenue. The amount of such lost revenue would depend on how the OCC calculates the revenue requirement but could range from approximately $28.9 million to $39.3 million for all five cases, of which $2.9 million to $4.5 million would apply to the three cases where the OCC ruled in favor of the electric cooperatives. 2021 Oklahoma General Rate Review On December 30, 2021, OG&E filed a general rate review in Oklahoma seeking a rate increase of $163.5 million and a 10.2 percent return on equity based on a common equity percentage of 53.37 percent. The rate review includes recovery of $1.2 billion of capital investment since the last general rate review. A hearing on the merits is expected to be held toward the end of the second quarter of 2022.

Schedule II

Schedule II	9 Months Ended
	Sep. 30, 2021
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
SEC Schedule, 12-09, Schedule of Valuation and Qualifying Accounts Disclosure [Text Block]	SCHEDULE II - Valuation and Qualifying Accounts Additions Description Balance at Beginning of Period Charged to Costs and Expenses Deductions (A) Balance at End of Period (In millions) Balance at December 31, 2019 Reserve for Uncollectible Accounts $ 1.7 $ 2.2 $ 2.4 $ 1.5 Balance at December 31, 2020 Reserve for Uncollectible Accounts $ 1.5 $ 3.0 $ 1.9 $ 2.6 Balance at December 31, 2021 Reserve for Uncollectible Accounts $ 2.6 $ 3.2 $ 3.4 $ 2.4

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Consolidation, Policy [Policy Text Block]	Organization OGE Energy is a holding company with investments in energy and energy services providers offering physical delivery and related services for electricity in Oklahoma and western Arkansas and natural gas, crude oil and NGLs across the U.S. OGE Energy conducts these activities through two business segments: (i) electric utility and (ii) natural gas midstream operations. The accounts of OGE Energy and its wholly-owned subsidiaries, including OG&E, are included in OGE Energy's consolidated financial statements. All intercompany transactions and balances are eliminated in such consolidation. OGE Energy generally uses the equity method of accounting for investments where its ownership interest is between 20 percent and 50 percent and it lacks the power to direct activities that most significantly impact economic performance. Electric Utility Operations . OGE Energy's electric utility operations are conducted through OG&E, which generates, transmits, distributes and sells electric energy in Oklahoma and western Arkansas. OG&E's rates are subject to regulation by the OCC, the APSC and the FERC. OG&E was incorporated in 1902 under the laws of the Oklahoma Territory and is a wholly-owned subsidiary of OGE Energy. OG&E is the largest electric utility in Oklahoma, and its franchised service territory includes Fort Smith, Arkansas and the surrounding communities. OG&E sold its retail natural gas business in 1928 and is no longer engaged in the natural gas distribution business. Natural Gas Midstream Operations. In February 2021, Enable entered into a definitive merger agreement with Energy Transfer, pursuant to which all outstanding common units of Enable were to be acquired by Energy Transfer in an all-equity transaction. The transaction closed on December 2, 2021, and under the terms of the merger agreement, OGE Energy received 95,389,721 common units of Energy Transfer for OGE Energy’s 110,982,805 common units of Enable. As part of the transaction, Energy Transfer also acquired the general partner interests of Enable from OGE Energy and CenterPoint for cash consideration. Upon the transaction closing, OGE Energy owned approximately three percent of Energy Transfer's outstanding limited partner units in lieu of the 25.5 percent interest in Enable that it previously owned. For periods prior to December 2, 2021, OGE Energy's natural gas midstream operations segment represented OGE Energy's investment in Enable, which OGE Energy accounted for as an equity method investment. Formed in 2013, Enable was primarily engaged in the business of gathering, processing, transporting and storing natural gas primarily in the south central U.S. For further discussion regarding Enable's business, see OGE Energy's 2020 Form 10-K . Upon the closing of the Energy Transfer and Enable merger, OGE Energy's natural gas midstream operations segment represents OGE Energy's investment in Energy Transfer's equity securities and legacy Enable seconded employee pension and postretirement costs. The investment in Energy Transfer's equity securities is held through wholly-owned subsidiaries and ultimately OGE Holdings. At December 31, 2021, OGE energy owned 95.4 million, or approximately three percent, of Energy Transfer's limited partner units. OGE Energy does not have significant influence over Energy Transfer, as OGE Energy does not own general partner units in or have board representation at Energy Transfer. As such, OGE Energy accounts for its investment in Energy Transfer as an investment in equity securities, as further discussed under "Investment in Equity Securities of Energy Transfer" below. OGE Energy intends to exit the midstream segment in a prudent manner.
Public Utilities, Policy [Policy Text Block]	Accounting Records The accounting records of OG&E are maintained in accordance with the Uniform System of Accounts prescribed by the FERC and adopted by the OCC and the APSC. Additionally, OG&E, as a regulated utility, is subject to accounting principles for certain types of rate-regulated activities, which provide that certain incurred costs that would otherwise be charged to expense can be deferred as regulatory assets, based on the expected recovery from customers in future rates. Likewise, certain actual or anticipated credits that would otherwise reduce expense can be deferred as regulatory liabilities, based on the expected flowback to customers in future rates. Management's expected recovery of deferred costs and flowback of deferred credits generally results from specific decisions by regulators granting such ratemaking treatment. OG&E records certain incurred costs and obligations as regulatory assets or liabilities if, based on regulatory orders or other available evidence, it is probable that the costs or obligations will be included in amounts allowable for recovery or refund in future rates.
Use of Estimates, Policy [Policy Text Block]	Use of Estimates
Cash and Cash Equivalents, Policy [Policy Text Block]	Cash and Cash Equivalents
Allowance for Uncollectible Accounts Receivable, Policy	Customer balances are generally written off if not collected within six months after the final billing date. The allowance for uncollectible accounts receivable for OG&E is generally calculated by multiplying the last six months of electric revenue by the provision rate, which is based on a 12-month historical average of actual balances written off and is adjusted for current conditions and supportable forecasts as necessary. To the extent the historical collection rates, when incorporating forecasted conditions, are not representative of future collections, there could be an effect on the amount of uncollectible expense recognized, such as in response to COVID-19 impacts. Also, a portion of the uncollectible provision related to fuel within the Oklahoma jurisdiction is being recovered through the fuel adjustment clause. The allowance for uncollectible accounts receivable is a reduction to Accounts Receivable in the balance sheets and is included in Other Operation and Maintenance Expense in the statements of income. The allowance for uncollectible accounts receivable was $2.4 million and $2.6 million at December 31, 2021 and 2020, respectively. New business customers are required to provide a security deposit in the form of cash, bond or irrevocable letter of credit that is refunded when the account is closed. New residential customers whose outside credit scores indicate an elevated risk are required to provide a security deposit that is refunded based on customer protection rules defined by the OCC and the APSC. The payment behavior of all existing customers is continuously monitored, and, if the payment behavior indicates sufficient risk within the meaning of the applicable utility regulation, customers will be required to provide a security deposit.
Inventory, Policy [Policy Text Block]	Fuel Inventories Fuel inventories for the generation of electricity consist of coal, natural gas and oil. OG&E uses the weighted-average cost method of accounting for inventory that is physically added to or withdrawn from storage or stockpiles. The amount of fuel inventory was $40.6 million and $36.5 million at December 31, 2021 and 2020, respectively.
Property, Plant and Equipment, Policy [Policy Text Block]	Property, Plant and Equipment
Depreciation and Amortization, Policy [Policy Text Block]	Depreciation and Amortization The provision for depreciation, which was 2.6 percent of the average depreciable utility plant for both 2021 and 2020, is calculated using the straight-line method over the estimated service life of the utility assets. Depreciation is provided at the unit level for production plant and at the account or sub-account level for all other plant and is based on the average life group method. In 2022, the provision for depreciation is projected to be 2.6 percent of the average depreciable utility plant. Amortization of intangible assets is calculated using the straight-line method. Of the remaining amortizable intangible plant balance at December 31, 2021, 99.1 percent will be amortized over 10.4 years with the remaining 0.9 percent of the intangible plant balance at December 31, 2021 being amortized over 23.7 years. Amortization of plant acquisition adjustments is provided on a straight-line basis over the estimated remaining service life of the acquired assets. Plant acquisition adjustments include $148.3 million for the Redbud Plant, which is being amortized over a 27 year life, and $3.3 million for certain transmission substation facilities in OG&E's service territory, which is being amortized over a 37 to 59 year period.
Equity Method Investments [Policy Text Block]	Investment in Unconsolidated Affiliates Prior to December 2, 2021, OGE Energy's investment in Enable was considered to be a variable interest entity because the owners of the equity at risk in the entity had disproportionate voting rights in relation to their obligations to absorb the entity's expected losses or to receive its expected residual returns. However, OGE Energy was not considered the primary beneficiary of Enable since it did not have the power to direct the activities of Enable that are considered most significant to the economic performance of Enable; therefore, OGE Energy accounted for its investment in Enable using the equity method of accounting. Under the equity method, the investment was adjusted each period for contributions made, distributions received and OGE Energy's share of the investee's comprehensive income as adjusted for basis differences. OGE Energy considered distributions received from Enable which did not exceed cumulative equity in earnings subsequent to the date of investment to be a return on investment and are classified as operating activities in the statements of cash flows. OGE Energy considered distributions received from Enable in excess of cumulative equity in earnings subsequent to the date of investment to be a return of investment and are classified as investing activities in the statements of cash flows.
Asset Retirement Obligation [Policy Text Block]	Asset Retirement ObligationsOG&E has asset retirement obligations primarily associated with the removal of company-owned wind turbines on leased land, as well as the removal of asbestos from certain power generating stations. OG&E has recorded asset retirement obligations that are being accreted over their respective lives ranging from five to 68 years. Asset retirement obligations are included in Other Deferred Credits in the Registrants' balance sheets.
Allowance for Funds Used During Construction, Policy [Policy Text Block]	Allowance for Funds Used During Construction
Collection of Sales Tax, Policy [Policy Text Block]	Collection of Sales Tax
Revenue Recognition, Policy [Policy Text Block]	Revenue Recognition General OG&E recognizes revenue from electric sales when power is delivered to customers. The performance obligation to deliver electricity is generally created and satisfied simultaneously, and the provisions of the regulatory-approved tariff determine the charges OG&E may bill the customer, payment due date and other pertinent rights and obligations of both parties. OG&E measures its customers' metered usage and sends bills to its customers throughout each month. As a result, there is a significant amount of customers' electricity consumption that has not been billed at the end of each month. OG&E accrues an estimate of the revenues for electric sales delivered since the latest billings. Unbilled revenue is presented in Accrued Unbilled Revenues in the balance sheets and in Revenues from Contracts with Customers in the statements of income based on estimates of usage and prices during the period. The estimates that management uses in this calculation could vary from the actual amounts to be paid by customers. Integrated Market and Transmission OG&E currently owns and operates transmission and generation facilities as part of a vertically integrated utility. OG&E is a member of the SPP regional transmission organization and has transferred operational authority, but not ownership, of OG&E's transmission facilities to the SPP. The SPP has implemented FERC-approved regional day-ahead and real-time markets for energy and operating services, as well as associated transmission congestion rights. Collectively, the three markets operate together under the global name, SPP Integrated Marketplace. OG&E represents owned and contracted generation assets and customer load in the SPP Integrated Marketplace for the sole benefit of its customers. OG&E has not participated in the SPP Integrated Marketplace for any speculative trading activities. OG&E records the SPP Integrated Marketplace transactions as sales or purchases per FERC Order 668, which requires that purchases and sales be recorded on a net basis for each settlement period of the SPP Integrated Marketplace. Purchases and sales are based on the fixed transaction price determined by the market at the time of the purchase or sale and the MWh quantity purchased or sold. These results are reported as Revenues from Contracts with Customers or Fuel, Purchased Power and Direct Transmission Expense in the statements of income. OG&E revenues, expenses, assets and liabilities may be adversely affected by changes in the organization, operating and regulation by the FERC or the SPP. OG&E's transmission revenues are generated by the use of OG&E's transmission network by the SPP, which operates the network, on behalf of other transmission owners. OG&E recognizes revenue on the sale of transmission service to its customers over time as the service is provided in the amount OG&E has a right to invoice. Transmission service to the SPP is billed monthly based on a fixed transaction price determined by OG&E's FERC-approved formula transmission rates along with other SPP-specific charges and the megawatt quantity reserved. Other Revenues Other Revenues in the statements of income is comprised of certain rider revenue that includes alternative revenue measures as defined in ASC 980, "Regulated Operations," which details two types of alternative revenue programs. The first type adjusts billings for the effects of weather abnormalities or broad external factors or to compensate OG&E for demand-side
Fuel Adjustment Clauses, Policy [Policy Text Block]	Fuel Adjustment Clauses The actual cost of fuel used in electric generation and certain purchased power costs are generally recoverable from OG&E's customers through fuel adjustment clauses. The fuel adjustment clauses are subject to periodic review by the OCC and the APSC. Actual fuel costs from Winter Storm Uri are recoverable from OG&E's customers through securitization of regulatory assets. Both the OCC and the APSC allowed OG&E to create a regulatory asset for each jurisdictional portion of all deferred costs, as further discussed above within "Accounting Records." For additional information on Oklahoma securitization, see Note 16.
Lessee, Leases	LeasesThe Registrants evaluate all contracts under ASC 842 to determine if the contract is or contains a lease and to determine classification as an operating or finance lease. If a lease is identified, the Registrants recognize a right-of-use asset and a lease liability in their balance sheets. The Registrants recognize and measure a lease liability when they conclude the contract contains an identified asset that the Registrants control through having the right to obtain substantially all of the economic benefits and the right to direct the use of the identified asset. The liability is equal to the present value of lease payments, and the asset is based on the liability, subject to adjustment, such as for initial direct costs. Further, the Registrants utilize an incremental borrowing rate for purposes of measuring lease liabilities, if the discount rate is not implicit in the lease. To calculate the incremental borrowing rate, the Registrants start with a current pricing report for their senior unsecured notes, which indicates rates for periods reflective of the lease term, and adjust for the effects of collateral to arrive at the secured incremental borrowing rate. As permitted by ASC 842, the Registrants made an accounting policy election to not apply the balance sheet recognition requirements to short-term leases and to not separate lease components from non-lease components when recognizing and measuring lease liabilities. For income statement purposes, the Registrants record operating lease expense on a straight-line basis.
Income Taxes, Policy [Policy Text Block]	Income Taxes OGE Energy files consolidated income tax returns in the U.S. federal jurisdiction and various state jurisdictions. OG&E is a part of the consolidated tax return of OGE Energy. Income taxes are generally allocated to each company in the affiliated group, including OG&E, based on its stand-alone taxable income or loss. Federal investment tax credits previously claimed on electric utility property have been deferred and will be amortized to income over the life of the related property. The Registrants use the asset and liability method of accounting for income taxes. Under this method, a deferred tax asset or liability is recognized for the estimated future tax effects attributable to temporary differences between the financial statement basis and the tax basis of assets and liabilities as well as tax credit carry forwards and net operating loss carry forwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in the period of the change. The Registrants recognize interest related to unrecognized tax benefits in Interest Expense and recognize penalties in Other Expense in the statements of income.
Accrued Vacation, Policy [Policy Text Block]	Accrued Vacation The Registrants accrue vacation pay monthly by establishing a liability for vacation earned. Vacation may be taken as earned and is charged against the liability. At the end of each year, the liability represents the amount of vacation earned but not taken.
Environmental Costs, Policy [Policy Text Block]	Accruals for environmental costs are recognized when it is probable that a liability has been incurred and the amount of the liability can be reasonably estimated. Costs are charged to expense or deferred as a regulatory asset based on expected recovery from customers in future rates, if they relate to the remediation of conditions caused by past operations or if they are not expected to mitigate or prevent contamination from future operations. Where environmental expenditures relate to facilities currently in use, such as pollution control equipment, the costs may be capitalized and depreciated over the future service periods. Estimated remediation costs are recorded at undiscounted amounts, independent of any insurance or rate recovery, based on prior experience, assessments and current technology. Accrued obligations are regularly adjusted as environmental assessments and estimates are revised and remediation efforts proceed. For sites where OG&E has been designated as one of several potentially responsible parties, the amount accrued represents OG&E's estimated share of the cost. OG&E had $25.8 million and $25.0 million in accrued environmental liabilities at December 31, 2021 and 2020, respectively, which are included in OG&E's asset retirement obligations.
Fair Value of Financial Instruments, Policy [Policy Text Block]	Fair Value Measurements The classification of the Registrants' fair value measurements requires judgment regarding the degree to which market data is observable or corroborated by observable market data. GAAP establishes a fair value hierarchy that prioritizes the inputs used to measure fair value based on observable and unobservable data. The hierarchy categorizes the inputs into three levels, with the highest priority given to quoted prices in active markets for identical unrestricted assets or liabilities (Level 1) and the lowest priority given to unobservable inputs (Level 3). Financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The three levels defined in the fair value hierarchy are as follows: Level 1 inputs are quoted prices in active markets for identical unrestricted assets or liabilities that are accessible at the measurement date. Level 2 inputs are inputs other than quoted prices in active markets included within Level 1 that are either directly or indirectly observable at the reporting date for the asset or liability for substantially the full term of the asset or liability. Level 2 inputs include quoted prices for similar assets or liabilities in active markets and quoted prices for identical or similar assets or liabilities in markets that are not active. Level 3 inputs are prices or valuation techniques for the asset or liability that require inputs that are both significant to the fair value measurement and unobservable (i.e., supported by little or no market activity). Unobservable inputs reflect the reporting entity's own assumptions about the assumptions that market participants would use in pricing the asset or liability (including assumptions about risk).
Share-based Compensation, Option and Incentive Plans, Policy [Policy Text Block]	Performance Units Under the Stock Incentive Plan, OGE Energy has issued performance units which represent the value of one share of OGE Energy's common stock. The performance units provide for accelerated vesting if there is a change in control (as defined in the Stock Incentive Plan). Each performance unit is subject to forfeiture if the recipient terminates employment with OGE Energy or a subsidiary prior to the end of the primarily three-year award cycle for any reason other than death, disability or retirement. In the event of death, disability or retirement, a participant will receive a prorated payment based on such participant's number of full months of service during the award cycle, further adjusted based on the achievement of the performance goals during the award cycle. The Registrants estimate expected forfeitures in accounting for performance unit compensation expense. The performance units granted based on total shareholder return are contingently awarded and will be payable in shares of OGE Energy's common stock subject to the condition that the number of performance units, if any, earned by the employees upon the expiration of a primarily three-year award cycle (i.e., three-year cliff vesting period) is dependent on OGE Energy's total shareholder return ranking relative to a peer group of companies. The performance units granted based on earnings per share were contingently awarded and will be payable in shares of OGE Energy's common stock based on OGE Energy's earnings per share growth over a primarily three-year award cycle (i.e., three-year cliff vesting period) compared to a target set at the time of the grant by the Compensation Committee of OGE Energy's Board of Directors. All of these performance units are classified as equity in the balance sheets. If there is no or only a partial payout for the performance units at the end of the award cycle, the unearned performance units are cancelled. Payout requires approval of the Compensation Committee of OGE Energy's Board of Directors. Payouts, if any, are all made in common stock and are considered made when the payout is approved by the Compensation Committee. Performance Units – Total Shareholder Return Restricted Stock Units Under the Stock Incentive Plan, OGE Energy has issued restricted stock units to certain existing non-officer employees as well as other executives upon hire to attract and retain individuals to be competitive in the marketplace, and as of the 2019 grant cycle, restricted stock units are granted in lieu of performance units based on earnings per share. The restricted stock units vest primarily in a three-year award cycle (i.e., three-year cliff vesting period). Prior to vesting, each restricted stock unit is subject to forfeiture if the recipient ceases to render substantial services to OGE Energy or a subsidiary. These restricted stock units may not be sold, assigned, transferred or pledged and are subject to a risk of forfeiture. The fair value of the restricted stock units was based on the closing market price of OGE Energy's common stock on the grant date. Compensation expense for the restricted stock units is a fixed amount determined at the grant date fair value and is recognized as services are rendered by employees over a primarily three-year vesting period. Also, for those restricted stock units that vest in one-third annual increments over a three-year cycle, OGE Energy treats its restricted stock units as multiple separate awards by recording compensation expense separately for each tranche whereby a substantial portion of the expense is recognized in the earlier years in the requisite service period.
Earnings Per Share, Policy [Policy Text Block]	Earnings (Loss) Per Share
Pension and Other Postretirement Plans, Policy [Policy Text Block]	Pension Plan and Restoration of Retirement Income Plan It is OGE Energy's policy to fund the Pension Plan on a current basis based on the net periodic pension expense as determined by OGE Energy's actuarial consultants. Such contributions are intended to provide not only for benefits attributed to service to date but also for those expected to be earned in the future. OGE Energy made a $40.0 million and $20.0 million contribution to its Pension Plan in 2021 and 2020, of which $30.0 million and $10.0 million was attributed to OG&E in 2021 and 2020, respectively. OGE Energy does not expect it will need to make any contributions to the Pension Plan in 2022. Any contribution to the Pension Plan during 2022 would be a discretionary contribution, anticipated to be in the form of cash, and is not required to satisfy the minimum regulatory funding requirement specified by the Employee Retirement Income Security Act of 1974, as amended. OGE Energy could be required to make additional contributions if the value of its pension trust and postretirement benefit plan trust assets are adversely impacted by a major market disruption in the future. OGE Energy provides a Restoration of Retirement Income Plan to those participants in OGE Energy's Pension Plan whose benefits are subject to certain limitations of the Code. Participants in the Restoration of Retirement Income Plan receive the same benefits that they would have received under OGE Energy's Pension Plan in the absence of limitations imposed by the federal tax laws. The Restoration of Retirement Income Plan is intended to be an unfunded plan. OG&E's employees participate in OGE Energy's Pension Plan and Restoration of Retirement Income Plan. Postretirement Benefit Plans In addition to providing pension benefits, OGE Energy provides certain medical and life insurance benefits for eligible retired members. Regular, full-time, active employees hired prior to February 1, 2000 whose age and years of credited service total or exceed 80 or have attained at least age 55 with 10 or more years of service at the time of retirement are entitled to postretirement medical benefits, while employees hired on or after February 1, 2000 are not entitled to postretirement medical benefits. Eligible retirees must contribute such amount as OGE Energy specifies from time to time toward the cost of coverage for postretirement benefits. The benefits are subject to deductibles, co-payment provisions and other limitations. OG&E charges postretirement benefit costs to expense and includes an annual amount as a component of the cost-of-service in future ratemaking proceedings.
Postemployment Benefit Plans, Policy [Policy Text Block]	Post-Employment Benefit Plan Disabled employees receiving benefits from OGE Energy's Group Long-Term Disability Plan are entitled to continue participating in OGE Energy's Medical Plan along with their dependents. The post-employment benefit obligation represents the actuarial present value of estimated future medical benefits that are attributed to employee service rendered prior to the date as of which such information is presented. The obligation also includes future medical benefits expected to be paid to current employees participating in the Group Long-Term Disability Plan and their dependents, as defined in OGE Energy's Medical Plan.
Plan Investments, Policies and Strategies, Policy [Policy Text Block]	Pension Plan Investments, Policies and Strategies The Pension Plan assets are held in a trust which follows an investment policy and strategy designed to reduce the funded status volatility of the Plan by utilizing liability driven investing. The purpose of liability-driven investing is to structure the asset portfolio to more closely resemble the pension liability and thereby more effectively hedge against changes in the liability. The investment policy follows a glide path approach that shifts a higher portfolio weighting to fixed income as the Plan's funded status increases. The following table presents the targeted fixed income and equity allocations at different funded status levels. Projected Benefit Obligation Funded Status Thresholds <90% 95% 100% 105% 110% 115% 120% Fixed income 50% 58% 65% 73% 80% 85% 90% Equity 50% 42% 35% 27% 20% 15% 10% Total 100% 100% 100% 100% 100% 100% 100% Within the portfolio's overall allocation to equities, the funds are allocated according to the guidelines in the following table. Asset Class Target Allocation Minimum Maximum Domestic Large Cap Equity 40% 35% 60% Domestic Mid-Cap Equity 15% 5% 25% Domestic Small-Cap Equity 25% 5% 30% International Equity 20% 10% 30% OGE Energy has retained an investment consultant responsible for the general investment oversight, analysis, monitoring investment guideline compliance and providing quarterly reports to certain of the Registrants' members and OGE Energy's Investment Committee. The various investment managers used by the trust operate within the general operating objectives as established in the investment policy and within the specific guidelines established for each investment manager's respective portfolio. The portfolio is rebalanced at least on an annual basis to bring the asset allocations of various managers in line with the target asset allocation listed above. More frequent rebalancing may occur if there are dramatic price movements in the financial markets which may cause the trust's exposure to any asset class to exceed or fall below the established allowable guidelines. To evaluate the progress of the portfolio, investment performance is reviewed quarterly. It is, however, expected that performance goals will be met over a full market cycle, normally defined as a three- to five-year period. Analysis of performance is within the context of the prevailing investment environment and the advisors' investment style. The goal of the trust is to provide a rate of return consistently from three percent to five percent over the rate of inflation (as measured by the national Consumer Price Index) on a fee adjusted basis over a typical market cycle of no less than three years and no more than five years. Each investment manager is expected to outperform its respective benchmark. The following table presents a list of each asset class utilized with appropriate comparative benchmark(s) each manager is evaluated against and the focus of the asset class. Asset Class Comparative Benchmark(s) Focus of Asset Class Active Duration Fixed Income (A)(B) Bloomberg Barclays Aggregate l Maximize risk-adjusted performance while providing long bond exposure managed according to the manager's forecast on interest rates. l All invested assets must reach at or above Baa3 or BBB- investment grade. l Limited five percent exposure to any single issuer, except the U.S. Government or affiliates. Long Duration Fixed Income (A)(B) Duration blended Barclays Long Government/Credit & Barclays Universal l Maximize risk-adjusted performance. l At least 75 percent of invested assets much reach at or above Baaa3 or BBB- investment grade. l Limited five percent exposure to any single issuer, except the U.S. Government or affiliates. l May invest up to 10 percent of the market value in convertible bonds as long as quality guidelines are met. l May invest up to 15 percent of the market value in private placement, including 144A securities with or without registration rights and allow for futures to be traded in the portfolio. Equity Index (B)(C) Standard & Poor's 500 Index l Focus on replicating the performance of the S&P 500 Index. Mid-Cap Equity (B)(C) Russell Midcap Index l Focus on undervalued stocks expected to earn average return and pay out higher than average dividends. l Invest in companies with market capitalizations lower than average company on public exchanges: l Price/earnings ratio at or near referenced index; l Small dividend yield and return on equity at or near referenced index; and l Earnings per share growth rate at or near referenced index. Small-Cap Equity (B)(C) Russell 2000 Index International Equity (D) Morgan Stanley Capital International ACWI ex-U.S. l Invest in non-dollar denominated equity securities. l Diversify the overall trust investments. (A) Investment grades are by Moody's Investors Service, S&P Global Ratings or Fitch Ratings. (B) The purchase of any of OGE Energy's equity, debt or other securities is prohibited. (C) No more than five percent can be invested in any one stock at the time of purchase and no more than 10 percent after accounting for price appreciation. Options or financial futures may not be purchased unless prior approval from OGE Energy's Investment Committee is received. The purchase of securities on margin, securities lending, private placement purchases and venture capital purchases are prohibited. The aggregate positions in any company may not exceed one percent of the fair market value of its outstanding stock. (D) The manager of this asset class is required to operate under certain restrictions including regional constraints, diversification requirements and percentage of U.S. securities. All securities are freely traded on a recognized stock exchange, and there are no over-the-counter derivatives. The following investment categories are excluded: options (other than traded currency options), commodities, futures (other than currency futures or currency hedging), short sales/margin purchases, private placements, unlisted securities and real estate (but not real estate shares).
Pension and Other Postretirement Plans, Nonpension Benefits, Policy [Policy Text Block]	401(k) Plan OGE Energy provides a 401(k) Plan, and each regular full-time employee of OGE Energy or a participating affiliate is eligible to participate in the 401(k) Plan immediately upon hire. All other employees of OGE Energy or a participating affiliate are eligible to become participants in the 401(k) Plan after completing one year of service as defined in the 401(k) Plan. Participants may contribute each pay period any whole percentage between two percent and 19 percent of their compensation, as defined in the 401(k) Plan, for that pay period. Participants who have reached age 50 before the close of a year are allowed to make additional contributions referred to as "Catch-Up Contributions," subject to certain limitations of the Code. Participants may designate, at their discretion, all or any portion of their contributions as: (i) a before-tax contribution under Section 401(k) of the Code subject to the limitations thereof, (ii) a contribution made on a non-Roth after-tax basis or (iii) a Roth contribution. The 401(k) Plan also includes an eligible automatic contribution arrangement and provides for a qualified default investment alternative consistent with the U.S. Department of Labor regulations. Participants may elect, in accordance with the 401(k) Plan procedures, to have their future salary deferral rate to be automatically increased annually on a date and in an amount as specified by the participant in such election. For employees hired or rehired on or after December 1, 2009, OGE Energy contributes to the 401(k) Plan, on behalf of each participant, 200 percent of the participant's contributions up to five percent of compensation. No OGE Energy contributions are made with respect to a participant's Catch-Up Contributions, rollover contributions or with respect to a participant's contributions based on overtime payments, pay-in-lieu of overtime for exempt personnel, special lump-sum recognition awards and lump-sum merit awards included in compensation for determining the amount of participant contributions. Once made, OGE Energy's contribution may be directed to any available investment option in the 401(k) Plan. OGE Energy match contributions vest over a three-year period. After two years of service, participants become 20 percent vested in their OGE Energy contribution account and become fully vested on completing three years of service. In addition, participants fully vest when they are eligible for normal or early retirement under the Pension Plan requirements, in the event of their termination due to death or permanent disability or upon attainment of age 65 while employed by OGE Energy or its affiliates. OGE Energy contributed $15.4 million, $18.2 million and $14.4 million in 2021, 2020 and 2019, respectively, to the 401(k) Plan, of which $12.0 million, $14.3 million and $11.0 million, respectively, related to OG&E. Deferred Compensation Plan OGE Energy provides a nonqualified deferred compensation plan which is intended to be an unfunded plan. The plan's primary purpose is to provide a tax-deferred capital accumulation vehicle for a select group of management, highly compensated employees and non-employee members of OGE Energy's Board of Directors and to supplement such employees' 401(k) Plan contributions as well as offering this plan to be competitive in the marketplace. Eligible employees who enroll in the plan have the following deferral options: (i) eligible employees may elect to defer up to a maximum of 70 percent of base salary and 100 percent of annual bonus awards or (ii) eligible employees may elect a deferral percentage of base salary and bonus awards based on the deferral percentage elected for a year under the 401(k) Plan with such deferrals to start when maximum deferrals to the qualified 401(k) Plan have been made because of limitations in that plan. Eligible directors who enroll in the plan may elect to defer up to a maximum of 100 percent of directors' meeting fees and annual retainers. OGE Energy matches employee (but not non-employee director) deferrals to make up for any match lost in the 401(k) Plan because of deferrals to the deferred compensation plan and to allow for a match that would have been made under the 401(k) Plan on that portion of either the first six percent of total compensation or the first five percent of total compensation, depending on prior participant elections, deferred that exceeds the limits allowed in the 401(k) Plan. Matching credits vest based on years of service, with full vesting after three years or, if earlier, on retirement, disability, death, a change in control of OGE Energy or termination of the plan. Deferrals, plus any OGE Energy match, are credited to a recordkeeping account in the participant's name. Earnings on the deferrals are indexed to the assumed investment funds selected by the participant. In 2021, those investment options included an OGE Energy Common Stock fund, whose value was determined based on the stock price of OGE Energy's Common Stock. OGE Energy accounts for the contributions related to its executive officers in this plan as Accrued Benefit Obligations and accounts for the contributions related to OGE Energy's directors in this plan as Other Deferred Credits and Other Liabilities in the balance sheets. The investment associated with these contributions is accounted for as Other Property and Investments in the balance sheets. The appreciation of these investments is accounted for as Other Income, and the increase in the liability under the plan is accounted for as Other Expense in the statements of income.

Fair Value Measures and Disclos

Fair Value Measures and Disclosures (Policies)	12 Months Ended
	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Fair Value Measurement, Policy	Nonrecurring Fair Value Measurements As further discussed in Note 5, OGE Energy recorded an impairment on its investment in Enable in March 2020. The nonrecurring fair value measurement consisted of calculating a 20-trading day volume weighted average price for Enable's common units through March 31, 2020. This method of valuation was determined to be representative of the fair value of Enable's common units as it incorporated market prices during the period and reduced the impact of volatility that a single day could represent. OGE Energy concluded that this valuation method resulted in a Level 3 nonrecurring fair value measurement.

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Regulatory Assets and Liabilities [Table Text Block]	The following table presents a summary of OG&E's regulatory assets and liabilities. December 31 (In millions) 2021 2020 REGULATORY ASSETS Current: Fuel clause under recoveries $ 151.9 $ — Oklahoma Energy Efficiency Rider under recoveries (A) 11.7 — SPP cost tracker under recovery (A) 9.3 7.0 Generation Capacity Replacement Rider under recovery (A) 1.0 4.4 Other (A) 8.7 8.4 Total current regulatory assets $ 182.6 $ 19.8 Non-current: Oklahoma Winter Storm Uri costs $ 747.9 $ — Oklahoma deferred storm expenses 172.8 158.8 Benefit obligations regulatory asset 109.2 164.9 Arkansas Winter Storm Uri costs 88.9 — Pension tracker 42.9 18.1 Sooner Dry Scrubbers 18.9 19.7 Arkansas deferred pension expenses 12.1 9.3 Unamortized loss on reacquired debt 8.9 9.7 COVID-19 impacts 8.2 6.4 Frontier Plant deferred expenses 6.7 6.4 Smart Grid 3.9 11.2 Other 10.4 11.1 Total non-current regulatory assets $ 1,230.8 $ 415.6 REGULATORY LIABILITIES Current: Fuel clause over recoveries $ — $ 28.6 Other (B) 2.5 6.5 Total current regulatory liabilities $ 2.5 $ 35.1 Non-current: Income taxes refundable to customers, net $ 930.7 $ 867.4 Accrued removal obligations, net 296.8 316.8 Other 3.6 4.7 Total non-current regulatory liabilities $ 1,231.1 $ 1,188.9 (A) Included in Other Current Assets in the balance sheets.
Components of Benefit Obligation Regulatory Asset [Table Text Block]	The following table presents a summary of the components of the benefit obligations regulatory asset. December 31 (In millions) 2021 2020 Pension Plan and Restoration of Retirement Income Plan: Net loss $ 89.6 $ 147.3 Postretirement Benefit Plans: Net loss 23.2 26.2 Prior service cost (3.6) (8.6) Total $ 109.2 $ 164.9
Schedule of Jointly Owned Utility Plants [Table Text Block]	The following tables present OG&E's ownership interest in the jointly-owned McClain Plant and the jointly-owned Redbud Plant, and, as disclosed below, only OG&E's ownership interest is reflected in the property, plant and equipment and accumulated depreciation balances in these tables. The owners of the remaining interests in the McClain Plant and the Redbud Plant are responsible for providing their own financing of capital expenditures. Also, only OG&E's proportionate interests of any direct expenses of the McClain Plant and the Redbud Plant, such as fuel, maintenance expense and other operating expenses, are included in the applicable financial statement captions in the statements of income. December 31, 2021 (In millions) Percentage Ownership Total Property, Plant and Equipment Accumulated Depreciation Net Property, Plant and Equipment McClain Plant (A) 77 % $ 258.5 $ 109.0 $ 149.5 Redbud Plant (A)(B) 51 % $ 538.2 $ 203.4 $ 334.8 (A) Construction work in progress was $0.2 million and $0.2 million for the McClain and Redbud Plants, respectively. (B) This amount includes a plant acquisition adjustment of $148.3 million and accumulated amortization of $72.8 million. December 31, 2020 (In millions) Percentage Ownership Total Property, Plant and Equipment Accumulated Depreciation Net Property, Plant and Equipment McClain Plant (A) 77 % $ 257.1 $ 96.0 $ 161.1 Redbud Plant (A)(B) 51 % $ 531.8 $ 181.9 $ 349.9 (A) Construction work in progress was $0.1 million and $1.8 million for the McClain and Redbud Plants, respectively. (B) This amount includes a plant acquisition adjustment of $148.3 million and accumulated amortization of $67.3 million.
Property, Plant and Equipment [Table Text Block]	The following tables present the Registrants' major classes of property, plant and equipment and related accumulated depreciation. December 31, 2021 (In millions) Total Property, Plant and Equipment Accumulated Depreciation Net Property, Plant and Equipment OG&E: Distribution assets $ 5,225.8 $ 1,477.5 $ 3,748.3 Electric generation assets (A) 5,037.9 1,839.0 3,198.9 Transmission assets (B) 3,038.2 627.0 2,411.2 Intangible plant 301.1 171.7 129.4 Other property and equipment 542.7 203.7 339.0 OG&E property, plant and equipment 14,145.7 4,318.9 9,826.8 Non-OG&E property, plant and equipment 6.1 — 6.1 Total OGE Energy property, plant and equipment $ 14,151.8 $ 4,318.9 $ 9,832.9 (A) This amount includes a plant acquisition adjustment of $148.3 million and accumulated amortization of $72.8 million. (B) This amount includes a plant acquisition adjustment of $3.3 million and accumulated amortization of $0.9 million. December 31, 2020 (In millions) Total Property, Plant and Equipment Accumulated Depreciation Net Property, Plant and Equipment OG&E: Distribution assets $ 4,809.9 $ 1,422.1 $ 3,387.8 Electric generation assets (A) 4,932.2 1,713.6 3,218.6 Transmission assets (B) 2,944.6 591.7 2,352.9 Intangible plant 254.1 153.9 100.2 Other property and equipment 495.3 186.3 309.0 OG&E property, plant and equipment 13,436.1 4,067.6 9,368.5 Non-OG&E property, plant and equipment 6.1 — 6.1 Total OGE Energy property, plant and equipment $ 13,442.2 $ 4,067.6 $ 9,374.6 (A) This amount includes a plant acquisition adjustment of $148.3 million and accumulated amortization of $67.3 million. (B) This amount includes a plant acquisition adjustment of $3.3 million and accumulated amortization of $0.9 million.
Schedule of Change in Asset Retirement Obligation [Table Text Block]	The following table presents changes to OG&E's asset retirement obligations during the years ended December 31, 2021 and 2020. (In millions) 2021 2020 Balance at January 1 $ 79.6 $ 73.5 Accretion expense 0.6 0.5 Revisions in estimated cash flows (A) — 5.8 Liabilities settled (B) — (0.2) Balance at December 31 $ 80.2 $ 79.6 (A) Assumptions changed related to the estimated timing and estimated cost of the removal of asbestos at OG&E's generating facilities.
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]	The following table presents changes in the components of accumulated other comprehensive income (loss) attributable to OGE Energy during 2020 and 2021. All amounts below are presented net of tax. Pension Plan and Restoration of Retirement Income Plan Postretirement Benefit Plans (In millions) Net Gain Prior Service Cost (Credit) Net Gain (Loss) Prior Service Cost (Credit) Other Comprehensive Gain (Loss) from Unconsolidated Affiliates Total Balance at December 31, 2019 $ (34.9) $ (0.2) $ 4.2 $ 3.6 $ (0.6) $ (27.9) Other comprehensive income (loss) before reclassifications (5.1) — (2.4) — (0.7) (8.2) Amounts reclassified from accumulated other comprehensive income (loss) 3.9 — (0.1) (1.7) — 2.1 Curtailment — — (0.3) — — (0.3) Settlement cost 2.2 — — — — 2.2 Net current period other comprehensive income (loss) 1.0 — (2.8) (1.7) (0.7) (4.2) Balance at December 31, 2020 (33.9) (0.2) 1.4 1.9 (1.3) (32.1) Other comprehensive income (loss) before reclassifications 1.4 (1.1) (0.7) — 1.3 0.9 Amounts reclassified from accumulated other comprehensive income (loss) 1.6 0.1 0.1 (1.4) — 0.4 Settlement cost 6.0 — — — — 6.0 Net current period other comprehensive income (loss) 9.0 (1.0) (0.6) (1.4) 1.3 7.3 Balance at December 31, 2021 $ (24.9) $ (1.2) $ 0.8 $ 0.5 $ — $ (24.8)
Reclassification out of Accumulated Other Comprehensive Income [Table Text Block]	The following table presents significant amounts reclassified out of accumulated other comprehensive income (loss) by the respective line items in net income (loss) during the years ended December 31, 2021 and 2020. Details about Accumulated Other Comprehensive Income (Loss) Components Amount Reclassified from Accumulated Other Comprehensive Income (Loss) Affected Line Item in Year Ended December 31, (In millions) 2021 2020 Amortization of Pension Plan and Restoration of Retirement Income Plan items: Actuarial losses $ (2.5) $ (5.1) (A) Prior service cost (0.1) — (A) Settlement cost (8.7) (2.9) (A) (11.3) (8.0) Income (Loss) Before Taxes (3.6) (1.9) Income Tax Expense (Benefit) $ (7.7) $ (6.1) Net Income (Loss) Amortization of postretirement benefit plans items: Prior service credit $ 1.8 $ 2.3 (A) Curtailment cost — 0.4 (A) Actuarial gains (losses) (0.1) 0.1 (A) 1.7 2.8 Income (Loss) Before Taxes 0.4 0.7 Income Tax Expense (Benefit) $ 1.3 $ 2.1 Net Income (Loss) Total reclassifications for the period, net of tax $ (6.4) $ (4.0) Net Income (Loss) (A) These accumulated other comprehensive income (loss) components are included in the computation of net periodic benefit cost (see Note 13 for additional information).

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	12 Months Ended
	Dec. 31, 2021
Revenue from Contract with Customer [Abstract]
Disaggregation of Revenue [Table Text Block]	The following table presents OG&E's revenues from contracts with customers disaggregated by customer classification. OG&E's operating revenues disaggregated by customer classification can be found in "OG&E (Electric Utility) Results of Operations" within "Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations." Year Ended December 31, (In millions) 2021 2020 2019 Residential $ 1,309.1 $ 842.7 $ 865.8 Commercial 749.2 465.6 486.6 Industrial 323.0 192.6 217.8 Oilfield 312.8 169.2 200.4 Public authorities and street light 284.4 172.3 190.3 System sales revenues 2,978.5 1,842.4 1,960.9 Provision for rate refund — 3.8 (0.9) Integrated market 468.9 49.6 38.4 Transmission 140.2 143.3 148.0 Other 1.1 30.7 29.1 Revenues from contracts with customers (A) $ 3,588.7 $ 2,069.8 $ 2,175.5 (A) In February 2021, Winter Storm Uri resulted in record winter peak demand for electricity and extremely high natural gas and purchased power prices in OG&E's service territory. Operating revenues significantly increased due to increased fuel, purchased power and direct transmission expenses, which are generally recoverable from customers, as a result of Winter Storm Uri. For further discussion, see Note 16 and "Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations."

Leases, Codification Topic 842

Leases, Codification Topic 842 (Tables)	12 Months Ended
	Dec. 31, 2021
Leases [Abstract]
Lease, Cost	The following tables present amounts recognized for operating leases in the Registrants' income statements, cash flow statements and balance sheets and supplemental information related to those amounts recognized. OGE Energy OG&E Year Ended December 31, Year Ended December 31, (In millions) 2021 2020 2019 2021 2020 2019 Operating lease cost $ 6.3 $ 6.4 $ 6.0 $ 5.7 $ 5.5 $ 5.1 Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows for operating leases $ 6.3 $ 6.4 $ 5.6 $ 5.7 $ 5.5 $ 4.8 Right-of-use assets obtained in exchange for new operating lease liabilities $ — $ 1.4 $ 10.7 $ — $ 1.4 $ 10.7 OGE Energy OG&E (Dollars in millions) December 31, 2021 December 31, 2020 December 31, 2021 December 31, 2020 Right-of-use assets at period end (A) $ 33.0 $ 37.6 $ 33.0 $ 37.0 Operating lease liabilities at period end (B) $ 37.6 $ 42.3 $ 37.6 $ 41.7 Operating lease weighted-average remaining lease term (in years) 12.2 12.5 12.2 12.7 Operating lease weighted-average discount rate 3.9 % 3.9 % 3.9 % 3.9 % (A) Included in Property, Plant and Equipment in the Registrants' balance sheets. (B) Included in Other Deferred Credits and Other Liabilities in the Registrants' balance sheets. The following table presents a maturity analysis of the Registrants' operating lease liabilities. Future minimum operating lease payments as of December 31: OGE Energy OG&E (In millions) 2022 $ 5.7 $ 5.7 2023 5.1 5.1 2024 3.1 3.1 2025 3.0 3.0 2026 3.0 3.0 Thereafter 28.7 28.7 Total future minimum lease payments 48.6 48.6 Less: Imputed interest 11.0 11.0 Present value of net minimum lease payments $ 37.6 $ 37.6

Investment in Unconsolidated _2

Investment in Unconsolidated Affiliate (Tables)	12 Months Ended
	Dec. 31, 2021
Equity Method Investments and Joint Ventures [Abstract]
Summarized Balance Sheet Financial Information, Equity Method Investment [Table Text Block]	The following tables present summarized unaudited financial information for 100 percent of Enable as of December 2, 2021 and December 31, 2020 and for the period of January 1, 2021 through December 2, 2021 and the years ended December 31, 2020 and 2019. Balance Sheet December 2, 2021 December 31, 2020 (In millions) Current assets $ 594 $ 381 Non-current assets $ 11,227 $ 11,348 Current liabilities $ 1,254 $ 582 Non-current liabilities $ 3,281 $ 4,052
Summarized Income Statement Financial Information, Equity Method Investment [Table Text Block]	Period of January 1, 2021 through December 2, 2021 Year Ended Income Statement December 31, 2020 December 31, 2019 (In millions) Total revenues $ 3,466 $ 2,463 $ 2,960 Cost of natural gas and NGLs (excluding depreciation and amortization) $ 1,959 $ 965 $ 1,279 Operating income $ 634 $ 465 $ 569 Net income $ 461 $ 52 $ 360
Reconciliation of Equity in Earnings of Unconsolidated Affiliates [Table Text Block]	The following table presents a reconciliation of OGE Energy's equity in earnings (losses) of unconsolidated affiliates for the period of January 1, 2021 through December 2, 2021 and the years ended December 31, 2020 and 2019. For further discussion of Enable's net income, see "Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations - Results of Operations - OGE Holdings (Natural Gas Midstream Operations)." Period of January 1, 2021 through December 2, 2021 Year Ended (In millions) December 31, 2020 December 31, 2019 Enable net income $ 461.0 $ 52.0 $ 360.0 Differences due to timing of OGE Energy and Enable accounting close 9.0 — — Enable net income used to calculate OGE Energy's equity in earnings $ 470.0 $ 52.0 $ 360.0 OGE Energy's percent ownership at period end 25.5 % 25.5 % 25.5 % OGE Energy's portion of Enable net income $ 119.8 $ 13.2 $ 91.8 Amortization of basis difference and dilution recognition (A) 50.0 98.8 22.1 Impairment of OGE Energy's equity method investment in Enable (B) — (780.0) — Equity in earnings (losses) of unconsolidated affiliates (C) $ 169.8 $ (668.0) $ 113.9 (A) Includes loss on dilution, net of proportional basis difference recognition. (B) Effective March 31, 2020, OGE Energy estimated the fair value of its investment in Enable was below the book value and concluded the decline in value was not temporary due to the severity of the decline and recent rapid deterioration, as well as the near term future outlook, of the midstream oil and gas industry. Accordingly, OGE Energy recorded a $780.0 million impairment on its investment in Enable in 2020. Further information concerning the fair value method used to measure the impairment on OGE Energy's investment in Enable can be found in Note 7. (C) For the year ended December 31, 2020, Enable recorded a $225.0 million impairment on its SESH equity method investment. Enable estimated the fair value of this equity method investment was below the carrying value at September 30, 2020 and concluded the decline in value was other than temporary due to the expiration of a transportation contract and the current status of renewal negotiations. The impairment ran through OGE Energy's portion of Enable net income and was offset by basis differences that flow through the amortization of basis difference and dilution recognition line item above.
Schedule of Related Party Transactions [Table Text Block]	The following table presents summarized related party transactions between OG&E and Enable during the period of January 1, 2021 through December 2, 2021 and the years ended December 31, 2020 and 2019. Period of January 1, 2021 through December 2, 2021 Year Ended (In millions) December 31, 2020 December 31, 2019 Operating revenues: Electricity to power electric compression assets $ 13.3 $ 15.1 $ 15.9 Fuel, purchased power and direct transmission expense: Natural gas transportation services $ 32.7 $ 32.8 $ 41.2 Natural gas purchases (sales) $ (33.5) $ 2.7 $ (6.0)

Related Party Disclosures (Tabl

Related Party Disclosures (Tables)	12 Months Ended
	Dec. 31, 2021
Related Party Transactions [Abstract]
Schedule of Related Party Transactions [Table Text Block]	The following table presents summarized related party transactions between OG&E and Enable during the period of January 1, 2021 through December 2, 2021 and the years ended December 31, 2020 and 2019. Period of January 1, 2021 through December 2, 2021 Year Ended (In millions) December 31, 2020 December 31, 2019 Operating revenues: Electricity to power electric compression assets $ 13.3 $ 15.1 $ 15.9 Fuel, purchased power and direct transmission expense: Natural gas transportation services $ 32.7 $ 32.8 $ 41.2 Natural gas purchases (sales) $ (33.5) $ 2.7 $ (6.0)

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2021
Fair Value Disclosures [Abstract]
Fair Value, by Balance Sheet Grouping [Table Text Block]	The following table presents OGE Energy's financial instrument measured at fair value on a recurring basis and the carrying amount and fair value of the Registrants' financial instruments at December 31, 2021 and 2020, as well as the classification level within the fair value hierarchy. 2021 2020 December 31 (In millions) Carrying Amount Fair Carrying Amount Fair Classification Financial instrument measured at fair value on a recurring basis: OGE Energy investment in Energy Transfer's equity securities $ 785.1 $ 785.1 (A) (A) Level 1 Financial instruments for which fair value is only disclosed: Long-term Debt (including Long-term Debt due within one year): OGE Energy Senior Notes $ 499.9 $ 497.8 $ — $ — Level 2 OG&E Senior Notes $ 3,851.8 $ 4,460.2 $ 3,349.6 $ 4,182.1 Level 2 OG&E Industrial Authority Bonds $ 135.4 $ 135.4 $ 135.4 $ 135.4 Level 2 Tinker Debt $ 9.3 $ 10.0 $ 9.4 $ 10.7 Level 3 (A) OGE Energy's ownership of Energy Transfer securities was effective as of December 2, 2021; therefore, the investment in Energy Transfer's equity securities was not held at December 31, 2020.

Stock Based Compensation (Table

Stock Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2021
Stock-Based Compensation [Abstract]
Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block]	The following table presents the Registrants' pre-tax compensation expense and related income tax benefit for the years ended December 31, 2021, 2020 and 2019 related to performance units and restricted stock units for the Registrants' employees. OGE Energy OG&E Year Ended December 31 (In millions) 2021 2020 2019 2021 2020 2019 Performance units: Total shareholder return $ 7.5 $ 7.9 $ 8.7 $ 1.8 $ 2.3 $ 3.0 Earnings per share — 1.0 4.3 — 0.3 1.5 Total performance units 7.5 8.9 13.0 1.8 2.6 4.5 Restricted stock units 2.3 0.9 0.9 0.4 0.4 0.4 Total compensation expense $ 9.8 $ 9.8 $ 13.9 $ 2.2 $ 3.0 $ 4.9 Income tax benefit $ 2.5 $ 2.5 $ 3.6 $ 0.6 $ 0.8 $ 1.3
Performance Units Total Shareholder Return Valuation Assumptions [Table Text Block]	The following table presents the number of performance units granted based on total shareholder return and the assumptions used to calculate the grant date fair value of the performance units based on total shareholder return. OGE Energy OG&E 2021 2020 2019 2021 2020 2019 Number of units granted 249,909 201,552 208,647 68,720 67,975 68,396 Fair value of units granted $ 38.14 $ 38.03 $ 47.00 $ 38.14 $ 38.03 $ 47.00 Expected dividend yield 4.7 % 3.5 % 4.0 % 4.7 % 3.5 % 4.0 % Expected price volatility 29.0 % 15.0 % 17.0 % 29.0 % 15.0 % 17.0 % Risk-free interest rate 0.22 % 1.17 % 2.47 % 0.22 % 1.17 % 2.47 % Expected life of units (in years) 2.84 2.85 2.86 2.85 2.85 2.86
Restricted Stock Valuation Assumptions [Table Text Block]	The following table presents the number of restricted stock units granted and the grant date fair value. OGE Energy OG&E 2021 2020 2019 2021 2020 2019 Restricted stock units granted 89,197 67,193 75,929 22,911 22,665 26,141 Fair value of restricted stock units granted $ 31.11 $ 43.69 $ 41.71 $ 30.91 $ 43.69 $ 41.63
Share-based Compensation, Activity [Table Text Block]	The following tables present a summary of the activity for the Registrants' performance units and restricted stock units for the year ended December 31, 2021. The table designated as "OGE Energy" below includes the OG&E standalone activity, as OGE Energy represents consolidated results. OGE Energy Performance Units Restricted Total Shareholder Return Earnings Per Share (Dollars in millions) Number Aggregate Intrinsic Value Number Aggregate Intrinsic Value Number Aggregate Intrinsic Value Units/shares outstanding at 12/31/20 612,262 79,002 124,919 Granted 249,909 (A) — 89,197 Converted (236,990) (B) $ 5.4 (79,002) (B) $ 2.7 — Vested N/A N/A (53,274) $ 2.2 Forfeited (43,929) — (27,171) Units/shares outstanding at 12/31/21 581,252 $ 17.5 — $ — 133,671 $ 5.1 Units/shares fully vested at 12/31/21 172,748 $ — — $ — 47,907 $ 2.0 OG&E Performance Units Restricted Total Shareholder Return Earnings Per Share (Dollars in millions) Number Aggregate Intrinsic Value Number Aggregate Intrinsic Value Number Aggregate Intrinsic Value Units/shares outstanding at 12/31/20 182,363 25,235 34,130 Granted 68,720 (A) — 22,911 Converted (75,693) (B) $ 1.7 (25,235) (B) $ 0.8 — Vested N/A N/A (12,461) $ 0.6 Forfeited (14,132) — (8,986) Employee migration 52 (C) — (C) 19 (C) Units/shares outstanding at 12/31/21 161,310 $ 4.8 — $ — 35,613 $ 1.4 Units/shares fully vested at 12/31/21 48,195 $ — — $ — 11,241 $ 0.5 (A) For performance units, this represents the target number of performance units granted. Actual number of performance units earned, if any, is dependent upon performance and may range from zero percent to 200 percent of the target. (B) These amounts represent performance units that vested at December 31, 2020 which were settled in February 2021.
Schedule of Nonvested Share Activity [Table Text Block]	The following tables present a summary of the activity for the Registrants' non-vested performance units and restricted stock units for the year ended December 31, 2021. The table designated as "OGE Energy" below includes the OG&E standalone activity, as OGE Energy represents consolidated results. OGE Energy Performance Units - Restricted Total Shareholder Return Number Weighted-Average Number Weighted-Average Units/shares non-vested at 12/31/20 375,272 $ 42.51 124,919 $ 42.69 Granted 249,909 (A) $ 38.14 89,197 $ 31.11 Vested (172,748) $ 47.00 (53,274) $ 41.59 Forfeited (43,929) $ 41.02 (27,171) $ 42.37 Units/shares non-vested at 12/31/21 408,504 $ 38.05 133,671 $ 35.64 OG&E Performance Units - Restricted Total Shareholder Return Number Weighted-Average Number Weighted-Average Units/shares non-vested at 12/31/20 106,670 $ 42.49 34,130 $ 42.67 Granted 68,720 (A) $ 38.14 22,911 $ 30.91 Vested (48,195) $ 47.00 (12,461) $ 45.67 Forfeited (14,132) $ 41.12 (8,986) $ 42.51 Employee migration 52 (B) $ 41.01 19 (B) $ 37.71 Units/shares non-vested at 12/31/21 113,115 $ 38.10 35,613 $ 35.52 (A) For performance units, this represents the target number of performance units granted. Actual number of performance units earned, if any, is dependent upon performance and may range from zero percent to 200 percent of the target.
Fair Value of Vested Performance Units and Restricted Stock [Table Text Block]	The following table presents a summary of the Registrants' fair value for vested performance units and restricted stock units. OGE Energy OG&E Year Ended December 31 (In millions) 2021 2020 2019 2021 2020 2019 Performance units: Total shareholder return $ 8.1 $ 8.7 $ 9.3 $ 2.3 $ 2.8 $ 3.2 Earnings per share $ — $ 2.5 $ 5.2 $ — $ 0.8 $ 0.9 Restricted stock units $ 2.2 $ 0.1 $ 0.1 $ 0.5 $ 0.1 $ —
Schedule of Unrecognized Compensation Cost, Nonvested Awards [Table Text Block]	The following table presents a summary of the Registrants' unrecognized compensation cost for non-vested performance units and restricted stock units and the weighted-average periods over which the compensation cost is expected to be recognized. OGE Energy OG&E December 31, 2021 Unrecognized Compensation Cost (In millions) Weighted Average to be Recognized (In years) Unrecognized Compensation Cost (In millions) Weighted Average to be Recognized (In years) Performance units - total shareholder return $ 7.5 1.71 $ 2.0 1.72 Restricted stock units 3.5 1.48 0.8 1.39 Total unrecognized compensation cost $ 11.0 $ 2.8

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2021
Income Taxes [Abstract]
Schedule of Components of Income Tax Expense (Benefit) [Table Text Block]	The following table presents the components of income tax expense (benefit). OGE Energy OG&E Year Ended December 31 (In millions) 2021 2020 2019 2021 2020 2019 Provision (benefit) for current income taxes: Federal $ 16.4 $ 8.4 $ (6.4) $ (9.0) $ (3.8) $ (7.9) State 1.7 0.5 5.1 9.0 (0.6) 4.1 Total provision (benefit) for current income taxes 18.1 8.9 (1.3) — (4.4) (3.8) Provision (benefit) for deferred income taxes, net: Federal 133.1 (105.2) 48.5 58.3 45.7 37.7 State (10.0) (31.1) (17.4) (16.5) (6.6) (13.8) Total provision (benefit) for deferred income taxes, net 123.1 (136.3) 31.1 41.8 39.1 23.9 Total income tax expense (benefit) $ 141.2 $ (127.4) $ 29.8 $ 41.8 $ 34.7 $ 20.1
Schedule of Effective Income Tax Rate Reconciliation [Table Text Block]	The following table presents a reconciliation of the statutory tax rates to the effective income tax rate. OGE Energy OG&E Year Ended December 31 2021 2020 2019 2021 2020 2019 Statutory federal tax rate 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % 21.0 % State income taxes, net of federal income tax 0.9 (1.4) (1.2) (1.4) (1.6) (1.8) Stock-based compensation 0.1 (0.3) (1.2) — — — Executive compensation limitation 0.1 0.2 0.2 — — — Amortization of net unfunded deferred taxes (2.1) (4.4) (4.5) (4.6) (4.8) (5.6) Federal renewable energy credit (A) (2.0) (5.0) (6.0) (4.4) (5.4) (7.6) Remeasurement of state deferred taxes due to Energy Transfer merger (B) (1.1) — — — — — Remeasurement of state deferred tax liabilities (0.6) 0.9 (0.8) — — — 401(k) dividends (0.2) (0.4) (0.4) — — — Impairment of OGE Energy's investment in Enable (C) — 31.6 — — — — Other — 0.1 (0.7) (0.2) 0.1 (0.6) Effective income tax rate 16.1 % 42.3 % 6.4 % 10.4 % 9.3 % 5.4 % (A) Represents credits primarily associated with the production from OG&E's wind farms. (B) In connection with the Enable and Energy Transfer merger, the state income tax rates are expected to decrease, as Energy Transfer operates in significantly more states with generally lower tax rates than the historic Enable operating area. (C) As further discussed in Note 5, OGE Energy recorded a $780.0 million impairment on its investment in Enable in March 2020, which resulted in a tax benefit being recorded that caused a significant variance to the effective tax rate. This variance has been presented in the table as a single line item in order to facilitate comparability of other components of the effective tax rate.
Schedule of Deferred Tax Assets and Liabilities [Table Text Block]	The following table presents the components of Deferred Income Taxes at December 31, 2021 and 2020. OGE Energy OG&E December 31 (In millions) 2021 2020 2021 2020 Deferred income tax liabilities, net: Accelerated depreciation and other property related differences $ 1,677.3 $ 1,721.2 $ 1,677.3 $ 1,721.2 Investment in Enable — 302.6 — — Investment in Energy Transfer's equity securities 363.5 — — — Regulatory assets 52.1 52.3 52.1 52.3 Pension Plan 10.7 3.9 32.0 27.4 Other 7.4 (1.4) (4.7) (6.5) Derivative instruments 2.2 1.7 — — Bond redemption-unamortized costs 1.8 2.0 1.8 2.0 Income taxes recoverable from customers, net (225.8) (221.8) (225.8) (221.8) State tax credits (221.2) (204.4) (205.9) (189.0) Federal tax credits (208.4) (236.6) (209.8) (236.6) Regulatory liabilities (72.0) (81.0) (72.0) (81.0) Asset retirement obligations (19.4) (20.3) (19.4) (20.3) Postretirement medical and life insurance benefits (19.2) (22.4) (13.0) (15.3) Accrued liabilities (9.5) (9.6) (7.3) (5.2) Deferred federal investment tax credits (3.1) (2.7) (3.1) (2.7) Net operating losses (1.0) (12.0) — (1.4) Accrued vacation (1.5) (2.2) (1.2) (1.6) Uncollectible accounts (0.6) (0.7) (0.6) (0.7) Total deferred income tax liabilities, net $ 1,333.3 $ 1,268.6 $ 1,000.4 $ 1,020.8
Schedule of Unrecognized Tax Benefits Roll Forward [Table Text Block]	The following table presents a reconciliation of the Registrants' total gross unrecognized tax benefits as of the years ended December 31, 2021, 2020 and 2019. (In millions) 2021 2020 2019 Balance at January 1 $ 21.9 $ 20.7 $ 20.7 Tax positions related to current year: Additions 1.7 1.2 — Reductions (1.2) — — Balance at December 31 $ 22.4 $ 21.9 $ 20.7
Summary of Tax Credit Carryforwards [Table Text Block]	The following table presents a summary of these carry forwards. OGE Energy OG&E (In millions) Carry Forward Amount Deferred Tax Asset Carry Forward Amount Deferred Tax Asset Earliest Expiration Date State operating loss $ 33.4 $ 1.0 $ — $ — 2032 Federal tax credits $ 208.4 $ 208.4 $ 209.8 $ 209.8 2032 State tax credits: Oklahoma investment tax credits $ 227.1 $ 179.4 $ 207.8 $ 164.2 N/A Oklahoma capital investment board credits $ 12.8 $ 12.8 $ 12.8 $ 12.8 N/A Oklahoma zero emission tax credits $ 37.5 $ 28.9 $ 37.5 $ 28.9 2021 Louisiana inventory credits $ 0.1 $ 0.1 $ — $ — 2032 N/A - not applicable Oklahoma Corporate Tax Rate Change In May 2021, Oklahoma enacted a reduction of the corporate income tax rate to four percent from the previous six percent. This rate reduction took effect on January 1, 2022. ASC 740, "Income Taxes," requires deferred tax assets and liabilities to be measured at the enacted tax rate expected to apply when temporary differences are to be realized or settled. Therefore, during the second quarter of 2021, the Registrants revalued state deferred tax liabilities to reflect this change in tax rate. For entities subject to ASC 980, "Accounting for Regulated Entities," such as OG&E, those entities are required to recognize a regulatory liability for the decrease in taxes payable for the change in tax rates that are expected to be returned to customers through future rates and to recognize a regulatory asset for the increase in taxes receivable for the change in tax rates that are expected to be recovered from customers through future rates. The revaluation resulted in a regulatory liability of $97.7 million recorded for OG&E and an income tax benefit of $6.6 million for OGE Energy related to Enable and other operations (holding company) for the year ended December 31, 2021.

Common Equity (Tables)

Common Equity (Tables)	12 Months Ended
	Dec. 31, 2021
Equity [Abstract]
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	The following table presents the calculation of basic and diluted earnings (loss) per share for OGE Energy. (In millions except per share data) 2021 2020 2019 Net income (loss) $ 737.3 $ (173.7) $ 433.6 Average common shares outstanding: Basic average common shares outstanding 200.1 200.1 200.1 Effect of dilutive securities: Contingently issuable shares (performance and restricted stock units) 0.2 — 0.6 Diluted average common shares outstanding 200.3 200.1 200.7 Basic earnings (loss) per average common share $ 3.68 $ (0.87) $ 2.17 Diluted earnings (loss) per average common share $ 3.68 $ (0.87) $ 2.16 Anti-dilutive shares excluded from earnings per share calculation — 0.3 —

Long-Term Debt (Tables)

Long-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2021
Long-term Debt, Unclassified [Abstract]
Schedule of Long-term Debt Instruments [Table Text Block]	OG&E has tax-exempt pollution control bonds with optional redemption provisions that allow the holders to request repayment of the bonds on any business day. The following table presents information about these bonds, which can be tendered at the option of the holder during the next 12 months. Series Date Due Amount (In millions) 0.11% - 0.27% Garfield Industrial Authority, January 1, 2025 $ 47.0 0.11% - 0.33% Muskogee Industrial Authority, January 1, 2025 32.4 0.11% - 0.27% Muskogee Industrial Authority, June 1, 2027 56.0 Total (redeemable during next 12 months) $ 135.4

Short-Term Debt and Credit Fa_2

Short-Term Debt and Credit Facilities (Tables)	12 Months Ended
	Dec. 31, 2021
Short-term Debt [Abstract]
Schedule of Line of Credit Facilities [Table Text Block]	The following table presents information regarding the Registrants' revolving credit agreements at December 31, 2021. Aggregate Amount Weighted-Average Entity Commitment Outstanding (A) Interest Rate Expiration (In millions) OGE Energy (B) $ 550.0 $ 486.9 0.36 % (E) December 17, 2026 OG&E (C)(D) 550.0 0.4 1.15 % (E) December 17, 2026 Total $ 1,100.0 $ 487.3 0.36 % (A) Includes direct borrowings under the revolving credit agreements, commercial paper borrowings and letters of credit at December 31, 2021. (B) This bank facility is available to back up OGE Energy's commercial paper borrowings and to provide revolving credit borrowings. This bank facility can also be used as a letter of credit facility. (C) This bank facility is available to back up OG&E's commercial paper borrowings and to provide revolving credit borrowings. This bank facility can also be used as a letter of credit facility. (D) OG&E has an intercompany borrowing agreement with OGE Energy whereby OG&E has access to up to $350.0 million of OGE Energy's revolving credit amount. This agreement has a termination date of December 17, 2026. At December 31, 2021, there were $60.0 million in intercompany borrowings under this agreement. (E) Represents the weighted-average interest rate for the outstanding borrowings under the revolving credit agreements, commercial paper borrowings and letters of credit.

Retirement Plans and Postreti_2

Retirement Plans and Postretirement Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2021
Retirement Plans and Postretirement Benefit Plans [Abstract]
Schedule of Accumulated Benefit Obligations in Excess of Fair Value of Plan Assets [Table Text Block]	The details of the funded status of OGE Energy's Pension Plan, the Restoration of Retirement Income Plan and the postretirement benefit plans and the amounts included in the balance sheets for 2021 and 2020 are included in the following tables. These amounts have been recorded in Accrued Benefit Obligations with the offset in Accumulated Other Comprehensive Loss (except OG&E's portion, which is recorded as a regulatory asset as discussed in Note 1) in the balance sheets. The amounts in Accumulated Other Comprehensive Loss and those recorded as a regulatory asset represent a net periodic benefit cost to be recognized in the statements of income in future periods. The benefit obligation for OGE Energy's Pension Plan and the Restoration of Retirement Income Plan represents the projected benefit obligation, while the benefit obligation for the postretirement benefit plans represents the accumulated postretirement benefit obligation. The accumulated postretirement benefit obligation for OGE Energy's Pension Plan and Restoration of Retirement Income Plan differs from the projected benefit obligation in that the former includes no assumption about future compensation levels. OGE Energy's seconded employee contract with Enable was terminated on December 2, 2021. OGE Energy retains the obligations to the balances and accrued benefits of these former employees as of the termination of the contract. OGE Energy OG&E Pension Plan Restoration of Retirement Pension Plan Restoration of Retirement December 31 (In millions) 2021 2020 2021 2020 2021 2020 2021 2020 Change in benefit obligation Beginning obligations $ 654.6 $ 616.1 $ 7.8 $ 10.3 $ 484.1 $ 462.0 $ 3.0 $ 6.1 Service cost 11.2 13.2 0.8 0.8 7.7 9.2 — 0.1 Interest cost 13.3 17.0 0.1 0.2 9.7 12.6 — 0.1 Plan settlements (158.6) (42.8) (4.6) (5.3) (120.4) (33.5) (2.9) (4.5) Plan amendments — — 1.4 — — — — — Plan curtailments — — (0.1) 0.2 — — — — Special termination benefits — 7.6 — — — 5.1 — — Actuarial (gains) losses (3.5) 57.7 0.5 1.6 (6.0) 41.0 0.4 1.2 Benefits paid (14.1) (14.2) — — (11.9) (12.3) — — Ending obligations $ 502.9 $ 654.6 $ 5.9 $ 7.8 $ 363.2 $ 484.1 $ 0.5 $ 3.0 Change in plans' assets Beginning fair value $ 570.3 $ 530.3 $ — $ — $ 420.3 $ 399.1 $ — $ — Actual return on plans' assets 48.4 77.0 — — 35.0 57.0 — — Employer contributions 40.0 20.0 4.6 5.3 30.0 10.0 2.9 4.5 Plan settlements (158.6) (42.8) (4.6) (5.3) (120.4) (33.5) (2.9) (4.5) Benefits paid (14.1) (14.2) — — (11.9) (12.3) — — Ending fair value $ 486.0 $ 570.3 $ — $ — $ 353.0 $ 420.3 $ — $ — Funded status at end of year $ (16.9) $ (84.3) $ (5.9) $ (7.8) $ (10.2) $ (63.8) $ (0.5) $ (3.0) Accumulated postretirement benefit obligation $ 475.2 $ 610.8 $ 5.4 $ 6.9 $ 341.0 $ 454.7 $ 0.4 $ 2.9 For the year ended December 31, 2021, Pension Plan actuarial gains were primarily due to favorable demographic experience and a higher discount rate. These gains were partially offset by a difference in lump sum interest rates and the long-term assumption for Enable seconded employee terminations and more retirements and terminations than expected with lump sum payouts. For the year ended December 31, 2020, Pension Plan actuarial losses were primarily due to movement in the discount rate, special termination benefits due to a voluntary retirement program offered by OGE Energy and more retirements and terminations than expected which were expected to accelerate lump sum payments in 2021. These losses were partially offset by gains from lowering the interest crediting rate and plan mortality assumptions. OGE Energy OG&E Postretirement Benefit Plans Postretirement Benefit Plans December 31 (In millions) 2021 2020 2021 2020 Change in benefit obligation Beginning obligations $ 144.5 $ 136.5 $ 109.5 $ 104.7 Service cost 0.2 0.2 0.1 0.2 Interest cost 3.4 4.2 2.6 3.2 Plan curtailments 1.9 4.0 — 3.1 Participants' contributions 3.5 3.3 2.6 2.4 Actuarial (gains) losses (3.7) 7.3 (2.5) 4.5 Benefits paid (12.5) (11.0) (9.9) (8.6) Ending obligations $ 137.3 $ 144.5 $ 102.4 $ 109.5 Change in plans' assets Beginning fair value $ 47.6 $ 47.0 $ 42.7 $ 41.9 Actual return on plans' assets (0.5) 1.2 (0.5) 1.1 Employer contributions 6.2 7.1 5.0 5.9 Participants' contributions 3.5 3.3 2.6 2.4 Benefits paid (12.5) (11.0) (9.9) (8.6) Ending fair value $ 44.3 $ 47.6 $ 39.9 $ 42.7 Funded status at end of year $ (93.0) $ (96.9) $ (62.5) $ (66.8)
Schedule of Defined Benefit Plans Disclosures [Table Text Block]	The following tables present the net periodic benefit cost components, before consideration of capitalized amounts, of OGE Energy's Pension Plan, Restoration of Retirement Income Plan and postretirement benefit plans that are included in the financial statements. Service cost is presented within Other Operation and Maintenance Expense, and the remaining net period benefit cost components as listed in the following tables are presented within Other Net Periodic Benefit Expense in the statements of income. OG&E recovers specific amounts of pension and postretirement medical costs in rates approved in its Oklahoma rate reviews. In accordance with approved orders, OG&E defers the difference between actual pension and postretirement medical expenses and the amount approved in its last Oklahoma rate review as a regulatory asset or regulatory liability. These amounts have been recorded in the Pension tracker in the regulatory assets and liabilities table in Note 1 and within Other Net Periodic Benefit Expense in the statements of income. OGE Energy OG&E Pension Plan Restoration of Retirement Pension Plan Restoration of Retirement Year Ended December 31 (In millions) 2021 2020 2019 2021 2020 2019 2021 2020 2019 2021 2020 2019 Service cost $ 11.2 $ 13.2 $ 12.9 $ 0.8 $ 0.8 $ 0.5 $ 7.7 $ 9.2 $ 9.0 $ — $ 0.1 $ 0.2 Interest cost 13.3 17.0 20.7 0.1 0.2 0.4 9.7 12.6 15.6 — 0.1 0.2 Expected return on plan assets (34.1) (37.6) (36.1) — — — (24.7) (27.9) (27.6) — — — Amortization of net loss 9.4 17.1 17.3 0.2 0.5 0.5 7.0 12.1 12.9 0.1 0.4 0.3 Plan curtailments — — — — 0.2 — — — — — — — Special termination benefits — 7.6 — — — — — 5.1 — — — — Amortization of unrecognized prior service cost (A) — — — 0.1 — — — — — — — — Settlement cost 41.3 14.1 27.6 2.1 2.7 0.5 33.1 11.4 16.4 1.6 2.4 0.5 Total net periodic benefit cost 41.1 31.4 42.4 3.3 4.4 1.9 32.8 22.5 26.3 1.7 3.0 1.2 Less: Amount paid by unconsolidated affiliates (B) (0.2) 2.0 2.9 0.1 0.1 0.1 Plus: Amount allocated from OGE Energy (B) 6.5 5.9 4.5 1.5 1.3 0.5 Net periodic benefit cost $ 41.3 $ 29.4 $ 39.5 $ 3.2 $ 4.3 $ 1.8 $ 39.3 $ 28.4 $ 30.8 $ 3.2 $ 4.3 $ 1.7 (A) Unamortized prior service cost is amortized on a straight-line basis over the average remaining service period to the first eligibility age of participants who are expected to receive a benefit and are active at the date of the plan amendment. (B) "Amount paid by unconsolidated affiliates" is only applicable to OGE Energy. "Amount allocated from OGE Energy" is only applicable to OG&E. In conjunction with the net periodic benefit cost amounts recognized, as presented in the table above, for the Pension and Restoration of Retirement Income Plans in 2021, 2020 and 2019, the Registrants recognized the following: Year Ended December 31 (In millions) 2021 2020 2019 Increase of regulatory asset related to pension expense to maintain allowed recoverable amount in Oklahoma jurisdiction (A) $ 23.0 $ 13.8 $ 16.1 Deferral of pension expense related to pension settlement, curtailment and special termination benefits charges included in the above line item: Oklahoma jurisdiction (A) $ 37.9 $ 21.6 $ 17.9 Arkansas jurisdiction (A) $ 3.5 $ 2.0 $ 1.7 (A) Included in the pension regulatory asset or liability in each jurisdiction, as indicated in the regulatory assets and liabilities table in Note 1. OGE Energy OG&E Postretirement Benefit Plans Postretirement Benefit Plans Year Ended December 31 (In millions) 2021 2020 2019 2021 2020 2019 Service cost $ 0.2 $ 0.2 $ 0.2 $ 0.1 $ 0.2 $ 0.2 Interest cost 3.4 4.2 5.6 2.6 3.2 4.3 Expected return on plan assets (1.8) (1.8) (1.9) (1.7) (1.7) (1.7) Amortization of net loss 2.8 2.0 2.0 2.7 2.1 2.1 Plan curtailments — 1.5 — — 1.3 — Amortization of unrecognized prior service cost (A) (6.9) (8.4) (8.4) (5.0) (6.1) (6.1) Total net periodic benefit income (2.3) (2.3) (2.5) (1.3) (1.0) (1.2) Less: Amount paid by unconsolidated affiliates (B) (0.5) (0.7) (0.6) Plus: Amount allocated from OGE Energy (B) (0.5) (0.5) (0.6) Net periodic benefit income $ (1.8) $ (1.6) $ (1.9) $ (1.8) $ (1.5) $ (1.8) (A) Unamortized prior service cost is amortized on a straight-line basis over the average remaining service period to the first eligibility age of participants who are expected to receive a benefit and are active at the date of the plan amendment. (B) "Amount paid by unconsolidated affiliates" is only applicable to OGE Energy. "Amount allocated from OGE Energy" is only applicable to OG&E. In conjunction with the net periodic benefit income amounts recognized, as presented in the table above, for the postretirement benefit plans in 2021, 2020 and 2019, the Registrants recognized the following: Year Ended December 31 (In millions) 2021 2020 2019 Increase of regulatory liability related to postretirement expense to maintain allowed recoverable amount in Oklahoma jurisdiction (A) $ 0.4 $ 0.2 $ 1.0 Deferral of postretirement expense related to postretirement plan curtailment charges included in the above line item: Oklahoma jurisdiction (A) $ — $ (1.4) $ — Arkansas jurisdiction (A) $ — $ (0.1) $ —
Schedule of Capitalized Pension and Postretirement Cost [Table Text Block]	The following table presents the amount of net periodic benefit cost capitalized and attributable to each of the Registrants for OGE Energy's Pension Plan and postretirement benefit plans in 2021, 2020 and 2019. OGE Energy OG&E (In millions) 2021 2020 2019 2021 2020 2019 Capitalized portion of net periodic pension benefit cost $ 3.4 $ 3.8 $ 3.6 $ 2.9 $ 3.1 $ 3.0 Capitalized portion of net periodic postretirement benefit cost $ 0.2 $ 0.2 $ 0.2 $ 0.1 $ 0.1 $ 0.1
Schedule of Assumptions Used [Table Text Block]	Rate Assumptions Pension Plan and Postretirement Year Ended December 31 2021 2020 2019 2021 2020 2019 Assumptions to determine benefit obligations: Discount rate 2.75 % 2.30 % 3.15 % 2.80 % 2.45 % 3.25 % Rate of compensation increase 4.20 % 4.20 % 4.20 % N/A N/A N/A Interest crediting rate 3.50 % 3.50 % 4.00 % N/A N/A N/A Assumptions to determine net periodic benefit cost: Discount rate 2.63 % 2.88 % 3.63 % 2.45 % 3.25 % 4.30 % Expected return on plan assets 7.00 % 7.50 % 7.50 % 4.00 % 4.00 % 4.00 % Rate of compensation increase 4.20 % 4.20 % 4.20 % N/A N/A N/A Interest crediting rate 3.50 % 4.00 % 4.00 % N/A N/A N/A
Projected Benefit Obligation Funded Status Thresholds [Table Text Block]	The Pension Plan assets are held in a trust which follows an investment policy and strategy designed to reduce the funded status volatility of the Plan by utilizing liability driven investing. The purpose of liability-driven investing is to structure the asset portfolio to more closely resemble the pension liability and thereby more effectively hedge against changes in the liability. The investment policy follows a glide path approach that shifts a higher portfolio weighting to fixed income as the Plan's funded status increases. The following table presents the targeted fixed income and equity allocations at different funded status levels. Projected Benefit Obligation Funded Status Thresholds <90% 95% 100% 105% 110% 115% 120% Fixed income 50% 58% 65% 73% 80% 85% 90% Equity 50% 42% 35% 27% 20% 15% 10% Total 100% 100% 100% 100% 100% 100% 100%
Pension Plan Equity Asset Allocation Table [Table Text Block]	Within the portfolio's overall allocation to equities, the funds are allocated according to the guidelines in the following table. Asset Class Target Allocation Minimum Maximum Domestic Large Cap Equity 40% 35% 60% Domestic Mid-Cap Equity 15% 5% 25% Domestic Small-Cap Equity 25% 5% 30% International Equity 20% 10% 30%
Schedule of Allocation of Plan Assets [Table Text Block]	The following tables present the postretirement benefit plans' investments that are measured at fair value on a recurring basis at December 31, 2021 and 2020. There were no Level 2 investments held by the postretirement benefit plans at December 31, 2021 and 2020. (In millions) December 31, 2021 Level 1 Level 3 Group retiree medical insurance contract $ 28.1 $ — $ 28.1 Mutual funds 16.2 16.2 — Total OGE Energy plan investments $ 44.3 $ 16.2 $ 28.1 Plan investments attributable to affiliates (4.4) Total OG&E plan investments $ 39.9 (In millions) December 31, 2020 Level 1 Level 3 Group retiree medical insurance contract $ 33.4 $ — $ 33.4 Mutual funds 14.2 14.2 — Total OGE Energy plan investments $ 47.6 $ 14.2 $ 33.4 Plan investments attributable to affiliates (4.9) Total OG&E plan investments $ 42.7
Schedule of Effect of Significant Unobservable Inputs, Changes in Plan Assets [Table Text Block]	The following table presents a reconciliation of the postretirement benefit plans' investments that are measured at fair value on a recurring basis using significant unobservable inputs (Level 3). Year Ended December 31 (In millions) 2021 Group retiree medical insurance contract: Beginning balance $ 33.4 Claims paid (4.9) Net unrealized losses related to instruments held at the reporting date (1.1) Investment fees (0.1) Realized losses (0.1) Interest income 0.7 Dividend income 0.2 Ending balance $ 28.1
Schedule of Expected Benefit Payments [Table Text Block]	The following table presents the benefit payments the Registrants expect to pay related to the Pension Plan and Restoration of Retirement Income Plan. These expected benefits are based on the same assumptions used to measure OGE Energy's benefit obligation at the end of the year and include benefits attributable to estimated future employee service. (In millions) OGE Energy OG&E 2022 $ 95.3 $ 38.8 2023 $ 37.0 $ 30.7 2024 $ 38.4 $ 30.6 2025 $ 36.7 $ 28.7 2026 $ 35.2 $ 28.3 2027-2031 $ 167.4 $ 126.6 The Medicare Prescription Drug, Improvement and Modernization Act of 2003 expanded coverage for prescription drugs. The following table presents the gross benefit payments the Registrants expect to pay related to the postretirement benefit plans, including prescription drug benefits. (In millions) OGE Energy OG&E 2022 $ 12.5 $ 9.6 2023 $ 12.2 $ 9.3 2024 $ 10.6 $ 8.0 2025 $ 10.1 $ 7.6 2026 $ 9.7 $ 7.2 After 2026 $ 40.3 $ 30.2
Defined Benefit Plan, Plan Assets, Category	The following tables present the Pension Plan's investments that are measured at fair value on a recurring basis at December 31, 2021 and 2020. There were no Level 3 investments held by the Pension Plan at December 31, 2021 and 2020. (In millions) December 31, 2021 Level 1 Level 2 Net Asset Value (A) Common stocks $ 86.1 $ 86.1 $ — $ — U.S. Treasury notes and bonds (B) 135.2 135.2 — — Mortgage- and asset-backed securities 24.6 — 24.6 — Corporate fixed income and other securities 107.0 — 107.0 — Commingled fund (C) 23.6 — — 23.6 Foreign government bonds 0.9 — 0.9 — U.S. municipal bonds 1.4 — 1.4 — Money market fund 5.5 — — 5.5 Mutual fund 99.8 99.8 — — Preferred stocks 1.1 1.1 — — U.S. Treasury futures: Cash collateral 0.6 0.6 — — Forward contracts: Receivable (foreign currency) 0.1 — 0.1 — Total Pension Plan investments 485.9 $ 322.8 $ 134.0 $ 29.1 Interest and dividends receivable 2.1 Payable to broker for securities purchased (2.0) Total OGE Energy Pension Plan assets $ 486.0 Pension Plan investments attributable to affiliates (133.0) Total OG&E Pension Plan assets $ 353.0 (A) GAAP allows the measurement of certain investments that do not have a readily determinable fair value at the net asset value. These investments do not consider the observability of inputs; therefore, they are not included within the fair value hierarchy. (B) This category represents U.S. Treasury notes and bonds with a Moody's Investors Service rating of Aaa and Government Agency Bonds with a Moody's Investors Service rating of A1 or higher. (C) This category represents units of participation in a commingled fund that primarily invested in stocks of international companies and emerging markets. (In millions) December 31, 2020 Level 1 Level 2 Net Asset Value (A) Common stocks $ 252.3 $ 252.3 $ — $ — U.S. Treasury notes and bonds (B) 134.3 134.3 — — Mortgage- and asset-backed securities 29.3 — 29.3 — Corporate fixed income and other securities 116.6 — 116.6 — Commingled fund (C) 25.4 — — 25.4 Foreign government bonds 4.6 — 4.6 — U.S. municipal bonds 1.8 — 1.8 — Money market fund 8.8 — — 8.8 Mutual fund 9.2 9.2 — — Preferred stocks 0.6 0.6 — — U.S. Treasury Futures: Cash collateral 0.7 0.7 — — Forward contracts: Receivable (foreign currency) 0.1 — 0.1 — Total Pension Plan investments 583.7 $ 397.1 $ 152.4 $ 34.2 Receivable from broker for securities sold 0.2 Interest and dividends receivable 2.2 Payable to broker for securities purchased (15.8) Total OGE Energy Pension Plan assets $ 570.3 Pension Plan investments attributable to affiliates (150.0) Total OG&E Pension Plan assets $ 420.3 (A) GAAP allows the measurement of certain investments that do not have a readily determinable fair value at the net asset value. These investments do not consider the observability of inputs; therefore, they are not included within the fair value hierarchy. (B) This category represents U.S. Treasury notes and bonds with a Moody's Investors Service rating of Aaa and Government Agency Bonds with a Moody's Investors Service rating of A1 or higher.

Report of Business Segments (Ta

Report of Business Segments (Tables)	12 Months Ended
	Dec. 31, 2021
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment [Table Text Block]	The following tables present the results of OGE Energy's business segments for the years ended December 31, 2021, 2020 and 2019. 2021 Electric Utility Natural Gas Midstream Operations Other Eliminations Total (In millions) Operating revenues $ 3,653.7 $ — $ — $ — $ 3,653.7 Fuel, purchased power and direct transmission expense 2,127.6 — — — 2,127.6 Other operation and maintenance 464.7 1.6 (3.2) — 463.1 Depreciation and amortization 416.0 — — — 416.0 Taxes other than income 99.3 0.2 3.3 — 102.8 Operating income (loss) 546.1 (1.8) (0.1) — 544.2 Equity in earnings of unconsolidated affiliates — 169.8 — — 169.8 Gain on Enable/Energy Transfer transaction, net — 344.4 — — 344.4 Other income (expense) 7.7 (26.4) (2.0) (0.9) (21.6) Interest expense 152.0 — 7.2 (0.9) 158.3 Income tax expense (benefit) 41.8 101.0 (1.6) — 141.2 Net income (loss) $ 360.0 $ 385.0 $ (7.7) $ — $ 737.3 Total assets $ 11,688.0 $ 786.6 $ 350.3 $ (218.5) $ 12,606.4 Capital expenditures $ 778.5 $ — $ — $ — $ 778.5 2020 Electric Utility Natural Gas Midstream Operations Other Eliminations Total (In millions) Operating revenues $ 2,122.3 $ — $ — $ — $ 2,122.3 Fuel, purchased power and direct transmission expense 644.6 — — — 644.6 Other operation and maintenance 464.4 1.7 (3.3) — 462.8 Depreciation and amortization 391.3 — — — 391.3 Taxes other than income 97.2 0.4 3.8 — 101.4 Operating income (loss) 524.8 (2.1) (0.5) — 522.2 Equity in losses of unconsolidated affiliates (A) — (668.0) — — (668.0) Other income (expense) 4.1 (2.9) 3.6 (1.6) 3.2 Interest expense 154.8 — 5.3 (1.6) 158.5 Income tax expense (benefit) 34.7 (158.0) (4.1) — (127.4) Net income (loss) $ 339.4 $ (515.0) $ 1.9 $ — $ (173.7) Investment in unconsolidated affiliates $ — $ 374.3 $ — $ — $ 374.3 Total assets $ 10,489.0 $ 378.1 $ 116.4 $ (264.7) $ 10,718.8 Capital expenditures $ 650.5 $ — $ — $ — $ 650.5 (A) In March 2020, OGE Energy recorded a $780.0 million impairment on its investment in Enable, as further discussed in Notes 5 and 7. 2019 Electric Utility Natural Gas Midstream Operations Other Eliminations Total (In millions) Operating revenues $ 2,231.6 $ — $ — $ — $ 2,231.6 Fuel, purchased power and direct transmission expense 786.9 — — — 786.9 Other operation and maintenance 492.5 2.8 (3.5) — 491.8 Depreciation and amortization 355.0 — — — 355.0 Taxes other than income 89.5 0.4 3.7 — 93.6 Operating income (loss) 507.7 (3.2) (0.2) — 504.3 Equity in earnings of unconsolidated affiliates — 113.9 — — 113.9 Other income (expense) 3.1 (8.6) 2.2 (3.6) (6.9) Interest expense 140.5 — 11.0 (3.6) 147.9 Income tax expense (benefit) 20.1 20.7 (11.0) — 29.8 Net income $ 350.2 $ 81.4 $ 2.0 $ — $ 433.6 Investment in unconsolidated affiliates $ — $ 1,132.9 $ — $ — $ 1,132.9 Total assets $ 10,076.6 $ 1,135.4 $ 107.0 $ (294.7) $ 11,024.3 Capital expenditures $ 635.5 $ — $ — $ — $ 635.5

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Unrecorded Unconditional Purchase Obligations Disclosure [Table Text Block]	The following table presents the Registrants' future purchase obligations and commitments estimated for the next five years. (In millions) 2022 2023 2024 2025 2026 Total Purchase obligations and commitments: Minimum purchase commitments $ 97.7 $ 50.4 $ 31.2 $ 24.6 $ 24.6 $ 228.5 Expected wind purchase commitments 55.6 56.0 56.6 56.9 57.4 282.5 Long-term service agreement commitments 2.7 2.6 15.0 24.4 9.7 54.4 Total purchase obligations and commitments $ 156.0 $ 109.0 $ 102.8 $ 105.9 $ 91.7 $ 565.4
Schedule of Wind Power Purchases [Table Text Block]	The following table presents OG&E's wind power purchase contracts. Company Location Original Term of Contract Expiration of Contract MWs CPV Keenan Woodward County, OK 20 years 2030 152.0 Edison Mission Energy Dewey County, OK 20 years 2031 130.0 NextEra Energy Blackwell, OK 20 years 2032 60.0 The following table presents a summary of OG&E's wind power purchases for the years ended December 31, 2021, 2020 and 2019. Year Ended December 31 (In millions) 2021 2020 2019 CPV Keenan $ 27.3 $ 27.5 $ 27.2 Edison Mission Energy 21.7 22.8 23.1 NextEra Energy 6.8 7.0 7.4 Total wind power purchased $ 55.8 $ 57.3 $ 57.7

Schedule II (Tables)

Schedule II (Tables)	12 Months Ended
	Dec. 31, 2021
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Schedule II Valuation and Qualifying Accounts [Table Text Block]	SCHEDULE II - Valuation and Qualifying Accounts Additions Description Balance at Beginning of Period Charged to Costs and Expenses Deductions (A) Balance at End of Period (In millions) Balance at December 31, 2019 Reserve for Uncollectible Accounts $ 1.7 $ 2.2 $ 2.4 $ 1.5 Balance at December 31, 2020 Reserve for Uncollectible Accounts $ 1.5 $ 3.0 $ 1.9 $ 2.6 Balance at December 31, 2021 Reserve for Uncollectible Accounts $ 2.6 $ 3.2 $ 3.4 $ 2.4

Summary of Significant Accoun_4

Summary of Significant Accounting Policies Regulated Operations (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2021	Dec. 02, 2021	Dec. 31, 2020
Schedule of Regulatory Assets and Liabilities [Line Items]
Fuel clause under recoveries		$ 151.9		$ 0
Fuel clause over recoveries		0		28.6
Regulatory Assets, Current		182.6		19.8
Regulatory Assets, Noncurrent		1,230.8		415.6
Regulatory Liability, Current		2.5		35.1
Regulatory Liability, Noncurrent		1,231.1		1,188.9
Prior Period Reclassification Adjustment		$ 23.1
Investment Owned, Balance, Shares		95,389,721	110,982,805
Income taxes recoverable from customers, net [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Regulatory Liability, Noncurrent		$ 930.7		867.4
Accrued removal obligations [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Regulatory Liability, Noncurrent		296.8		316.8
Other Regulatory Liabilities [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Regulatory Liability, Current	[1]	2.5		6.5
Regulatory Liability, Noncurrent		3.6		4.7
Oklahoma demand program rider under recovery [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Regulatory Assets, Current	[2]	11.7		0
SPP cost tracker under recovery [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Regulatory Assets, Current	[2]	9.3		7
Benefit obligations regulatory asset [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Regulatory Assets, Noncurrent		109.2		164.9
Deferred storm expenses [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Regulatory Assets, Noncurrent		172.8		158.8
Smart Grid [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Regulatory Assets, Noncurrent		3.9		11.2
Unamortized loss on reacquired debt [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Regulatory Assets, Noncurrent		8.9		9.7
Deferred Pension Expenses [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Regulatory Assets, Noncurrent		12.1		9.3
Dry Scrubber Regulatory Asset [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Regulatory Assets, Noncurrent		18.9		19.7
Other Regulatory Assets [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Regulatory Assets, Current	[2]	8.7		8.4
Regulatory Assets, Noncurrent		10.4		11.1
Pension tracker [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Regulatory Assets, Noncurrent		42.9		18.1
Frontier Plant
Schedule of Regulatory Assets and Liabilities [Line Items]
Regulatory Assets, Noncurrent		6.7		6.4
COVID-19 Impact
Schedule of Regulatory Assets and Liabilities [Line Items]
Regulatory Assets, Noncurrent		8.2		6.4
Generation Capacity Replacement rider
Schedule of Regulatory Assets and Liabilities [Line Items]
Regulatory Assets, Current	[2]	1		4.4
Winter Storm Uri Costs | OKLAHOMA
Schedule of Regulatory Assets and Liabilities [Line Items]
Regulatory Assets, Noncurrent		747.9		0
Winter Storm Uri Costs | ARKANSAS
Schedule of Regulatory Assets and Liabilities [Line Items]
Regulatory Assets, Noncurrent		$ 88.9		$ 0
[1]	Included in Other Current Liabilities in the balance sheets.
[2]	Included in Other Current Assets in the balance sheets.

Summary of Significant Accoun_5

Summary of Significant Accounting Policies Accounting Records (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Regulatory Assets, Current	$ 182.6	$ 19.8
Regulatory Assets, Noncurrent	1,230.8	415.6
Deferred Storm and Property Reserve Deficiency, Current	2.7
Regulatory Liability, Current	2.5	35.1
Pension Plans, Defined Benefit [Member] | Defined Benefit Plans Income Loss [Member]
Components of Benefit Obligation Regulatory Asset	89.6	147.3
Other Postretirement Benefit Plans, Defined Benefit [Member] | Defined Benefit Plans Income Loss [Member]
Components of Benefit Obligation Regulatory Asset	23.2	26.2
Other Postretirement Benefit Plans, Defined Benefit [Member] | Prior Service Cost [Member]
Components of Benefit Obligation Regulatory Asset	$ (3.6)	$ (8.6)

Summary of Significant Accoun_6

Summary of Significant Accounting Policies Allowance for Uncollectible Accounts Receivable (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Allowance for Doubtful Accounts Receivable	$ 2.4	$ 2.6

Summary of Significant Accoun_7

Summary of Significant Accounting Policies Fuel Inventories (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Other	$ 73.3	$ 41.2
OG&E [Member]
Fuel inventories	40.6	36.5
Other	67.7	36.9
Public Utilities, Inventory, Fuel [Member]
Fuel inventories	$ 40.6	$ 36.5

Summary of Significant Accoun_8

Summary of Significant Accounting Policies Property, Plant and Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021		Dec. 31, 2020		Dec. 31, 2019
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	$ 14,151.8		$ 13,442.2
Accumulated Depreciation	4,318.9		4,067.6
Net property, plant and equipment	9,832.9		9,374.6
Public Utilities, Property, Plant and Equipment, Amount of Acquisition Adjustments, Related Accumulated Depreciation	$ 72.8		$ 67.3
Provision for Depreciation Rate	2.60%		2.60%
McClain Plant [Member]
Property, Plant and Equipment [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	77.00%	[1]	77.00%	[2]
Property, Plant and Equipment, Gross	$ 258.5	[1]	$ 257.1	[2]
Accumulated Depreciation	109	[1]	96	[2]
Net property, plant and equipment	149.5	[1]	161.1	[2]
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	$ 0.2		$ 0.1
Redbud Plant [Member]
Property, Plant and Equipment [Line Items]
Jointly Owned Utility Plant, Proportionate Ownership Share	51.00%	[1],[3]	51.00%	[2],[4]
Property, Plant and Equipment, Gross	$ 538.2	[1],[3]	$ 531.8	[2],[4]
Accumulated Depreciation	203.4	[1],[3]	181.9	[2],[4]
Net property, plant and equipment	334.8	[1],[3]	349.9	[2],[4]
Jointly Owned Utility Plant, Ownership Amount of Construction Work in Progress	0.2		1.8
Amount of Acquisition Adjustments	148.3		148.3
OGE Energy [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	6.1		6.1
Accumulated Depreciation	0		0
Net property, plant and equipment	6.1		6.1
OG&E [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	14,145.7		13,436.1
Accumulated Depreciation	4,318.9		4,067.6
Net property, plant and equipment	9,826.8		9,368.5
Capitalized Computer Software, Gross	103.7		89.7
Capitalized Computer Software, Amortization	18.1		14.9		$ 11
OG&E [Member] | Total Property Plant and Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	14,145.7		13,436.1
Accumulated Depreciation	4,318.9		4,067.6
Net property, plant and equipment	9,826.8		9,368.5
OG&E [Member] | Electric Transmission and Distribution [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	5,225.8		4,809.9
Accumulated Depreciation	1,477.5		1,422.1
Net property, plant and equipment	3,748.3		3,387.8
OG&E [Member] | Electric Generation Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	5,037.9	[5]	4,932.2	[6]
Accumulated Depreciation	1,839	[5]	1,713.6	[6]
Net property, plant and equipment	3,198.9	[5]	3,218.6	[6]
Amount of Acquisition Adjustments	148.3		148.3
Public Utilities, Property, Plant and Equipment, Amount of Acquisition Adjustments, Related Accumulated Depreciation	72.8		67.3
OG&E [Member] | Electric Transmission [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	3,038.2	[7]	2,944.6	[8]
Accumulated Depreciation	627	[7]	591.7	[8]
Net property, plant and equipment	2,411.2	[7]	2,352.9	[8]
Amount of Acquisition Adjustments	3.3		3.3
Public Utilities, Property, Plant and Equipment, Amount of Acquisition Adjustments, Related Accumulated Depreciation	0.9		0.9
OG&E [Member] | Finite-Lived Intangible Assets, Major Class Name [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	301.1		254.1
Accumulated Depreciation	171.7		153.9
Net property, plant and equipment	129.4		100.2
OG&E [Member] | Property, Plant and Equipment, Other Types [Member]
Property, Plant and Equipment [Line Items]
Property, Plant and Equipment, Gross	542.7		495.3
Accumulated Depreciation	203.7		186.3
Net property, plant and equipment	$ 339		$ 309
[1]	Construction work in progress was $0.2 million and $0.2 million for the McClain and Redbud Plants, respectively.
[2]	Construction work in progress was $0.1 million and $1.8 million for the McClain and Redbud Plants, respectively.
[3]	This amount includes a plant acquisition adjustment of $148.3 million and accumulated amortization of $72.8 million.
[4]	This amount includes a plant acquisition adjustment of $148.3 million and accumulated amortization of $67.3 million.
[5]	This amount includes a plant acquisition adjustment of $148.3 million and accumulated amortization of $72.8 million.
[6]	This amount includes a plant acquisition adjustment of $148.3 million and accumulated amortization of $67.3 million.
[7]	This amount includes a plant acquisition adjustment of $3.3 million and accumulated amortization of $0.9 million.
[8]	This amount includes a plant acquisition adjustment of $3.3 million and accumulated amortization of $0.9 million.

Summary of Significant Accoun_9

Summary of Significant Accounting Policies Depreciation and Amortization (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Provision for Depreciation Rate	2.60%	2.60%
Projected provision for depreciation in next fiscal year	2.60%
Percent Of Intangible Plant Balance Amortizable	99.10%
Percent of Intangible Plant Balance Amortizable Thereafter	0.90%
Transmission Equipment [Member] | OG&E [Member]
Amount of Acquisition Adjustments	$ 3.3
Redbud Plant [Member]
Amount of Acquisition Adjustments	$ 148.3	$ 148.3

Summary of Significant Accou_10

Summary of Significant Accounting Policies Asset Retirement Obligation (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance at January 1		$ 79.6	$ 73.5
Accretion expense		0.6	0.5
Revisions in estimated cash flows	[1]	0	5.8
Liabilities settled	[2]	0	(0.2)
Balance at December 31		$ 80.2	$ 79.6
[1]	Assumptions changed related to the estimated timing and estimated cost of the removal of asbestos at OG&E's generating facilities.
[2]	Asset retirement obligations were settled for asbestos removal at one of OG&E's generating facilities

Summary of Significant Accou_11

Summary of Significant Accounting Policies Enviromental Costs (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Accrued Environmental Loss Contingencies, Noncurrent	$ 25.8	$ 25

Summary of Significant Accou_12

Summary of Significant Accounting Policies Allowance for Funds Used During Construction (Details)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Public Utilities, Allowance for Funds Used During Construction, Rate	7.40%	7.30%	7.60%

Summary of Significant Accou_13

Summary of Significant Accounting Policies Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Accumulated other comprehensive (income) loss		$ (24.8)	$ (32.1)	$ (27.9)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax		0.9	(8.2)
Amounts reclassified from accumulated other comprehensive income (loss)		(1.6)	(3.9)	(3.4)
Amounts reclassified from accumulated other comprehensive income (loss)		0.4	2.1
Amounts Reclassified from Accumulated OCI, Net of Tax and Noncontrolling Interest		6.4	4
Other Comprehensive Income (Loss), Net of Tax		7.3	(4.2)	1
Settlement cost, net of tax of $2.7, $0.7 and $2.7, respectively		6	2.2	8.6
Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Amounts reclassified from accumulated other comprehensive income (loss)		(7.7)	(6.1)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax	[1]	(2.5)	(5.1)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, before Tax	[1]	(0.1)	0
Other Comprehensive Income (Loss), Defined Benefit Plan, Settlement and Curtailment Gain (Loss), before Tax	[1]	(8.7)	(2.9)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, before Tax		(11.3)	(8)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, Tax		(3.6)	(1.9)
Other Postretirement Benefits Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Amounts reclassified from accumulated other comprehensive income (loss)		1.3	2.1
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax	[1]	0.1	(0.1)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, before Tax	[1]	1.8	2.3
Other Comprehensive Income (Loss), Defined Benefit Plan, Settlement and Curtailment Gain (Loss), before Tax	[1]	0	0.4
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, before Tax		1.7	2.8
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, Tax		0.4	0.7
Defined Benefit Plans Income Loss [Member] | Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Accumulated other comprehensive income (loss)		(24.9)	(33.9)	(34.9)
Other comprehensive income before reclassifications		1.4	(5.1)
Amounts reclassified from accumulated other comprehensive income (loss)		1.6	3.9
Other Comprehensive Income (Loss), Net of Tax		9	1
Defined Benefit Plans Income Loss [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Accumulated other comprehensive income (loss)		0.8	1.4	4.2
Other comprehensive income before reclassifications		(0.7)	(2.4)
Amounts reclassified from accumulated other comprehensive income (loss)		0.1	(0.1)
Other Comprehensive Income (Loss), Net of Tax		(0.6)	(2.8)
AOCI Attributable to Parent [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Other Comprehensive Income (Loss), Net of Tax		7.3	(4.2)	1
Defined Benefit Plan Prior Service Cost [Member] | Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Accumulated other comprehensive income (loss)		(1.2)	(0.2)	(0.2)
Other comprehensive income before reclassifications		(1.1)	0
Amounts reclassified from accumulated other comprehensive income (loss)		0.1	0
Other Comprehensive Income (Loss), Net of Tax		(1)	0
Defined Benefit Plan Prior Service Cost [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Accumulated other comprehensive income (loss)		0.5	1.9	3.6
Other comprehensive income before reclassifications		0	0
Amounts reclassified from accumulated other comprehensive income (loss)		(1.4)	(1.7)
Other Comprehensive Income (Loss), Net of Tax		(1.4)	(1.7)
Settlement Cost [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Settlement cost, net of tax of $2.7, $0.7 and $2.7, respectively		6	2.2
Settlement Cost [Member] | Defined Benefit Plans Income Loss [Member] | Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Settlement cost, net of tax of $2.7, $0.7 and $2.7, respectively		6	2.2
Settlement Cost [Member] | Defined Benefit Plans Income Loss [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Settlement cost, net of tax of $2.7, $0.7 and $2.7, respectively		0	0
Settlement Cost [Member] | Defined Benefit Plan Prior Service Cost [Member] | Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Settlement cost, net of tax of $2.7, $0.7 and $2.7, respectively		0	0
Settlement Cost [Member] | Defined Benefit Plan Prior Service Cost [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Settlement cost, net of tax of $2.7, $0.7 and $2.7, respectively		0	0
Curtailment
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Settlement cost, net of tax of $2.7, $0.7 and $2.7, respectively			(0.3)
Curtailment | Defined Benefit Plans Income Loss [Member] | Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Settlement cost, net of tax of $2.7, $0.7 and $2.7, respectively			0
Curtailment | Defined Benefit Plans Income Loss [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Settlement cost, net of tax of $2.7, $0.7 and $2.7, respectively			(0.3)
Curtailment | Defined Benefit Plan Prior Service Cost [Member] | Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Settlement cost, net of tax of $2.7, $0.7 and $2.7, respectively			0
Curtailment | Defined Benefit Plan Prior Service Cost [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Settlement cost, net of tax of $2.7, $0.7 and $2.7, respectively			0
Commodity Contract [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax		1.3	(0.7)
Amounts reclassified from accumulated other comprehensive income (loss)		0	0
Net current period other comprehensive income (loss)		1.3	(0.7)
AOCI, Derivative Qualifying as Hedge, Excluded Component, after Tax		0	(1.3)	$ (0.6)
Commodity Contract [Member] | Settlement Cost [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Settlement cost, net of tax of $2.7, $0.7 and $2.7, respectively		$ 0	0
Commodity Contract [Member] | Curtailment
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Settlement cost, net of tax of $2.7, $0.7 and $2.7, respectively			$ 0
[1]	These accumulated other comprehensive income (loss) components are included in the computation of net periodic benefit cost (see Note 13 for additional information).

Summary of Significant Accou_14

Summary of Significant Accounting Policies Summary of Significant Accounting Policies Reclassifications (Details) $ in Millions	12 Months Ended
	Dec. 31, 2021USD ($)
Prior Period Reclassification Adjustment	$ 23.1

Revenue from Contracts with C_3

Revenue from Contracts with Customers (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021		Dec. 31, 2020	Dec. 31, 2019
Revenue from Contract with Customer, Excluding Assessed Tax	$ 3,588.7	[1]	$ 2,069.8	$ 2,175.5
Provision for Rate Refund [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	0		3.8	(0.9)
Integrated Market [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	468.9		49.6	38.4
Transmission [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	140.2		143.3	148
Other Contracts with Customers [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	1.1		30.7	29.1
Residential [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	1,309.1		842.7	865.8
Commercial [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	749.2		465.6	486.6
Industrial [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	323		192.6	217.8
Oilfield [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	312.8		169.2	200.4
Public Authority [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	284.4		172.3	190.3
Total Retail Customer [Member]
Revenue from Contract with Customer, Excluding Assessed Tax	$ 2,978.5		$ 1,842.4	$ 1,960.9
[1]	In February 2021, Winter Storm Uri resulted in record winter peak demand for electricity and extremely high natural gas and purchased power prices in OG&E's service territory. Operating revenues significantly increased due to increased fuel, purchased power and direct transmission expenses, which are generally recoverable from customers, as a result of Winter Storm Uri. For further discussion, see Note 16 and "Item 7. Management's Discussion and Analysis of Financial Condition and Results of Operations."

Leases, Codification Topic 84_2

Leases, Codification Topic 842 (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Lessee, Operating Lease, Contingent Liability		$ 6.8
Operating Lease, Cost		6.3	$ 6.4	$ 6
Operating Leased Assets [Line Items]
Cash Paid on Operating Leases		6.3	6.4	5.6
Operating Lease, Right-of-Use Asset	[1]	33	37.6
Operating Lease, Liability	[2]	$ 37.6	$ 42.3
Operating Lease, Weighted Average Remaining Lease Term		12 years 2 months 12 days	12 years 6 months
Operating Lease, Weighted Average Discount Rate, Percent		3.90%	3.90%
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability		$ 0	$ 1.4	10.7
Lessee, Operating Lease, Liability, Payments, Due Next Twelve Months		5.7
Lessee, Operating Lease, Liability, Payments, Due Year Two		5.1
Lessee, Operating Lease, Liability, Payments, Due Year Three		3.1
Lessee, Operating Lease, Liability, Payments, Due Year Four		3
Lessee, Operating Lease, Liability, Payments, Due Year Five		3
Lessee, Operating Lease, Liability, Payments, Due after Year Five		28.7
Lessee, Operating Lease, Liability, Payments, Due		48.6
Lessee, Operating Lease, Liability, Undiscounted Excess Amount		11
Lessee, Operating Lease, Contingent Liability		6.8
Operating Lease, Cost		6.3	6.4	6
Og and E [Member]
Leases [Abstract]
Operating Lease, Cost		5.7	5.5	5.1
Operating Leased Assets [Line Items]
Cash Paid on Operating Leases		5.7	5.5	4.8
Operating Lease, Right-of-Use Asset	[1]	33	37
Operating Lease, Liability	[2]	$ 37.6	$ 41.7
Operating Lease, Weighted Average Remaining Lease Term		12 years 2 months 12 days	12 years 8 months 12 days
Operating Lease, Weighted Average Discount Rate, Percent		3.90%	3.90%
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability		$ 0	$ 1.4	10.7
Lessee, Operating Lease, Liability, Payments, Due Next Twelve Months		5.7
Lessee, Operating Lease, Liability, Payments, Due Year Two		5.1
Lessee, Operating Lease, Liability, Payments, Due Year Three		3.1
Lessee, Operating Lease, Liability, Payments, Due Year Four		3
Lessee, Operating Lease, Liability, Payments, Due Year Five		3
Lessee, Operating Lease, Liability, Payments, Due after Year Five		28.7
Lessee, Operating Lease, Liability, Payments, Due		48.6
Lessee, Operating Lease, Liability, Undiscounted Excess Amount		11
Operating Lease, Cost		$ 5.7	$ 5.5	$ 5.1
[1]	Included in Property, Plant and Equipment in the Registrants' balance sheets.
[2]	Included in Other Deferred Credits and Other Liabilities in the Registrants' balance sheets.

Investment in Unconsolidated _3

Investment in Unconsolidated Affiliate (Details) - USD ($) $ / shares in Units, $ in Millions		11 Months Ended		12 Months Ended
		Dec. 02, 2021		Dec. 31, 2021	Dec. 31, 2020		Dec. 31, 2019		Jun. 30, 2021	May 01, 2013
Schedule of Equity Method Investments [Line Items]
Limited Liability Company or Limited Partnership, Members or Limited Partners, Ownership Interest		25.50%			25.50%		25.50%
Distribution Made to Limited Partner, Distributions Declared, Per Unit				$ 0.175
Equity in earnings (losses) of unconsolidated affiliates		$ 169.8	[1]	$ 169.8	$ (668)	[1],[2]	$ 113.9	[1]
Share Price									$ 33.65
Investment Owned, Balance, Shares		110,982,805		95,389,721
Equity Method Investment, Other than Temporary Impairment	[3]	$ 0			(780)		0
Gain (Loss) on Disposition of Assets				$ 344.4	0		0
Proceeds from Sales of Assets, Investing Activities				35
fees paid from disposition of assets				8.6
Enable Midstream Partners [Member]
Schedule of Equity Method Investments [Line Items]
Distributions received				$ 73.4	91.7		144
Enogex LLC [Member]
Schedule of Equity Method Investments [Line Items]
Increase in fair value of net assets										$ 2,200
OGE Holdings [Member]
Schedule of Equity Method Investments [Line Items]
Limited Liability Company or Limited Partnership, Members or Limited Partners, Ownership Interest				25.50%
CenterPoint [Member]
Schedule of Equity Method Investments [Line Items]
Proceeds from Sales of Assets, Investing Activities				$ 30
Energy Transfer
Schedule of Equity Method Investments [Line Items]
Proceeds from Sales of Assets, Investing Activities				5
Natural Gas Midstream Operations [Member]
Schedule of Equity Method Investments [Line Items]
Equity in earnings (losses) of unconsolidated affiliates				169.8	$ (668)	[2]	$ 113.9
Gain (Loss) on Disposition of Assets				$ 344.4
[1]	For the year ended December 31, 2020, Enable recorded a $225.0 million impairment on its SESH equity method investment. Enable estimated the fair value of this equity method investment was below the carrying value at September 30, 2020 and concluded the decline in value was other than temporary due to the expiration of a transportation contract and the current status of renewal negotiations. The impairment ran through OGE Energy's portion of Enable net income and was offset by basis differences that flow through the amortization of basis difference and dilution recognition line item above
[2]	In March 2020, OGE Energy recorded a $780.0 million impairment on its investment in Enable, as further discussed in Notes 5 and 7.
[3]	Effective March 31, 2020, OGE Energy estimated the fair value of its investment in Enable was below the book value and concluded the decline in value was not temporary due to the severity of the decline and recent rapid deterioration, as well as the near term future outlook, of the midstream oil and gas industry. Accordingly, OGE Energy recorded a $780.0 million impairment on its investment in Enable in 2020. Further information concerning the fair value method used to measure the impairment on OGE Energy's investment in Enable can be found in Note 7.

Investment in Unconsolidated _4

Investment in Unconsolidated Affiliate Summarized Balance Sheet Information of Equity Method Investment (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 02, 2021	Dec. 31, 2020
Summarized Financial Information of Equity Method Investment [Line Items]
Assets, Current	$ 613.6		$ 428.5
Liabilities, Current	$ 1,089.6		697.4
Equity Method Investment, Nonconsolidated Investee or Group of Investees [Member]
Summarized Financial Information of Equity Method Investment [Line Items]
Assets, Current		$ 594	381
Assets, Noncurrent		11,227	11,348
Liabilities, Current		1,254	582
Liabilities, Noncurrent		$ 3,281	$ 4,052

Investment in Unconsolidated _5

Investment in Unconsolidated Affiliate Summarized Income Statement of Equity Method Investment (Details) - USD ($) $ in Millions	11 Months Ended	12 Months Ended
	Dec. 02, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Schedule of Equity Method Investments [Line Items]
Equity Method Investment, Summarized Financial Information, Operating Income	$ 634		$ 465	$ 569
Operating revenues		$ 3,653.7	2,122.3	2,231.6
Net income (loss)		$ 737.3	(173.7)	433.6
Equity Method Investment, Nonconsolidated Investee or Group of Investees [Member]
Schedule of Equity Method Investments [Line Items]
Operating revenues	3,466		2,463	2,960
Cost of Revenue	1,959		965	1,279
Net income (loss)	$ 461		$ 52	$ 360

Investment in Unconsolidated _6

Investment in Unconsolidated Affiliate Reconciliation of Equity in Earnings of Unconsolidated Affiliates (Details) - USD ($) $ in Millions		11 Months Ended		12 Months Ended
		Dec. 02, 2021		Dec. 31, 2021	Dec. 31, 2020		Dec. 31, 2019
Schedule of Equity Method Investments [Line Items]
Timing Differences Related to Equity Method Investee Net Income		$ 9			$ 0		$ 0
Limited Liability Company or Limited Partnership, Members or Limited Partners, Ownership Interest		25.50%			25.50%		25.50%
Proportionate Unconsolidated Affiliate Net Income		$ 119.8			$ 13.2		$ 91.8
Amortization of basis difference and dilution recognition	[1]	50			98.8		22.1
Equity Method Investment, Other than Temporary Impairment	[2]	0			780		0
Equity in earnings of unconsolidated affiliates		169.8	[3]	$ 169.8	(668)	[3],[4]	113.9	[3]
Net income (loss)				737.3	(173.7)		433.6
Equity Method Investment, Nonconsolidated Investee or Group of Investees [Member]
Schedule of Equity Method Investments [Line Items]
Equity in earnings of unconsolidated affiliates		470			52		360
Net income (loss)		$ 461			52		360
Natural Gas Midstream Operations [Member]
Schedule of Equity Method Investments [Line Items]
Equity in earnings of unconsolidated affiliates				169.8	(668)	[4]	113.9
Net income (loss)				$ 385	$ (515)		$ 81.4
OGE Holdings [Member]
Schedule of Equity Method Investments [Line Items]
Limited Liability Company or Limited Partnership, Members or Limited Partners, Ownership Interest				25.50%
[1]	Includes loss on dilution, net of proportional basis difference recognition.
[2]	Effective March 31, 2020, OGE Energy estimated the fair value of its investment in Enable was below the book value and concluded the decline in value was not temporary due to the severity of the decline and recent rapid deterioration, as well as the near term future outlook, of the midstream oil and gas industry. Accordingly, OGE Energy recorded a $780.0 million impairment on its investment in Enable in 2020. Further information concerning the fair value method used to measure the impairment on OGE Energy's investment in Enable can be found in Note 7.
[3]	For the year ended December 31, 2020, Enable recorded a $225.0 million impairment on its SESH equity method investment. Enable estimated the fair value of this equity method investment was below the carrying value at September 30, 2020 and concluded the decline in value was other than temporary due to the expiration of a transportation contract and the current status of renewal negotiations. The impairment ran through OGE Energy's portion of Enable net income and was offset by basis differences that flow through the amortization of basis difference and dilution recognition line item above
[4]	In March 2020, OGE Energy recorded a $780.0 million impairment on its investment in Enable, as further discussed in Notes 5 and 7.

Related Party Disclosures (Deta

Related Party Disclosures (Details) - USD ($) $ in Millions	11 Months Ended	12 Months Ended
	Dec. 02, 2021	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Related Party Transaction [Line Items]
Expected Settlement Charge		$ 19.4
Excluding Fuel Purchases [Member]
Related Party Transaction [Line Items]
Accounts receivable - unconsolidated affiliates		0.3	$ 2
Og and E [Member]
Related Party Transaction [Line Items]
Dividends, Common Stock		(265)		$ (325)
Og and E [Member] | Retained Earnings
Related Party Transaction [Line Items]
Dividends, Common Stock		265	0	325
Enable Midstream Partners [Member] | Og and E [Member]
Related Party Transaction [Line Items]
Revenue from Related Parties	$ 13.3		15.1	15.9
Enable Midstream Partners [Member] | Og and E [Member] | Natural Gas Transportation [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Purchases from Related Party	32.7		32.8	41.2
Enable Midstream Partners [Member] | Og and E [Member] | Natural Gas Purchases [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Purchases from Related Party	$ (33.5)		2.7	(6)
Enable Midstream Partners [Member] | OGE Energy [Member] | Operating Costs Charged [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Selling, General and Administrative Expenses from Transactions with Related Party		0.3	0.4	0.5
Enable Midstream Partners [Member] | OGE Energy [Member] | Employment Costs [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Selling, General and Administrative Expenses from Transactions with Related Party		12.2	17.3	23.2
Og and E [Member] | OGE Energy [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Selling, General and Administrative Expenses from Transactions with Related Party		$ 139.3	$ 140.6	$ 149.8

Fair Value Measurements Carryin

Fair Value Measurements Carrying and Fair Value Amounts (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total long-term debt	$ 4,496.4	$ 3,494.4
Redeemable Noncontrolling Interest, Equity, Carrying Amount	785.1
Equity Securities, FV-NI, Current	785.1	0
OG&E Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total long-term debt	3,851.8	3,349.6
Long-Term Debt, Fair Value	4,460.2	4,182.1
OG&E Industrial Authority Bonds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total long-term debt	135.4	135.4
Long-Term Debt, Fair Value	135.4	135.4
OG&E Tinker Debt [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total long-term debt	9.3	9.4
Long-Term Debt, Fair Value	10	10.7
OGE Energy Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Total long-term debt	499.9	0
Long-Term Debt, Fair Value	497.8	0
Fair Value, Measurements, Recurring [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Derivative Assets (Liabilities), at Fair Value, Net	$ 0	$ 0

Stock Based Compensation (Detai

Stock Based Compensation (Details) - USD ($) $ / shares in Units, $ in Millions		Sep. 30, 2020	Mar. 31, 2020	Dec. 31, 2021		Dec. 31, 2020	Dec. 31, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of Shares Authorized				7,400,000
Tax Benefit from Compensation Expense				$ 2.5		$ 2.5	$ 3.6
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted				154,523		247,252
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted				154,523		247,252
Minimum payout range				0.00%
Maximum payout range				200.00%
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted				154,523		247,252
Total Compensation Cost Not yet Recognized				$ 11
Treasury Stock, Shares, Acquired				405,000
Treasury Stock Acquired, Average Cost Per Share		$ 33.14	$ 38.04
Share-based Compensation Arrangement by Share-based Payment Award, Shares Issued in Period							443,900
Og and E [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Tax Benefit from Compensation Expense				$ 0.6		$ 0.8	$ 1.3
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Total Compensation Cost Not yet Recognized				$ 2.8
Stock Issued During Period, Shares, New Issues				0		0	0
Performance Units Related to Earnings Per Share [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted				0
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number				0		79,002
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted				0
Equity Instruments Other than Options, Converted in Period	[1]			(79,002)
Equity Instruments Other than Options, Forfeited in Period				0
Awards Other than Options, Fully Vested				0
Equity Instruments Other than Options, Converted, Aggregrate Intrinsic Value				$ 2.7
Equity Instruments Other than Options, Vested in Period, Aggregate Intrinsic Value				0
Equity Instruments Other than Options, Outstanding, Aggregrate Intrinsic Value				$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted				0
Equity Instruments Other than Options, Forfeited in Period				0
Fair Value of Vested Performance Units and Restricted Stock				$ 0		$ 2.5	$ 5.2
Performance Units Related to Earnings Per Share [Member] | Og and E [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted				0
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number				0		25,235
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted				0
Equity Instruments Other than Options, Converted in Period	[1]			(25,235)
Equity Instruments Other than Options, Forfeited in Period				0
Equity Other Than Options, Employee Migration	[2]			0
Awards Other than Options, Fully Vested				0
Equity Instruments Other than Options, Converted, Aggregrate Intrinsic Value				$ 0.8
Equity Instruments Other than Options, Vested in Period, Aggregate Intrinsic Value				0
Equity Instruments Other than Options, Outstanding, Aggregrate Intrinsic Value				$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted				0
Equity Instruments Other than Options, Forfeited in Period				0
Equity Other Than Options, Employee Migration	[2]			0
Fair Value of Vested Performance Units and Restricted Stock				$ 0		$ 0.8	$ 0.9
Total Shareholder Return [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted				249,909	[3]	201,552	208,647
Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value				$ 38.14		$ 38.03	$ 47
Expected Dividend Rate				4.70%		3.50%	4.00%
Expected Volatility Rate				29.00%		15.00%	17.00%
Risk Free Interest Rate				0.22%		1.17%	2.47%
Expected Term				2 years 10 months 2 days		2 years 10 months 6 days	2 years 10 months 9 days
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number				581,252		612,262
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted				249,909	[3]	201,552	208,647
Equity Instruments Other than Options, Converted in Period	[1]			(236,990)
Equity Instruments Other than Options, Forfeited in Period				(43,929)
Awards Other than Options, Fully Vested				172,748
Equity Instruments Other than Options, Converted, Aggregrate Intrinsic Value				$ 5.4
Equity Instruments Other than Options, Vested in Period, Aggregate Intrinsic Value				0
Equity Instruments Other than Options, Outstanding, Aggregrate Intrinsic Value				$ 17.5
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Equity Instruments Other than Options, Nonvested, Number, Beginning Balance				375,272
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted				249,909	[3]	201,552	208,647
Equity Instruments Other than Options, Vested in Period				(172,748)
Equity Instruments Other than Options, Forfeited in Period				(43,929)
Equity Instruments Other than Options, Nonvested, Number, Ending Balance				408,504		375,272
Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value				$ 38.05		$ 42.51
Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value				38.14		$ 38.03	$ 47
Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value				47
Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value				$ 41.02
Fair Value of Vested Performance Units and Restricted Stock				$ 8.1		$ 8.7	$ 9.3
Total Compensation Cost Not yet Recognized				$ 7.5
Total Compensation Cost Not yet Recognized, Period for Recognition				1 year 8 months 15 days
Total Shareholder Return [Member] | Og and E [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted				68,720	[4]	67,975	68,396
Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value				$ 38.14		$ 38.03	$ 47
Expected Dividend Rate				4.70%		3.50%	4.00%
Expected Volatility Rate				29.00%		15.00%	17.00%
Risk Free Interest Rate				0.22%		1.17%	2.47%
Expected Term				2 years 10 months 6 days		2 years 10 months 6 days	2 years 10 months 9 days
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number				161,310		182,363
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted				68,720	[4]	67,975	68,396
Equity Instruments Other than Options, Converted in Period	[1]			(75,693)
Equity Instruments Other than Options, Forfeited in Period				(14,132)
Equity Other Than Options, Employee Migration	[5]			52
Awards Other than Options, Fully Vested				48,195
Equity Other Than Options, Employee Migration, Weighted Average Grant Date Fair Value				$ 41.01
Equity Instruments Other than Options, Converted, Aggregrate Intrinsic Value				$ 1.7
Equity Instruments Other than Options, Vested in Period, Aggregate Intrinsic Value				0
Equity Instruments Other than Options, Outstanding, Aggregrate Intrinsic Value				$ 4.8
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Equity Instruments Other than Options, Nonvested, Number, Beginning Balance				106,670
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted				68,720	[4]	67,975	68,396
Equity Instruments Other than Options, Vested in Period				(48,195)
Equity Instruments Other than Options, Forfeited in Period				(14,132)
Equity Other Than Options, Employee Migration	[5]			52
Equity Instruments Other than Options, Nonvested, Number, Ending Balance				113,115		106,670
Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value				$ 38.10		$ 42.49
Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value				38.14		$ 38.03	$ 47
Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value				47
Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value				$ 41.12
Fair Value of Vested Performance Units and Restricted Stock				$ 2.3		$ 2.8	$ 3.2
Total Compensation Cost Not yet Recognized				$ 2
Total Compensation Cost Not yet Recognized, Period for Recognition				1 year 8 months 19 days
Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation Expense				$ 7.5		8.9	13
Performance Shares [Member] | Og and E [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation Expense				1.8		2.6	4.5
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation Expense				$ 2.3		$ 0.9	$ 0.9
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted				89,197		67,193	75,929
Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value				$ 31.11		$ 43.69	$ 41.71
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number				133,671		124,919
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted				89,197		67,193	75,929
Equity Instruments Other than Options, Forfeited in Period				(27,171)
Awards Other than Options, Fully Vested				47,907
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value				$ (2.2)
Equity Instruments Other than Options, Vested in Period, Aggregate Intrinsic Value				(2)
Equity Instruments Other than Options, Outstanding, Aggregrate Intrinsic Value				$ 5.1
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Equity Instruments Other than Options, Nonvested, Number, Beginning Balance				124,919
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted				89,197		67,193	75,929
Equity Instruments Other than Options, Vested in Period				(53,274)
Equity Instruments Other than Options, Forfeited in Period				(27,171)
Equity Instruments Other than Options, Nonvested, Number, Ending Balance				133,671		124,919
Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value				$ 35.64		$ 42.69
Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value				31.11		$ 43.69	$ 41.71
Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value				41.59
Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value				$ 42.37
Fair Value of Vested Performance Units and Restricted Stock				$ 2.2		$ 0.1	$ 0.1
Total Compensation Cost Not yet Recognized				$ 3.5
Total Compensation Cost Not yet Recognized, Period for Recognition				1 year 5 months 23 days
Restricted Stock [Member] | Og and E [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation Expense				$ 0.4		$ 0.4	$ 0.4
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted				22,911		22,665	26,141
Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value				$ 30.91		$ 43.69	$ 41.63
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number				35,613		34,130
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted				22,911		22,665	26,141
Equity Instruments Other than Options, Forfeited in Period				(8,986)
Equity Other Than Options, Employee Migration	[5]			19
Awards Other than Options, Fully Vested				11,241
Equity Other Than Options, Employee Migration, Weighted Average Grant Date Fair Value				$ 37.71
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Fair Value				$ (0.6)
Equity Instruments Other than Options, Vested in Period, Aggregate Intrinsic Value				(0.5)
Equity Instruments Other than Options, Outstanding, Aggregrate Intrinsic Value				$ 1.4
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Equity Instruments Other than Options, Nonvested, Number, Beginning Balance				34,130
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted				22,911		22,665	26,141
Equity Instruments Other than Options, Vested in Period				(12,461)
Equity Instruments Other than Options, Forfeited in Period				(8,986)
Equity Other Than Options, Employee Migration	[5]			19
Equity Instruments Other than Options, Nonvested, Number, Ending Balance				35,613		34,130
Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value				$ 35.52		$ 42.67
Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value				30.91		$ 43.69	$ 41.63
Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value				45.67
Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value				$ 42.51
Fair Value of Vested Performance Units and Restricted Stock				$ 0.5		$ 0.1	$ 0
Total Compensation Cost Not yet Recognized				$ 0.8
Total Compensation Cost Not yet Recognized, Period for Recognition				1 year 4 months 20 days
Stock Compensation Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation Expense				$ 9.8		9.8	13.9
Stock Compensation Plan [Member] | Og and E [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation Expense				$ 2.2		$ 3	4.9
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward]
Equity Instruments Other than Options, Converted in Period				0		0
Performance Units Related to Earnings Per Share [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation Expense				$ 0		$ 1	4.3
Performance Units Related to Earnings Per Share [Member] | Performance Shares [Member] | Og and E [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation Expense				0		0.3	1.5
Total Shareholder Return [Member] | Performance Shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation Expense				7.5		7.9	8.7
Total Shareholder Return [Member] | Performance Shares [Member] | Og and E [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Compensation Expense				$ 1.8		$ 2.3	$ 3
[1]	These amounts represent performance units that vested at December 31, 2020 which were settled in February 2021.
[2]	Due to certain employees transferring between OG&E and OGE Energy.
[3]	For performance units, this represents the target number of performance units granted. Actual number of performance units earned, if any, is dependent upon performance and may range from zero percent to 200 percent of the target.
[4]	For performance units, this represents the target number of performance units granted. Actual number of performance units earned, if any, is dependent upon performance and may range from zero percent to 200 percent of the target.
[5]	Due to certain employees transferring between OG&E and OGE Energy.

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Regulatory Liability, Noncurrent		$ 1,231.1	$ 1,188.9
Current Federal Tax Expense (Benefit)		16.4	8.4	$ (6.4)
Current State and Local Tax Expense (Benefit)		1.7	0.5	5.1
Current Income Tax Expense (Benefit)		18.1	8.9	(1.3)
Deferred Federal Income Tax Expense (Benefit)		133.1	(105.2)	48.5
Deferred State and Local Income Tax Expense (Benefit)		(10)	(31.1)	(17.4)
Deferred Income Tax Expense (Benefit)		123.1	(136.3)	31.1
Income Tax Expense (Benefit)		$ 141.2	$ (127.4)	$ 29.8
Statutory federal tax rate		21.00%	21.00%	21.00%
Federal renewable energy credit (A)	[1]	(2.00%)	(5.00%)	(6.00%)
Effective Income Tax Rate Reconciliation, Disposition of Business, Percent	[2]	(1.10%)	0.00%	0.00%
Remeasurement of state deferred tax liabilities		(0.60%)	0.90%	(0.80%)
401(k) dividends		(0.20%)	(0.40%)	(0.40%)
State income taxes, net of federal income tax benefit		0.90%	(1.40%)	(1.20%)
Effective Income Tax Rate Reconciliation, Executive Compensation Limitation, Percent		0.10%	0.20%	0.20%
Amortization of net unfunded deferred taxes		(2.10%)	(4.40%)	(4.50%)
Other		0.00%	0.10%	(0.70%)
Effective income tax rate		16.10%	42.30%	6.40%
Accrued liabilities		$ (9.5)	$ (9.6)
Accrued vacation		(1.5)	(2.2)
Uncollectible accounts		(0.6)	(0.7)
Accelerated depreciation and other property related differences		1,677.3	1,721.2
Investment in Enable		0	302.6
Deferred Tax Liabilities, Investments		363.5	0
Regulatory assets		52.1	52.3
Income taxes recoverable from customers, net		(225.8)	(221.8)
Pension Plan		10.7	3.9
Bond redemption-unamortized costs		1.8	2
Derivative instruments		2.2	1.7
Federal tax credits		(208.4)	(236.6)
State tax credits		(221.2)	(204.4)
Postretirement medical and life insurance benefits		(19.2)	(22.4)
Net operating losses		(1)	(12)
Regulatory liabilities		(72)	(81)
Asset retirement obligations		(19.4)	(20.3)
Deferred federal investment tax credits		(3.1)	(2.7)
Other		7.4	(1.4)
Total deferred income tax liabilities, net		1,333.3	1,268.6
Unrecognized Tax Benefits		22.4	21.9	$ 20.7	$ 20.7
Current year additions		1.7	1.2	0
Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions		(1.2)	0	$ 0
Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued		0
Tax Credit Carryforward, Deferred Tax Asset		$ 208.4	$ 236.6
Stock-based compensation		0.10%	(0.30%)	(1.20%)
Effective Income Tax Rate Reconciliation, Tax Contingency, Percent	[3]	0.00%	31.60%	0.00%
Deferred Tax Asset [Member]
Unrecognized Tax Benefits		$ 18.1
State operating loss [Member]
Operating Loss Carryforwards		33.4
Deferred Tax Assets, Operating Loss Carryforwards, State and Local		1
Federal tax credits [Member]
Federal tax credits		(208.4)
Tax Credit Carryforward, Amount		208.4
Tax Credit Carryforward, Deferred Tax Asset		208.4
Oklahoma investment tax credits [Member]
State tax credits		(179.4)
Tax Credit Carryforward, Amount		227.1
Oklahoma capital investment board credits [Member]
State tax credits		(12.8)
Tax Credit Carryforward, Amount		12.8
Oklahoma zero emission tax credits [Member]
State tax credits		(28.9)
Tax Credit Carryforward, Amount		37.5
Louisiana inventory credits
State tax credits		(0.1)
Tax Credit Carryforward, Amount		0.1
Research and Development Credits [Member]
Tax Credit Carryforward, Amount		1.7	$ 1.2
Og and E [Member]
Regulatory Liability, Noncurrent		1,231.1	1,188.9
Current Federal Tax Expense (Benefit)		(9)	(3.8)	$ (7.9)
Current State and Local Tax Expense (Benefit)		9	(0.6)	4.1
Current Income Tax Expense (Benefit)		0	(4.4)	(3.8)
Deferred Federal Income Tax Expense (Benefit)		58.3	45.7	37.7
Deferred State and Local Income Tax Expense (Benefit)		(16.5)	(6.6)	(13.8)
Deferred Income Tax Expense (Benefit)		41.8	39.1	23.9
Income Tax Expense (Benefit)		$ 41.8	$ 34.7	$ 20.1
Statutory federal tax rate		21.00%	21.00%	21.00%
Federal renewable energy credit (A)	[1]	(4.40%)	(5.40%)	(7.60%)
Effective Income Tax Rate Reconciliation, Disposition of Business, Percent	[2]	0.00%	0.00%	0.00%
Remeasurement of state deferred tax liabilities		0.00%	0.00%	0.00%
401(k) dividends		0.00%	0.00%	0.00%
State income taxes, net of federal income tax benefit		(1.40%)	(1.60%)	(1.80%)
Effective Income Tax Rate Reconciliation, Executive Compensation Limitation, Percent		0.00%	0.00%	0.00%
Amortization of net unfunded deferred taxes		(4.60%)	(4.80%)	(5.60%)
Other		(0.20%)	0.10%	(0.60%)
Effective income tax rate		10.40%	9.30%	5.40%
Accrued liabilities		$ (7.3)	$ (5.2)
Accrued vacation		(1.2)	(1.6)
Uncollectible accounts		(0.6)	(0.7)
Accelerated depreciation and other property related differences		1,677.3	1,721.2
Investment in Enable		0	0
Deferred Tax Liabilities, Investments		0	0
Regulatory assets		52.1	52.3
Income taxes recoverable from customers, net		(225.8)	(221.8)
Pension Plan		32	27.4
Bond redemption-unamortized costs		1.8	2
Derivative instruments		0	0
Federal tax credits		(209.8)	(236.6)
State tax credits		(205.9)	(189)
Postretirement medical and life insurance benefits		(13)	(15.3)
Net operating losses		0	(1.4)
Regulatory liabilities		(72)	(81)
Asset retirement obligations		(19.4)	(20.3)
Deferred federal investment tax credits		(3.1)	(2.7)
Other		(4.7)	(6.5)
Total deferred income tax liabilities, net		1,000.4	1,020.8
Unrecognized Tax Benefits		18.1	17.6	$ 16.4
Tax Credit Carryforward, Deferred Tax Asset		$ 209.8	$ 236.6
Stock-based compensation		0.00%	0.00%	0.00%
Effective Income Tax Rate Reconciliation, Tax Contingency, Percent	[3]	0.00%	0.00%	0.00%
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount		$ (97.7)
Og and E [Member] | State operating loss [Member]
Operating Loss Carryforwards		0
Deferred Tax Assets, Operating Loss Carryforwards, State and Local		0
Og and E [Member] | Federal tax credits [Member]
Federal tax credits		(209.8)
Tax Credit Carryforward, Amount		209.8
Tax Credit Carryforward, Deferred Tax Asset		209.8
Og and E [Member] | Oklahoma investment tax credits [Member]
State tax credits		(164.2)
Tax Credit Carryforward, Amount		207.8
Og and E [Member] | Oklahoma capital investment board credits [Member]
State tax credits		(12.8)
Tax Credit Carryforward, Amount		12.8
Og and E [Member] | Oklahoma zero emission tax credits [Member]
State tax credits		(28.9)
Tax Credit Carryforward, Amount		37.5
Og and E [Member] | Louisiana inventory credits
State tax credits		0
Tax Credit Carryforward, Amount		0
OGE Energy [Member]
Effective Income Tax Rate Reconciliation, Change in Enacted Tax Rate, Amount		$ 6.6
[1]	Represents credits primarily associated with the production from OG&E's wind farms.
[2]	In connection with the Enable and Energy Transfer merger, the state income tax rates are expected to decrease, as Energy Transfer operates in significantly more states with generally lower tax rates than the historic Enable operating area.
[3]	As further discussed in Note 5, OGE Energy recorded a $780.0 million impairment on its investment in Enable in March 2020, which resulted in a tax benefit being recorded that caused a significant variance to the effective tax rate. This variance has been presented in the table as a single line item in order to facilitate comparability of other components of the effective tax rate.

Common Equity Automatic Dividen

Common Equity Automatic Dividend Reinvestment and Stock Purchase Plan (Details) - Automatic Dividend Reinvestment and Stock Purchase Plan [Member]	12 Months Ended
	Dec. 31, 2021shares
Stock Issued During Period, Shares, Dividend Reinvestment Plan and Stock Purchase Plan	0
Shares Held in Reserve Related to Dividend Reinvestment Plan and Stock Purchase Plan	4,774,442

Common Equity Earnings Per Shar

Common Equity Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount	0	300	0
Net income attributable to OGE Energy	$ 737.3	$ (173.7)	$ 433.6
Basic Average Common Shares Outstanding	200,100	200,100	200,100
Contingently Issuable Shares (Performance and Restricted Stock Units)	200	0	600
Diluted Average Common Shares Outstanding	200,300	200,100	200,700
Earnings Per Share, Basic and Diluted [Abstract]
Basic earnings per average common share attributable to OGE Energy common shareholders	$ 3.68	$ (0.87)	$ 2.17
Diluted earnings per average common share attributable to OGE Energy common shareholders	$ 3.68	$ (0.87)	$ 2.16
Og and E [Member]
Stock Issued During Period, Shares, New Issues	0	0	0
Retained Earnings [Member]
Net income attributable to OGE Energy	$ 737.3	$ (173.7)	$ 433.6

Common Equity Dividends Restric

Common Equity Dividends Restriction (Details) shares in Millions, $ in Millions	Dec. 31, 2021USD ($)shares
Preferred Stock, Shares Outstanding | shares	0
OGE Energy [Member]
Ratio of Consolidated Debt to Consolidated Capitalization	65.00%
Retained Earnings, Restricted	$ 1,600
Retained Earnings, Unrestricted	$ 1,400
Og and E [Member]
Ratio of Consolidated Debt to Consolidated Capitalization	65.00%
Retained Earnings, Restricted	$ 580.9
Retained Earnings, Unrestricted	$ 2,500

Long-Term Debt (Details)

Long-Term Debt (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Total long-term debt	$ 4,496.4	$ 3,494.4
Percent of Principal Amount Subject to Optional Tender	100.00%
Debt Instrument, Face Amount	$ 1,000
Garfield Industrial Authority, January 1, 2025 [Member]
Debt Instrument [Line Items]
Date Due	Jan. 1, 2025
Muskogee Industrial Authority, Janaury 1, 2025 [Member]
Debt Instrument [Line Items]
Date Due	Jan. 1, 2025
Muskogee Industrial Authority, June 1, 2027 [Member]
Debt Instrument [Line Items]
Date Due	Jun. 1, 2027
Redeemable during the next 12 months
Debt Instrument [Line Items]
Total long-term debt	$ 135.4
OG&E [Member]
Debt Instrument [Line Items]
Total long-term debt	3,996.5	3,494.4
Long-term Debt, Maturities, Repayments of Principal in Year Two	500
Long-term Debt, Maturities, Repayments of Principal in Year Four	79.4
OG&E [Member] | Redeemable during the next 12 months | Garfield Industrial Authority, January 1, 2025 [Member]
Debt Instrument [Line Items]
Long term debt, gross	47	47
OG&E [Member] | Redeemable during the next 12 months | Muskogee Industrial Authority, Janaury 1, 2025 [Member]
Debt Instrument [Line Items]
Long term debt, gross	32.4	32.4
OG&E [Member] | Redeemable during the next 12 months | Muskogee Industrial Authority, June 1, 2027 [Member]
Debt Instrument [Line Items]
Long term debt, gross	56	56
OGE Energy [Member]
Debt Instrument [Line Items]
Long-term Debt, Maturities, Repayments of Principal in Year Two	1,000
Long-term Debt, Maturities, Repayments of Principal in Year Four	79.4
Senior Notes [Member] | OG&E [Member] | Series Due April 1, 2030
Debt Instrument [Line Items]
Long term debt, gross	$ 300	300
Debt Instrument, Interest Rate, Stated Percentage	3.25%
Date Due	Apr. 1, 2030
Senior Notes [Member] | OG&E [Member] | Series Due May 26, 2023
Debt Instrument [Line Items]
Long term debt, gross	$ 500	0
Debt Instrument, Interest Rate, Stated Percentage	0.553%
Date Due	May 26, 2023
Senior Notes [Member] | OGE Energy [Member] | Series Due May 26, 2023
Debt Instrument [Line Items]
Long term debt, gross	$ 500	$ 0
Debt Instrument, Interest Rate, Stated Percentage	0.703%
Date Due	May 26, 2023
Minimum [Member] | Redeemable during the next 12 months | Garfield Industrial Authority, January 1, 2025 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	0.11%
Minimum [Member] | Redeemable during the next 12 months | Muskogee Industrial Authority, Janaury 1, 2025 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	0.11%
Minimum [Member] | Redeemable during the next 12 months | Muskogee Industrial Authority, June 1, 2027 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	0.11%
Maximum [Member] | Redeemable during the next 12 months | Garfield Industrial Authority, January 1, 2025 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	0.27%
Maximum [Member] | Redeemable during the next 12 months | Muskogee Industrial Authority, Janaury 1, 2025 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	0.33%
Maximum [Member] | Redeemable during the next 12 months | Muskogee Industrial Authority, June 1, 2027 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	0.27%

Short-Term Debt and Credit Fa_3

Short-Term Debt and Credit Facilities (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020
Line of Credit Facility [Line Items]
Short-term debt		$ 486.9	$ 95
Line of Credit Facility [Abstract]
Aggregate Commitment		1,100
Amount Outstanding	[1]	$ 487.3
Weighted Average Interest Rate		0.36%
Acceleration of Indebtedness of Credit Facility		$ 100
Nonpayment of Uninsured Judgments		100
Outstanding Intercompany Borrowings		60
Proceeds from (Repayments of) Related Party Debt		470
Debt Instrument, Face Amount		1,000
OGE Energy [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Current Borrowing Capacity	[2]	550
Line of Credit Facility [Abstract]
Amount Outstanding	[1],[2]	$ 486.9
Weighted Average Interest Rate	[2],[3]	0.36%
Maturity	[2]	Dec. 17, 2026
Ratio of Consolidated Debt to Consolidated Capitalization		65.00%
OG&E [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Current Borrowing Capacity	[4],[5]	$ 550
Line of Credit Facility [Abstract]
Letters of Credit Outstanding, Amount	[1],[4],[5]	$ 0.4
Weighted Average Interest Rate	[3],[4],[5]	1.15%
Maturity	[4],[5]	Dec. 17, 2026
Intercompany Borrowing Agreement - Maximum Borrowing Capacity		$ 350
Period For Which Regulatory Approval Has Been Given to Acquire Short Term Debt		2 years
Short Term Borrowing Capacity That Has Regulatory Approval		$ 800
Ratio of Consolidated Debt to Consolidated Capitalization		65.00%
Proceeds from Contributed Capital		$ 530
Advances from parent		101.3	0
Advances to parent		$ 0	$ 272
[1]	Includes direct borrowings under the revolving credit agreements, commercial paper borrowings and letters of credit at December 31, 2021.
[2]	This bank facility is available to back up OGE Energy's commercial paper borrowings and to provide revolving credit borrowings. This bank facility can also be used as a letter of credit facility.
[3]	Represents the weighted-average interest rate for the outstanding borrowings under the revolving credit agreements, commercial paper borrowings and letters of credit
[4]	OG&E has an intercompany borrowing agreement with OGE Energy whereby OG&E has access to up to $350.0 million of OGE Energy's revolving credit amount. This agreement has a termination date of December 17, 2026. At December 31, 2021, there were $60.0 million in intercompany borrowings under this agreement.
[5]	This bank facility is available to back up OG&E's commercial paper borrowings and to provide revolving credit borrowings. This bank facility can also be used as a letter of credit facility.

Retirement Plans and Postreti_3

Retirement Plans and Postretirement Benefit Plans (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2021		Dec. 31, 2020		Dec. 31, 2019
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Contribution Plan, Employer Matching Contribution, Percent of Match		200.00%
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay		5.00%
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Employer contributions		$ 40		$ 20
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Ultimate Health Care Cost Trend Rate		4.50%
Expected Future Benefit Payments, Next Twelve Months		$ 95.3
Expected Future Benefit Payments, Year Two		37
Expected Future Benefit Payments, Year Three		38.4
Expected Future Benefit Payments, Year Four		36.7
Expected Future Benefit Payments, Year Five		35.2
Expected Future Benefit Payments, Five Fiscal Years Thereafter		167.4
Defined Contribution Plan, Cost		15.4		18.2		$ 14.4
Postemployment Benefits Liability		2		2.2
Og and E [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Employer contributions		30		10
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Expected Future Benefit Payments, Next Twelve Months		38.8
Expected Future Benefit Payments, Year Two		30.7
Expected Future Benefit Payments, Year Three		30.6
Expected Future Benefit Payments, Year Four		28.7
Expected Future Benefit Payments, Year Five		28.3
Expected Future Benefit Payments, Five Fiscal Years Thereafter		126.6
Defined Contribution Plan, Cost		12		14.3		11
Postemployment Benefits Liability		1.5		1.8
Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Benefits Paid		(14.1)		(14.2)
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment		0		0
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation, Beginning		654.6		616.1
Service cost		11.2		13.2		12.9
Interest cost		13.3		17		20.7
Plan curtailments		0		0
Defined Benefit Plan, Benefit Obligation, Special and Contractual Termination Benefits		0		7.6
Plan settlements		(158.6)		(42.8)
Actuarial (gains) losses		(3.5)		57.7
Benefit Obligation, Ending		502.9		654.6		616.1
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		570.3		530.3
Actual return on plans' assets		48.4		77
Employer contributions		40		20
Plan settlements		(158.6)		(42.8)
Fair Value of Plan Assets, Ending		486		570.3		530.3
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost		11.2		13.2		12.9
Interest cost		13.3		17		20.7
Expected return on plan assets		(34.1)		(37.6)		(36.1)
Defined Benefit Plan, Amortization of Gain (Loss)		(9.4)		(17.1)		(17.3)
Amortization of unrecognized prior service cost	[1]	0		0		0
Curtailment		0		0		0
Defined Benefit Plan, Cost of Providing Special and Contractual Termination Benefits		0		7.6		0
Settlement cost		41.3		14.1		27.6
Net periodic benefit cost		41.1		31.4		42.4
Amount paid by unconsolidated affiliates	[2]	(0.2)		2		2.9
Net Periodic Benefit Cost, Net of Unconsolidated Affiliates		41.3		29.4		39.5
Plan settlements		(158.6)		(42.8)
Capitalized Portion of Net Periodic Benefit Cost		$ 3.4		$ 3.8		$ 3.6
Assumptions Used Calculating Benefit Obligation, Discount Rate		2.75%		2.30%		3.15%
Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Return on Assets		7.00%		7.50%		7.50%
Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase		4.20%		4.20%		4.20%
Fair Value of Plan Assets, Beginning		$ 570.3		$ 530.3
Defined Benefit Plan, Benefit Obligation, Benefits Paid		(14.1)		(14.2)
Accumulated Benefit Obligation		(475.2)		(610.8)
Pension Plans, Defined Benefit [Member] | Og and E [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Benefits Paid		(11.9)		(12.3)
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation, Beginning		484.1		462
Service cost		7.7		9.2		$ 9
Interest cost		9.7		12.6		15.6
Plan curtailments		0		0
Defined Benefit Plan, Benefit Obligation, Special and Contractual Termination Benefits		0		5.1
Plan settlements		(120.4)		(33.5)
Actuarial (gains) losses		(6)		41
Benefit Obligation, Ending		363.2		484.1		462
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		420.3		399.1
Actual return on plans' assets		35		57
Employer contributions		30		10
Plan settlements		(120.4)		(33.5)
Fair Value of Plan Assets, Ending		353		420.3		399.1
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost		7.7		9.2		9
Interest cost		9.7		12.6		15.6
Expected return on plan assets		(24.7)		(27.9)		(27.6)
Defined Benefit Plan, Amortization of Gain (Loss)		(7)		(12.1)		(12.9)
Amortization of unrecognized prior service cost	[1]	0		0		0
Curtailment		0		0		0
Defined Benefit Plan, Cost of Providing Special and Contractual Termination Benefits		0		5.1		0
Settlement cost		33.1		11.4		16.4
Net periodic benefit cost		32.8		22.5		26.3
Amount Attributable to Parent	[2]	6.5		5.9		4.5
Net Periodic Benefit Cost, Net of Unconsolidated Affiliates		39.3		28.4		30.8
Plan settlements		(120.4)		(33.5)
Capitalized Portion of Net Periodic Benefit Cost		2.9		3.1		3
Fair Value of Plan Assets, Beginning		420.3		399.1
Defined Benefit Plan, Benefit Obligation, Benefits Paid		(11.9)		(12.3)
Accumulated Benefit Obligation		(341)		(454.7)
Pension Plans, Defined Benefit [Member] | OKLAHOMA
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Settlement cost	[3]	37.9		21.6		17.9
Additional Pension Expense to Meet State Requirements	[3]	23		13.8		16.1
Pension Plans, Defined Benefit [Member] | ARKANSAS
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Settlement cost	[3]	3.5		2		1.7
Pension Plans, Defined Benefit [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		0
Fair Value of Plan Assets, Ending		0		0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		0
Restoration of Retirement Income Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Benefits Paid		0		0
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment		1.4		0
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation, Beginning		7.8		10.3
Service cost		0.8		0.8		0.5
Interest cost		0.1		0.2		0.4
Plan curtailments		(0.1)		0.2
Defined Benefit Plan, Benefit Obligation, Special and Contractual Termination Benefits		0		0
Plan settlements		(4.6)		(5.3)
Actuarial (gains) losses		0.5		1.6
Benefit Obligation, Ending		5.9		7.8		10.3
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		0		0
Actual return on plans' assets		0		0
Employer contributions		4.6		5.3
Plan settlements		(4.6)		(5.3)
Fair Value of Plan Assets, Ending		0		0		0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost		0.8		0.8		0.5
Interest cost		0.1		0.2		0.4
Expected return on plan assets		0		0		0
Defined Benefit Plan, Amortization of Gain (Loss)		(0.2)		(0.5)		(0.5)
Amortization of unrecognized prior service cost	[1]	0.1		0		0
Curtailment		0		(0.2)		0
Defined Benefit Plan, Cost of Providing Special and Contractual Termination Benefits		0		0		0
Settlement cost		2.1		2.7		0.5
Net periodic benefit cost		3.3		4.4		1.9
Amount paid by unconsolidated affiliates	[2]	0.1		0.1		0.1
Net Periodic Benefit Cost, Net of Unconsolidated Affiliates		3.2		4.3		1.8
Plan settlements		(4.6)		(5.3)
Fair Value of Plan Assets, Beginning		0		0
Defined Benefit Plan, Benefit Obligation, Benefits Paid		0		0
Accumulated Benefit Obligation		(5.4)		(6.9)
Restoration of Retirement Income Plan [Member] | Og and E [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Benefits Paid		0		0
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation, Beginning		3		6.1
Service cost		0		0.1		0.2
Interest cost		0		0.1		0.2
Plan curtailments		0		0
Defined Benefit Plan, Benefit Obligation, Special and Contractual Termination Benefits		0		0
Plan settlements		(2.9)		(4.5)
Actuarial (gains) losses		0.4		1.2
Benefit Obligation, Ending		0.5		3		6.1
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		0		0
Actual return on plans' assets		0		0
Employer contributions		2.9		4.5
Plan settlements		(2.9)		(4.5)
Fair Value of Plan Assets, Ending		0		0		0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost		0		0.1		0.2
Interest cost		0		0.1		0.2
Expected return on plan assets		0		0		0
Defined Benefit Plan, Amortization of Gain (Loss)		(0.1)		(0.4)		(0.3)
Amortization of unrecognized prior service cost	[1]	0		0		0
Curtailment		0		0		0
Defined Benefit Plan, Cost of Providing Special and Contractual Termination Benefits		0		0		0
Settlement cost		1.6		2.4		0.5
Net periodic benefit cost		1.7		3		1.2
Amount Attributable to Parent	[2]	1.5		1.3		0.5
Net Periodic Benefit Cost, Net of Unconsolidated Affiliates		3.2		4.3		1.7
Plan settlements		(2.9)		(4.5)
Fair Value of Plan Assets, Beginning		0		0
Defined Benefit Plan, Benefit Obligation, Benefits Paid		0		0
Accumulated Benefit Obligation		(0.4)		(2.9)
Other Postretirement Benefits Plan [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Benefits Paid		(12.5)		(11)
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment		0		0
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation, Beginning		144.5		136.5
Service cost		0.2		0.2		0.2
Interest cost		3.4		4.2		5.6
Plan curtailments		1.9		4
Defined Benefit Plan, Plan Assets, Contributions by Plan Participant		(3.5)		(3.3)
Actuarial (gains) losses		(3.7)		7.3
Benefit Obligation, Ending		137.3		144.5		136.5
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		47.6		47
Actual return on plans' assets		(0.5)		1.2
Employer contributions		6.2		7.1
Fair Value of Plan Assets, Ending		44.3		47.6		47
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost		0.2		0.2		0.2
Interest cost		3.4		4.2		5.6
Expected return on plan assets		(1.8)		(1.8)		(1.9)
Defined Benefit Plan, Amortization of Gain (Loss)		(2.8)		(2)		(2)
Amortization of unrecognized prior service cost	[1]	(6.9)		(8.4)		(8.4)
Curtailment		0		(1.5)		0
Net periodic benefit cost		(2.3)		(2.3)		(2.5)
Amount paid by unconsolidated affiliates	[4]	(0.5)		(0.7)		(0.6)
Net Periodic Benefit Cost, Net of Unconsolidated Affiliates		(1.8)		(1.6)		(1.9)
Capitalized Portion of Net Periodic Benefit Cost		$ 0.2		$ 0.2		$ 0.2
Assumptions Used Calculating Benefit Obligation, Discount Rate		2.80%		2.45%		3.25%
Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Return on Assets		4.00%		4.00%		4.00%
Health Care Cost Trend Rate Assumed for Next Fiscal Year		6.50%
Fair Value of Plan Assets, Beginning		$ 47.6		$ 47
Defined Benefit Plan, Benefit Obligation, Contributions by Plan Participant		3.5		3.3
Defined Benefit Plan, Benefit Obligation, Benefits Paid		(12.5)		(11)
Accumulated Benefit Obligation		(93)		(96.9)
Other Postretirement Benefits Plan [Member] | Og and E [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Defined Benefit Plan, Plan Assets, Benefits Paid		(9.9)		(8.6)
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation, Beginning		109.5		104.7
Service cost		0.1		0.2		$ 0.2
Interest cost		2.6		3.2		4.3
Plan curtailments		0		3.1
Defined Benefit Plan, Plan Assets, Contributions by Plan Participant		(2.6)		(2.4)
Actuarial (gains) losses		(2.5)		4.5
Benefit Obligation, Ending		102.4		109.5		104.7
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		42.7		41.9
Actual return on plans' assets		(0.5)		1.1
Employer contributions		5		5.9
Fair Value of Plan Assets, Ending		39.9		42.7		41.9
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost		0.1		0.2		0.2
Interest cost		2.6		3.2		4.3
Expected return on plan assets		(1.7)		(1.7)		(1.7)
Defined Benefit Plan, Amortization of Gain (Loss)		(2.7)		(2.1)		(2.1)
Amortization of unrecognized prior service cost	[1]	(5)		(6.1)		(6.1)
Curtailment		0		(1.3)		0
Net periodic benefit cost		(1.3)		(1)		(1.2)
Amount Attributable to Parent	[4]	(0.5)		(0.5)		(0.6)
Net Periodic Benefit Cost, Net of Unconsolidated Affiliates		(1.8)		(1.5)		(1.8)
Capitalized Portion of Net Periodic Benefit Cost		0.1		0.1		0.1
Fair Value of Plan Assets, Beginning		42.7		41.9
Defined Benefit Plan, Benefit Obligation, Contributions by Plan Participant		2.6		2.4
Defined Benefit Plan, Benefit Obligation, Benefits Paid		(9.9)		(8.6)
Accumulated Benefit Obligation		(62.5)		(66.8)
Other Postretirement Benefits Plan [Member] | OKLAHOMA
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Settlement cost	[5]	0		(1.4)		0
Additional Pension Expense to Meet State Requirements	[5]	0.4		0.2		1
Other Postretirement Benefits Plan [Member] | ARKANSAS
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Settlement cost	[5]	0		(0.1)		$ 0
Other Postretirement Benefits Plan [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		14.2
Fair Value of Plan Assets, Ending		16.2		14.2
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		14.2
Other Postretirement Benefits Plan [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		0
Fair Value of Plan Assets, Ending		0		0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		0
Other Postretirement Benefits Plan [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		33.4
Fair Value of Plan Assets, Ending		28.1		33.4
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		33.4
Other Postretirement Benefits Plan [Member] | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		47.6
Fair Value of Plan Assets, Ending		44.3		47.6
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		47.6
Other Postretirement Benefits Plan [Member] | Fair Value, Inputs, Level 1, 2 and 3 [Member] | Og and E [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		42.7
Fair Value of Plan Assets, Ending		39.9		42.7
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		$ 42.7
Less Than 90% [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Projected Benefit Obligation Funded Status Thresholds Fixed Income		50.00%
Projected Benefit Obligation Funded Status Thresholds Equity		50.00%
Projected Benefit Obligation Funded Status Thresholds		100.00%
95% [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Projected Benefit Obligation Funded Status Thresholds Fixed Income		58.00%
Projected Benefit Obligation Funded Status Thresholds Equity		42.00%
Projected Benefit Obligation Funded Status Thresholds		100.00%
100% [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Projected Benefit Obligation Funded Status Thresholds Fixed Income		65.00%
Projected Benefit Obligation Funded Status Thresholds Equity		35.00%
Projected Benefit Obligation Funded Status Thresholds		100.00%
105% [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Projected Benefit Obligation Funded Status Thresholds Fixed Income		73.00%
Projected Benefit Obligation Funded Status Thresholds Equity		27.00%
Projected Benefit Obligation Funded Status Thresholds		100.00%
110% [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Projected Benefit Obligation Funded Status Thresholds Fixed Income		80.00%
Projected Benefit Obligation Funded Status Thresholds Equity		20.00%
Projected Benefit Obligation Funded Status Thresholds		100.00%
115% [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Projected Benefit Obligation Funded Status Thresholds Fixed Income		85.00%
Projected Benefit Obligation Funded Status Thresholds Equity		15.00%
Projected Benefit Obligation Funded Status Thresholds		100.00%
120% [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Projected Benefit Obligation Funded Status Thresholds Fixed Income		90.00%
Projected Benefit Obligation Funded Status Thresholds Equity		10.00%
Projected Benefit Obligation Funded Status Thresholds		100.00%
Domestic All-Cap/Large Cap Equity [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Target Plan Asset Allocations		40.00%
Domestic Mid-Cap Equity [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Target Plan Asset Allocations		15.00%
Domestic Small-Cap Equity [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Target Plan Asset Allocations		25.00%
International Equity [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Target Plan Asset Allocations		20.00%
Minimum [Member] | Domestic All-Cap/Large Cap Equity [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Target Plan Asset Allocations		35.00%
Minimum [Member] | Domestic Mid-Cap Equity [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Target Plan Asset Allocations		5.00%
Minimum [Member] | Domestic Small-Cap Equity [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Target Plan Asset Allocations		5.00%
Minimum [Member] | International Equity [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Target Plan Asset Allocations		10.00%
Maximum [Member] | Domestic All-Cap/Large Cap Equity [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Target Plan Asset Allocations		60.00%
Maximum [Member] | Domestic Mid-Cap Equity [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Target Plan Asset Allocations		25.00%
Maximum [Member] | Domestic Small-Cap Equity [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Target Plan Asset Allocations		30.00%
Maximum [Member] | International Equity [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Target Plan Asset Allocations		30.00%
Group Retiree Medical Insurance Contract [Member] | Other Postretirement Benefits Plan [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		$ 33.4
Fair Value of Plan Assets, Ending		28.1		33.4
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		33.4
Group Retiree Medical Insurance Contract [Member] | Other Postretirement Benefits Plan [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		0
Fair Value of Plan Assets, Ending		0		0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		0
Group Retiree Medical Insurance Contract [Member] | Other Postretirement Benefits Plan [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		33.4
Fair Value of Plan Assets, Ending		28.1		33.4
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		33.4
U.S. common stocks [Member] | Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Alternative Investment		0	[6]	0	[7]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		252.3
Fair Value of Plan Assets, Ending		86.1		252.3
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		252.3
U.S. common stocks [Member] | Pension Plans, Defined Benefit [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		252.3
Fair Value of Plan Assets, Ending		86.1		252.3
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		252.3
U.S. common stocks [Member] | Pension Plans, Defined Benefit [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		0
Fair Value of Plan Assets, Ending		0		0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		0
U.S. treasury notes and bonds [Member] | Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Alternative Investment		0	[6],[8]	0	[7],[9]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning	[9]	134.3
Fair Value of Plan Assets, Ending		135.2	[8]	134.3	[9]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning	[9]	134.3
U.S. treasury notes and bonds [Member] | Pension Plans, Defined Benefit [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning	[9]	134.3
Fair Value of Plan Assets, Ending		135.2	[8]	134.3	[9]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning	[9]	134.3
U.S. treasury notes and bonds [Member] | Pension Plans, Defined Benefit [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning	[9]	0
Fair Value of Plan Assets, Ending		0	[8]	0	[9]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning	[9]	0
Mortgage-backed securities | Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Alternative Investment		0	[6]	0	[7]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		29.3
Fair Value of Plan Assets, Ending		24.6		29.3
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		29.3
Mortgage-backed securities | Pension Plans, Defined Benefit [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		0
Fair Value of Plan Assets, Ending		0		0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		0
Mortgage-backed securities | Pension Plans, Defined Benefit [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		29.3
Fair Value of Plan Assets, Ending		24.6		29.3
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		29.3
Corporate fixed income and other securities [Member] | Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Alternative Investment		0	[6]	0	[7]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		116.6
Fair Value of Plan Assets, Ending		107		116.6
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		116.6
Corporate fixed income and other securities [Member] | Pension Plans, Defined Benefit [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		0
Fair Value of Plan Assets, Ending		0		0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		0
Corporate fixed income and other securities [Member] | Pension Plans, Defined Benefit [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		116.6
Fair Value of Plan Assets, Ending		107		116.6
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		116.6
Commingled fund [Member] | Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Alternative Investment		23.6	[6],[10]	25.4	[7],[11]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning	[11]	25.4
Fair Value of Plan Assets, Ending		23.6	[10]	25.4	[11]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning	[11]	25.4
Commingled fund [Member] | Pension Plans, Defined Benefit [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning	[11]	0
Fair Value of Plan Assets, Ending		0	[10]	0	[11]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning	[11]	0
Commingled fund [Member] | Pension Plans, Defined Benefit [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning	[11]	0
Fair Value of Plan Assets, Ending		0	[10]	0	[11]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning	[11]	0
Foreign government bonds [Member] | Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Alternative Investment		0	[6]	0	[7]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		4.6
Fair Value of Plan Assets, Ending		0.9		4.6
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		4.6
Foreign government bonds [Member] | Pension Plans, Defined Benefit [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		0
Fair Value of Plan Assets, Ending		0		0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		0
Foreign government bonds [Member] | Pension Plans, Defined Benefit [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		4.6
Fair Value of Plan Assets, Ending		0.9		4.6
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		4.6
Municipal bonds [Member] | Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Alternative Investment		0	[6]	0	[7]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		1.8
Fair Value of Plan Assets, Ending		1.4		1.8
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		1.8
Municipal bonds [Member] | Pension Plans, Defined Benefit [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		0
Fair Value of Plan Assets, Ending		0		0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		0
Municipal bonds [Member] | Pension Plans, Defined Benefit [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		1.8
Fair Value of Plan Assets, Ending		1.4		1.8
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		1.8
Money market funds [Member] | Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Alternative Investment		5.5	[6]	8.8	[7]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		8.8
Fair Value of Plan Assets, Ending		5.5		8.8
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		8.8
Money market funds [Member] | Pension Plans, Defined Benefit [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		0
Fair Value of Plan Assets, Ending		0		0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		0
Money market funds [Member] | Pension Plans, Defined Benefit [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		0
Fair Value of Plan Assets, Ending		0		0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		0
Mutual fund [Member] | Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Alternative Investment		0	[6]	0	[7]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		9.2
Fair Value of Plan Assets, Ending		99.8		9.2
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		9.2
Mutual fund [Member] | Pension Plans, Defined Benefit [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		9.2
Fair Value of Plan Assets, Ending		99.8		9.2
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		9.2
Mutual fund [Member] | Pension Plans, Defined Benefit [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		0
Fair Value of Plan Assets, Ending		0		0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		0
Cash collateral [Member] | Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Alternative Investment		0	[6]	0	[7]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		0.7
Fair Value of Plan Assets, Ending		0.6		0.7
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		0.7
Cash collateral [Member] | Pension Plans, Defined Benefit [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		0.7
Fair Value of Plan Assets, Ending		0.6		0.7
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		0.7
Cash collateral [Member] | Pension Plans, Defined Benefit [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		0
Fair Value of Plan Assets, Ending		0		0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		0
Receivable (foreign currency) [Member] | Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Alternative Investment		0	[6]	0	[7]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		0.1
Fair Value of Plan Assets, Ending		0.1		0.1
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		0.1
Receivable (foreign currency) [Member] | Pension Plans, Defined Benefit [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		0
Fair Value of Plan Assets, Ending		0		0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		0
Receivable (foreign currency) [Member] | Pension Plans, Defined Benefit [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		0.1
Fair Value of Plan Assets, Ending		0.1		0.1
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		0.1
Preferred stocks (foreign) [Member] | Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Alternative Investment		0	[6]	0	[7]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		0.6
Fair Value of Plan Assets, Ending		1.1		0.6
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		0.6
Preferred stocks (foreign) [Member] | Pension Plans, Defined Benefit [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		0.6
Fair Value of Plan Assets, Ending		1.1		0.6
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		0.6
Preferred stocks (foreign) [Member] | Pension Plans, Defined Benefit [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		0
Fair Value of Plan Assets, Ending		0		0
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		0
Total Plan investments [Member] | Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Alternative Investment		29.1	[6]	34.2	[7]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		583.7
Fair Value of Plan Assets, Ending		485.9		583.7
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		583.7
Total Plan investments [Member] | Pension Plans, Defined Benefit [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		397.1
Fair Value of Plan Assets, Ending		322.8		397.1
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		397.1
Total Plan investments [Member] | Pension Plans, Defined Benefit [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		152.4
Fair Value of Plan Assets, Ending		134		152.4
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		152.4
Receivable from broker for securities sold [Member] | Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		0.2
Fair Value of Plan Assets, Ending				0.2
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		0.2
Interest and dividends receivable [Member] | Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		2.2
Fair Value of Plan Assets, Ending		2.1		2.2
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		2.2
Payable to broker for securities purchased [Member] | Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		(15.8)
Fair Value of Plan Assets, Ending		(2)		(15.8)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		(15.8)
Total Plan assets [Member] | Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		570.3
Fair Value of Plan Assets, Ending		486		570.3
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		570.3
Total Plan assets [Member] | Pension Plans, Defined Benefit [Member] | Og and E [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		420.3
Fair Value of Plan Assets, Ending		353		420.3
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		420.3
Plan Assets Attributable to Affiliates | Pension Plans, Defined Benefit [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		(150)
Fair Value of Plan Assets, Ending		(133)		$ (150)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Fair Value of Plan Assets, Beginning		$ (150)
[1]	Unamortized prior service cost is amortized on a straight-line basis over the average remaining service period to the first eligibility age of participants who are expected to receive a benefit and are active at the date of the plan amendment.
[2]	"Amount paid by unconsolidated affiliates" is only applicable to OGE Energy. "Amount allocated from OGE Energy" is only applicable to OG&E.
[3]	Included in the pension regulatory asset or liability in each jurisdiction, as indicated in the regulatory assets and liabilities table in Note 1.
[4]	"Amount paid by unconsolidated affiliates" is only applicable to OGE Energy. "Amount allocated from OGE Energy" is only applicable to OG&E.
[5]	Included in the pension regulatory asset or liability in each jurisdiction, as indicated in the regulatory assets and liabilities table in Note 1.
[6]	GAAP allows the measurement of certain investments that do not have a readily determinable fair value at the net asset value. These investments do not consider the observability of inputs; therefore, they are not included within the fair value hierarchy.
[7]	GAAP allows the measurement of certain investments that do not have a readily determinable fair value at the net asset value. These investments do not consider the observability of inputs; therefore, they are not included within the fair value hierarchy.
[8]	This category represents U.S. Treasury notes and bonds with a Moody's Investors Service rating of Aaa and Government Agency Bonds with a Moody's Investors Service rating of A1 or higher.
[9]	This category represents U.S. Treasury notes and bonds with a Moody's Investors Service rating of Aaa and Government Agency Bonds with a Moody's Investors Service rating of A1 or higher.
[10]	This category represents units of participation in a commingled fund that primarily invested in stocks of international companies and emerging markets.
[11]	This category represents units of participation in a commingled fund that primarily invested in stocks of international companies and emerging markets.

Retirement Plans and Postreti_4

Retirement Plans and Postretirement Benefit Plans Postretirement Benefit Plans (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2021		Dec. 31, 2020		Dec. 31, 2019
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Employer contributions		$ 40		$ 20
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Level 3 Asset Value, Beginning of Period		33.4
Interest income		0.7
Dividend income		0.2
Unrealized gains		(1.1)
Realized losses		(0.1)
Administrative expenses and charges		(0.1)
Claims paid		(4.9)
Level 3 Asset Value, End of Period		28.1		33.4
Postretirement Plan, Expected Future Benefit Payments, Next Twelve Months		12.5
Postretirement Plan, Expected Future Benefit Payments, Year Two		12.2
Postretirement Plan, Expected Future Benefit Payments, Year Three		10.6
Postretirement Plan, Expected Future Benefit Payments in Year Four		10.1
Postretirement Plan, Expected Future Benefit Payments, Year Five		9.7
Postretirement Plan, Expected Future Benefit Payments, Five Fiscal Years Thereafter		40.3
Postemployment Benefits Liability		$ 2		$ 2.2
Ultimate Health Care Cost Trend Rate		4.50%
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Weighted-Average Interest Crediting Rate		3.50%		3.50%		4.00%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Weighted-Average Interest Crediting Rate		3.50%		4.00%		4.00%
Defined Contribution Plan, Cost		$ 15.4		$ 18.2		$ 14.4
Defined Contribution Plan, Employer Matching Contribution, Percent of Employees' Gross Pay		5.00%
Defined Contribution Plan, Employer Matching Contribution, Percent of Match		200.00%
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Asset Value		$ 28.1		33.4
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Claims Paid		4.9
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Administrative Expenses and Charges		0.1
Unrealized gains		(1.1)
Interest income		0.7
Dividend income		0.2
Og and E [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Employer contributions		30		10
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Postretirement Plan, Expected Future Benefit Payments, Next Twelve Months		9.6
Postretirement Plan, Expected Future Benefit Payments, Year Two		9.3
Postretirement Plan, Expected Future Benefit Payments, Year Three		8
Postretirement Plan, Expected Future Benefit Payments in Year Four		7.6
Postretirement Plan, Expected Future Benefit Payments, Year Five		7.2
Postretirement Plan, Expected Future Benefit Payments, Five Fiscal Years Thereafter		30.2
Postemployment Benefits Liability		1.5		1.8
Defined Contribution Plan, Cost		12		14.3		11
Pension Plan [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation, Beginning		654.6		616.1
Service cost		11.2		13.2		12.9
Interest cost		13.3		17		20.7
Plan settlements		(158.6)		(42.8)
Actuarial (gains) losses		(3.5)		57.7
Benefit Obligation, Ending		502.9		654.6		616.1
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		570.3		530.3
Actual return on plans' assets		48.4		77
Employer contributions		40		20
Plan settlements		(158.6)		(42.8)
Fair Value of Plan Assets, Ending		486		570.3		530.3
Funded Status of Plan		(16.9)		(84.3)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost		11.2		13.2		12.9
Interest cost		13.3		17		20.7
Expected return on plan assets		(34.1)		(37.6)		(36.1)
Amortization of unrecognized prior service cost	[1]	0		0		0
Curtailment		0		0		0
Settlement cost		41.3		14.1		27.6
Net periodic benefit cost		41.1		31.4		42.4
Amount paid by unconsolidated affiliates	[2]	(0.2)		2		2.9
Net Periodic Benefit Cost, Net of Unconsolidated Affiliates		41.3		29.4		39.5
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Capitalized Portion of Net Periodic Benefit Cost		$ 3.4		$ 3.8		$ 3.6
Assumptions Used Calculating Benefit Obligation, Discount Rate		2.75%		2.30%		3.15%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate		2.63%		2.88%		3.63%
Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Return on Assets		7.00%		7.50%		7.50%
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Rate of Compensation Increase		4.20%		4.20%		4.20%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Rate of Compensation Increase		4.20%		4.20%		4.20%
Defined Benefit Plan, Benefit Obligation, Benefits Paid		$ (14.1)		$ (14.2)
Defined Benefit Plan, Plan Assets, Benefits Paid		14.1		14.2
Accumulated Benefit Obligation		475.2		610.8
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment		0		0
Plan curtailments		0		0
Pension Plan [Member] | Og and E [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation, Beginning		484.1		462
Service cost		7.7		9.2		$ 9
Interest cost		9.7		12.6		15.6
Plan settlements		(120.4)		(33.5)
Actuarial (gains) losses		(6)		41
Benefit Obligation, Ending		363.2		484.1		462
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		420.3		399.1
Actual return on plans' assets		35		57
Employer contributions		30		10
Plan settlements		(120.4)		(33.5)
Fair Value of Plan Assets, Ending		353		420.3		399.1
Funded Status of Plan		(10.2)		(63.8)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost		7.7		9.2		9
Interest cost		9.7		12.6		15.6
Expected return on plan assets		(24.7)		(27.9)		(27.6)
Amortization of unrecognized prior service cost	[1]	0		0		0
Curtailment		0		0		0
Settlement cost		33.1		11.4		16.4
Net periodic benefit cost		32.8		22.5		26.3
Net Periodic Benefit Cost, Net of Unconsolidated Affiliates		39.3		28.4		30.8
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Capitalized Portion of Net Periodic Benefit Cost		2.9		3.1		3
Defined Benefit Plan, Benefit Obligation, Benefits Paid		(11.9)		(12.3)
Defined Benefit Plan, Plan Assets, Benefits Paid		11.9		12.3
Accumulated Benefit Obligation		341		454.7
Plan curtailments		0		0
Pension Plan [Member] | Equity Funds [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning	[3]	25.4
Fair Value of Plan Assets, Ending		23.6	[4]	25.4	[3]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Alternative Investment		23.6	[4],[5]	25.4	[3],[6]
Pension Plan [Member] | Money market funds [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		8.8
Fair Value of Plan Assets, Ending		5.5		8.8
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Alternative Investment		5.5	[5]	8.8	[6]
Pension Plan [Member] | Total Plan assets [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		570.3
Fair Value of Plan Assets, Ending		486		570.3
Pension Plan [Member] | Total Plan assets [Member] | Og and E [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		420.3
Fair Value of Plan Assets, Ending		353		420.3
Pension Plan [Member] | Plan Assets Attributable to Affiliates
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		(150)
Fair Value of Plan Assets, Ending		(133)		(150)
Pension Plan [Member] | Fair Value, Inputs, Level 1 [Member] | Equity Funds [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning	[3]	0
Fair Value of Plan Assets, Ending		0	[4]	0	[3]
Pension Plan [Member] | Fair Value, Inputs, Level 1 [Member] | Money market funds [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		0
Fair Value of Plan Assets, Ending		0		0
Pension Plan [Member] | Fair Value, Inputs, Level 2 [Member] | Equity Funds [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning	[3]	0
Fair Value of Plan Assets, Ending		0	[4]	0	[3]
Pension Plan [Member] | Fair Value, Inputs, Level 2 [Member] | Money market funds [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		0
Fair Value of Plan Assets, Ending		0		0
Pension Plan [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		0
Fair Value of Plan Assets, Ending		0		0
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation, Beginning		144.5		136.5
Service cost		0.2		0.2		0.2
Interest cost		3.4		4.2		5.6
Actuarial (gains) losses		(3.7)		7.3
Benefit Obligation, Ending		137.3		144.5		136.5
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		47.6		47
Actual return on plans' assets		(0.5)		1.2
Employer contributions		6.2		7.1
Fair Value of Plan Assets, Ending		44.3		47.6		47
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost		0.2		0.2		0.2
Interest cost		3.4		4.2		5.6
Expected return on plan assets		(1.8)		(1.8)		(1.9)
Amortization of unrecognized prior service cost	[1]	(6.9)		(8.4)		(8.4)
Curtailment		0		(1.5)		0
Net periodic benefit cost		(2.3)		(2.3)		(2.5)
Amount paid by unconsolidated affiliates	[7]	(0.5)		(0.7)		(0.6)
Net Periodic Benefit Cost, Net of Unconsolidated Affiliates		(1.8)		(1.6)		(1.9)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Capitalized Portion of Net Periodic Benefit Cost		$ 0.2		$ 0.2		$ 0.2
Assumptions Used Calculating Benefit Obligation, Discount Rate		2.80%		2.45%		3.25%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate		2.45%		3.25%		4.30%
Health Care Cost Trend Rate Assumed for Next Fiscal Year		6.50%
Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Return on Assets		4.00%		4.00%		4.00%
Defined Benefit Plan, Benefit Obligation, Benefits Paid		$ (12.5)		$ (11)
Defined Benefit Plan, Plan Assets, Benefits Paid		12.5		11
Accumulated Benefit Obligation		93		96.9
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment		0		0
Plan curtailments		1.9		4
Other Postretirement Benefit Plans, Defined Benefit [Member] | Og and E [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation, Beginning		109.5		104.7
Service cost		0.1		0.2		$ 0.2
Interest cost		2.6		3.2		4.3
Actuarial (gains) losses		(2.5)		4.5
Benefit Obligation, Ending		102.4		109.5		104.7
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		42.7		41.9
Actual return on plans' assets		(0.5)		1.1
Employer contributions		5		5.9
Fair Value of Plan Assets, Ending		39.9		42.7		41.9
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost		0.1		0.2		0.2
Interest cost		2.6		3.2		4.3
Expected return on plan assets		(1.7)		(1.7)		(1.7)
Amortization of unrecognized prior service cost	[1]	(5)		(6.1)		(6.1)
Curtailment		0		(1.3)		0
Net periodic benefit cost		(1.3)		(1)		(1.2)
Net Periodic Benefit Cost, Net of Unconsolidated Affiliates		(1.8)		(1.5)		(1.8)
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Capitalized Portion of Net Periodic Benefit Cost		0.1		0.1		0.1
Defined Benefit Plan, Benefit Obligation, Benefits Paid		(9.9)		(8.6)
Defined Benefit Plan, Plan Assets, Benefits Paid		9.9		8.6
Accumulated Benefit Obligation		62.5		66.8
Plan curtailments		0		3.1
Other Postretirement Benefit Plans, Defined Benefit [Member] | Group Retiree Medical Insurance Contract [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		33.4
Fair Value of Plan Assets, Ending		28.1		33.4
Other Postretirement Benefit Plans, Defined Benefit [Member] | U.S. Equity Mutual Funds Investment [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		14.2
Fair Value of Plan Assets, Ending		16.2		14.2
Other Postretirement Benefit Plans, Defined Benefit [Member] | Fair Value, Inputs, Level 1 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		14.2
Fair Value of Plan Assets, Ending		16.2		14.2
Other Postretirement Benefit Plans, Defined Benefit [Member] | Fair Value, Inputs, Level 1 [Member] | Group Retiree Medical Insurance Contract [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		0
Fair Value of Plan Assets, Ending		0		0
Other Postretirement Benefit Plans, Defined Benefit [Member] | Fair Value, Inputs, Level 1 [Member] | U.S. Equity Mutual Funds Investment [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		14.2
Fair Value of Plan Assets, Ending		16.2		14.2
Other Postretirement Benefit Plans, Defined Benefit [Member] | Fair Value, Inputs, Level 2 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		0
Fair Value of Plan Assets, Ending		0		0
Other Postretirement Benefit Plans, Defined Benefit [Member] | Fair Value, Inputs, Level 3 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		33.4
Fair Value of Plan Assets, Ending		28.1		33.4
Other Postretirement Benefit Plans, Defined Benefit [Member] | Fair Value, Inputs, Level 3 [Member] | Group Retiree Medical Insurance Contract [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		33.4
Fair Value of Plan Assets, Ending		28.1		33.4
Other Postretirement Benefit Plans, Defined Benefit [Member] | Fair Value, Inputs, Level 3 [Member] | U.S. Equity Mutual Funds Investment [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		0
Fair Value of Plan Assets, Ending		0		0
Other Postretirement Benefit Plans, Defined Benefit [Member] | Fair Value, Inputs, Level 1, 2 and 3 [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		47.6
Fair Value of Plan Assets, Ending		44.3		47.6
Other Postretirement Benefit Plans, Defined Benefit [Member] | Fair Value, Inputs, Level 1, 2 and 3 [Member] | Og and E [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		42.7
Fair Value of Plan Assets, Ending		39.9		42.7
Other Postretirement Benefit Plans, Defined Benefit [Member] | Fair Value, Inputs, Level 1, 2 and 3 [Member] | OGE Energy [Member]
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		(4.9)
Fair Value of Plan Assets, Ending		(4.4)		(4.9)
Other Pension Plan [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation, Beginning		7.8		10.3
Service cost		0.8		0.8		0.5
Interest cost		0.1		0.2		0.4
Plan settlements		(4.6)		(5.3)
Actuarial (gains) losses		0.5		1.6
Benefit Obligation, Ending		5.9		7.8		10.3
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		0		0
Actual return on plans' assets		0		0
Employer contributions		4.6		5.3
Plan settlements		(4.6)		(5.3)
Fair Value of Plan Assets, Ending		0		0		0
Funded Status of Plan		(5.9)		(7.8)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost		0.8		0.8		0.5
Interest cost		0.1		0.2		0.4
Expected return on plan assets		0		0		0
Amortization of unrecognized prior service cost	[1]	0.1		0		0
Curtailment		0		(0.2)		0
Settlement cost		2.1		2.7		0.5
Net periodic benefit cost		3.3		4.4		1.9
Amount paid by unconsolidated affiliates	[2]	0.1		0.1		0.1
Net Periodic Benefit Cost, Net of Unconsolidated Affiliates		3.2		4.3		1.8
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Defined Benefit Plan, Benefit Obligation, Benefits Paid		0		0
Defined Benefit Plan, Plan Assets, Benefits Paid		0		0
Accumulated Benefit Obligation		5.4		6.9
Defined Benefit Plan, Benefit Obligation, Increase (Decrease) for Plan Amendment		1.4		0
Plan curtailments		(0.1)		0.2
Other Pension Plan [Member] | Og and E [Member]
Defined Benefit Plan, Change in Benefit Obligation [Roll Forward]
Benefit Obligation, Beginning		3		6.1
Service cost		0		0.1		0.2
Interest cost		0		0.1		0.2
Plan settlements		(2.9)		(4.5)
Actuarial (gains) losses		0.4		1.2
Benefit Obligation, Ending		0.5		3		6.1
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Fair Value of Plan Assets, Beginning		0		0
Actual return on plans' assets		0		0
Employer contributions		2.9		4.5
Plan settlements		(2.9)		(4.5)
Fair Value of Plan Assets, Ending		0		0		0
Funded Status of Plan		(0.5)		(3)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost		0		0.1		0.2
Interest cost		0		0.1		0.2
Expected return on plan assets		0		0		0
Amortization of unrecognized prior service cost	[1]	0		0		0
Curtailment		0		0		0
Settlement cost		1.6		2.4		0.5
Net periodic benefit cost		1.7		3		1.2
Net Periodic Benefit Cost, Net of Unconsolidated Affiliates		3.2		4.3		1.7
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Defined Benefit Plan, Benefit Obligation, Benefits Paid		0		0
Defined Benefit Plan, Plan Assets, Benefits Paid		0		0
Accumulated Benefit Obligation		0.4		2.9
Plan curtailments		0		0
OKLAHOMA | Pension Plan [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Settlement cost	[8]	37.9		21.6		17.9
OKLAHOMA | Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Settlement cost	[9]	$ 0		$ (1.4)		$ 0
[1]	Unamortized prior service cost is amortized on a straight-line basis over the average remaining service period to the first eligibility age of participants who are expected to receive a benefit and are active at the date of the plan amendment.
[2]	"Amount paid by unconsolidated affiliates" is only applicable to OGE Energy. "Amount allocated from OGE Energy" is only applicable to OG&E.
[3]	This category represents units of participation in a commingled fund that primarily invested in stocks of international companies and emerging markets.
[4]	This category represents units of participation in a commingled fund that primarily invested in stocks of international companies and emerging markets.
[5]	GAAP allows the measurement of certain investments that do not have a readily determinable fair value at the net asset value. These investments do not consider the observability of inputs; therefore, they are not included within the fair value hierarchy.
[6]	GAAP allows the measurement of certain investments that do not have a readily determinable fair value at the net asset value. These investments do not consider the observability of inputs; therefore, they are not included within the fair value hierarchy.
[7]	"Amount paid by unconsolidated affiliates" is only applicable to OGE Energy. "Amount allocated from OGE Energy" is only applicable to OG&E.
[8]	Included in the pension regulatory asset or liability in each jurisdiction, as indicated in the regulatory assets and liabilities table in Note 1.
[9]	Included in the pension regulatory asset or liability in each jurisdiction, as indicated in the regulatory assets and liabilities table in Note 1.

Report of Business Segments (De

Report of Business Segments (Details) - USD ($) $ in Millions		11 Months Ended		12 Months Ended
		Dec. 02, 2021		Dec. 31, 2021	Dec. 31, 2020		Dec. 31, 2019
Segment Reporting Information [Line Items]
Operating revenues				$ 3,653.7	$ 2,122.3		$ 2,231.6
Fuel, purchased power and direct transmission expense				2,127.6	644.6		786.9
Other operation and maintenance				463.1	462.8		491.8
Depreciation and amortization				416	391.3		355
Taxes other than income				102.8	101.4		93.6
Operating income (loss)				544.2	522.2		504.3
Equity in earnings of unconsolidated affiliates		$ 169.8	[1]	169.8	(668)	[1],[2]	113.9	[1]
Other income (expense)				(21.6)	3.2		(6.9)
Interest expense				158.3	158.5		147.9
Income tax expense (benefit)				141.2	(127.4)		29.8
NET INCOME (LOSS)				737.3	(173.7)		433.6
Investment in unconsolidated affiliates				0	374.3		1,132.9
Total assets				12,606.4	10,718.8		11,024.3
Capital expenditures				778.5	650.5		635.5
Equity Method Investment, Other than Temporary Impairment	[3]	$ 0			(780)		0
Gain (Loss) on Disposition of Assets				344.4	0		0
Electric Utility [Member]
Segment Reporting Information [Line Items]
Operating revenues				3,653.7	2,122.3		2,231.6
Fuel, purchased power and direct transmission expense				2,127.6	644.6		786.9
Other operation and maintenance				464.7	464.4		492.5
Depreciation and amortization				416	391.3		355
Taxes other than income				99.3	97.2		89.5
Operating income (loss)				546.1	524.8		507.7
Equity in earnings of unconsolidated affiliates				0	0	[2]	0
Other income (expense)				7.7	4.1		3.1
Interest expense				152	154.8		140.5
Income tax expense (benefit)				41.8	34.7		20.1
NET INCOME (LOSS)				360	339.4		350.2
Investment in unconsolidated affiliates					0		0
Total assets				11,688	10,489		10,076.6
Capital expenditures				778.5	650.5		635.5
Gain (Loss) on Disposition of Assets				0
Natural Gas Midstream Operations [Member]
Segment Reporting Information [Line Items]
Operating revenues				0	0		0
Fuel, purchased power and direct transmission expense				0	0		0
Other operation and maintenance				1.6	1.7		2.8
Depreciation and amortization				0	0		0
Taxes other than income				0.2	0.4		0.4
Operating income (loss)				(1.8)	(2.1)		(3.2)
Equity in earnings of unconsolidated affiliates				169.8	(668)	[2]	113.9
Other income (expense)				(26.4)	(2.9)		(8.6)
Interest expense				0	0		0
Income tax expense (benefit)				101	(158)		20.7
NET INCOME (LOSS)				385	(515)		81.4
Investment in unconsolidated affiliates					374.3		1,132.9
Total assets				786.6	378.1		1,135.4
Capital expenditures				0	0		0
Gain (Loss) on Disposition of Assets				344.4
Other Operations [Member]
Segment Reporting Information [Line Items]
Operating revenues				0	0		0
Fuel, purchased power and direct transmission expense				0	0		0
Other operation and maintenance				(3.2)	(3.3)		(3.5)
Depreciation and amortization				0	0		0
Taxes other than income				3.3	3.8		3.7
Operating income (loss)				(0.1)	(0.5)		(0.2)
Equity in earnings of unconsolidated affiliates				0	0	[2]	0
Other income (expense)				(2)	3.6		2.2
Interest expense				7.2	5.3		11
Income tax expense (benefit)				(1.6)	(4.1)		(11)
NET INCOME (LOSS)				(7.7)	1.9		2
Investment in unconsolidated affiliates					0		0
Total assets				350.3	116.4		107
Capital expenditures				0	0		0
Gain (Loss) on Disposition of Assets				0
Eliminations [Member]
Segment Reporting Information [Line Items]
Operating revenues				0	0		0
Fuel, purchased power and direct transmission expense				0	0		0
Other operation and maintenance				0	0		0
Depreciation and amortization				0	0		0
Taxes other than income				0	0		0
Operating income (loss)				0	0		0
Equity in earnings of unconsolidated affiliates				0	0	[2]	0
Other income (expense)				(0.9)	(1.6)		(3.6)
Interest expense				(0.9)	(1.6)		(3.6)
Income tax expense (benefit)				0	0		0
NET INCOME (LOSS)				0	0		0
Investment in unconsolidated affiliates					0		0
Total assets				(218.5)	(264.7)		(294.7)
Capital expenditures				0	$ 0		$ 0
Gain (Loss) on Disposition of Assets				$ 0
[1]	For the year ended December 31, 2020, Enable recorded a $225.0 million impairment on its SESH equity method investment. Enable estimated the fair value of this equity method investment was below the carrying value at September 30, 2020 and concluded the decline in value was other than temporary due to the expiration of a transportation contract and the current status of renewal negotiations. The impairment ran through OGE Energy's portion of Enable net income and was offset by basis differences that flow through the amortization of basis difference and dilution recognition line item above
[2]	In March 2020, OGE Energy recorded a $780.0 million impairment on its investment in Enable, as further discussed in Notes 5 and 7.
[3]	Effective March 31, 2020, OGE Energy estimated the fair value of its investment in Enable was below the book value and concluded the decline in value was not temporary due to the severity of the decline and recent rapid deterioration, as well as the near term future outlook, of the midstream oil and gas industry. Accordingly, OGE Energy recorded a $780.0 million impairment on its investment in Enable in 2020. Further information concerning the fair value method used to measure the impairment on OGE Energy's investment in Enable can be found in Note 7.

Commitments and Contingencies_2

Commitments and Contingencies (Details) $ in Millions	12 Months Ended
	Dec. 31, 2021USD ($)	Dec. 31, 2020USD ($)	Dec. 31, 2019USD ($)
Loss Contingencies [Line Items]
Operating Leases, Future Minimum Payments Due, Next Twelve Months	$ 156
Operating Leases, Future Minimum Payments, Due in Two Years	109
Operating Leases, Future Minimum Payments, Due in Three Years	102.8
Operating Leases, Future Minimum Payments, Due in Four Years	105.9
Operating Leases, Future Minimum Payments, Due in Five Years	91.7
Operating Leases, Future Minimum Payments Due	565.4
Utilities Operating Expense, Purchased Power under Long-term Contracts	55.8	$ 57.3	$ 57.7
OG&E minimum fuel purchase commitments [Member]
Loss Contingencies [Line Items]
Operating Leases, Future Minimum Payments Due	228.5
Purchase Obligation, Due in Next Twelve Months	97.7
Unrecorded Unconditional Purchase Obligation, Due within Two Years	50.4
Unrecorded Unconditional Purchase Obligation, Due within Three Years	31.2
Unrecorded Unconditional Purchase Obligation, Due within Four Years	24.6
Unrecorded Unconditional Purchase Obligation, Due within Five Years	24.6
OG&E expected wind purchase commitments [Member]
Loss Contingencies [Line Items]
Operating Leases, Future Minimum Payments Due	282.5
Purchase Obligation, Due in Next Twelve Months	55.6
Unrecorded Unconditional Purchase Obligation, Due within Two Years	56
Unrecorded Unconditional Purchase Obligation, Due within Three Years	56.6
Unrecorded Unconditional Purchase Obligation, Due within Four Years	56.9
Unrecorded Unconditional Purchase Obligation, Due within Five Years	57.4
OG&E long-term service agreement commitments [Member]
Loss Contingencies [Line Items]
Operating Leases, Future Minimum Payments Due	54.4
Purchase Obligation, Due in Next Twelve Months	2.7
Unrecorded Unconditional Purchase Obligation, Due within Two Years	2.6
Unrecorded Unconditional Purchase Obligation, Due within Three Years	15
Unrecorded Unconditional Purchase Obligation, Due within Four Years	24.4
Unrecorded Unconditional Purchase Obligation, Due within Five Years	9.7
OG&E total cogeneration payments [Member]
Loss Contingencies [Line Items]
Utilities Operating Expense, Purchased Power under Long-term Contracts		14.7
OG&E capacity payments [Member]
Loss Contingencies [Line Items]
Utilities Operating Expense, Purchased Power under Long-term Contracts		7.4
CPV Keenan [Member]
Loss Contingencies [Line Items]
Utilities Operating Expense, Purchased Power under Long-term Contracts	27.3	27.5	27.2
Edison Mission Energy [Member]
Loss Contingencies [Line Items]
Utilities Operating Expense, Purchased Power under Long-term Contracts	21.7	22.8	23.1
NextEra Energy [Member]
Loss Contingencies [Line Items]
Utilities Operating Expense, Purchased Power under Long-term Contracts	$ 6.8	$ 7	$ 7.4
OG&E long-term service agreement commitments [Member] | McClain Plant [Member]
Loss Contingencies [Line Items]
Factored-Fired Hours	128,000
Factored-Fired Starts	4,800
OG&E long-term service agreement commitments [Member] | Redbud Plant [Member]
Loss Contingencies [Line Items]
Factored-Fired Hours	144,000
Factored-Fired Starts	4,500
Additional Factored-Fired Hours	24,000

Rate Matters and Regulation (De

Rate Matters and Regulation (Details) $ in Millions	12 Months Ended
	Dec. 31, 2021USD ($)
Estimated Refund to SPP	$ 13
Securitization Authorization Requested	760
Securitization Fuel Purchase Request	748.9
Securitization Fuel Cost Request Prudency	739.1
Plan Investments for Customers	28
Requested Recovery of Capital Investment	1,200
Grid Enhancement
Revenue Requirement	7
Minimum [Member]
Lost Revenue on Plant Investments for Customers	28.9
Maximum [Member]
Lost Revenue on Plant Investments for Customers	39.3
In Favor Cooperatives [Member]
Plan Investments for Customers	11.7
In Favor Cooperatives [Member] | Minimum [Member]
Lost Revenues on Plant Investments for Customers	2.9
In Favor Cooperatives [Member] | Maximum [Member]
Lost Revenues on Plant Investments for Customers	4.5
Impact to Company [Member]
Estimated Refund to SPP	5
Customer Impact [Member]
Estimated Refund to SPP	$ 8
Oklahoma Corporation Commission [Member]
OG&E's Jurisdictional Revenues	89.00%
Arkansas Public Service Commission [Member]
OG&E's Jurisdictional Revenues	8.00%
Federal Energy Regulatory Commission [Member]
OG&E's Jurisdictional Revenues	3.00%
OKLAHOMA
Public Utilities, Requested Rate Increase (Decrease), Amount	$ 163.5
Public Utilities, Requested Return on Equity, Percentage	10.20%
Common Equity Percentage which ROE is based	53.37%
ARKANSAS
Public Utilities, Requested Rate Increase (Decrease), Amount	$ 4.2
Public Utilities, Approved Rate Increase (Decrease), Amount	$ 6.7

Schedule II (Details)

Schedule II (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
SEC Schedule, 12-09, Valuation and Qualifying Accounts Disclosure [Line Items]
Valuation Allowances and Reserves, Beginning Balance		$ 2.6	$ 1.5	$ 1.7
Valuation Allowances and Reserves, Charged to Cost and Expense		3.2	3	2.2
SEC Schedule, 12-09, Valuation Allowances and Reserves, Deduction	[1]	3.4	1.9	2.4
Valuation Allowances and Reserves, Ending Balance		$ 2.4	$ 2.6	$ 1.5
[1]	Uncollectible accounts receivable written off, net of recoveries.