OGE Energy (OGE) 10-Q 6 Aug 20 2020 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information Document	6 Months Ended
	Jun. 30, 2020shares
Entity Information [Line Items]
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Jun. 30, 2020
Document Transition Report	false
Entity File Number	1-12579
Entity Registrant Name	OGE ENERGY CORP.
Entity Incorporation, State or Country Code	OK
Entity Tax Identification Number	73-1481638
Entity Central Index Key	0001021635
Current Fiscal Year End Date	--12-31
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q2
Amendment Flag	false
Title of 12(b) Security	Common Stock
Trading Symbol	OGE
Security Exchange Name	NYSE
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Shell Company	false
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Address, Address Line One	321 North Harvey
Entity Address, Address Line Two	P.O. Box 321
Entity Address, City or Town	Oklahoma City
Entity Address, State or Province	OK
Entity Address, Postal Zip Code	73101-0321
City Area Code	405
Local Phone Number	553-3000
Entity Common Stock, Shares Outstanding	200,169,838

CONDENSED CONSOLIDATED STATEMEN

CONDENSED CONSOLIDATED STATEMENTS OF INCOME (Unaudited) - USD ($) shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020		Jun. 30, 2019
Revenues from contracts with customers	$ 492	$ 501.1	$ 912.4		$ 978.5
Other revenues	11.5	12.6	22.4		25.2
Operating revenues	503.5	513.7	934.8		1,003.7
COST OF SALES	137.4	178.7	272.4		391.3
OPERATING EXPENSES
Other operation and maintenance	117.5	119.8	237.5		238.8
Depreciation and amortization	97.3	84.3	191.7		166.7
Taxes other than income	25.9	20.9	51.5		47.2
Operating expenses	240.7	225	480.7		452.7
OPERATING INCOME	125.4	110	181.7		159.7
OTHER INCOME (EXPENSE)
Equity in earnings (losses) of unconsolidated affiliates	26.9	35.8	(719.6)	[1]	66.5
Allowance for equity funds used during construction	1.3	1.2	2.6		2.7
Other net periodic benefit expense	(1)	(0.3)	(1.5)		(7.3)
Other income	14.1	5	21.5		11.7
Other expense	(12.4)	(4.4)	(18.5)		(10.1)
Net other income (expense)	28.9	37.3	(715.5)		63.5
INTEREST EXPENSE
Interest on long-term debt	38.8	31.8	75.4		64.4
Allowance for borrowed funds used during construction	(0.5)	(0.6)	(1)		(1.6)
Interest on short-term debt and other interest charges	2.5	4.7	4.7		7.7
Interest expense	40.8	35.9	79.1		70.5
INCOME (LOSS) BEFORE TAXES	113.5	111.4	(612.9)		152.7
INCOME TAX EXPENSE (BENEFIT)	27.6	11.2	(207)		5.4
NET INCOME (LOSS)	$ 85.9	$ 100.2	$ (405.9)		$ 147.3
BASIC AVERAGE COMMON SHARES OUTSTANDING	200.2	200.2	200.2		200.1
DILUTED AVERAGE COMMON SHARES OUTSTANDING	200.5	200.6	200.2		200.5
BASIC EARNINGS (LOSS) PER AVERAGE COMMON SHARE	$ 0.43	$ 0.50	$ (2.03)		$ 0.74
DILUTED EARNINGS (LOSS) PER AVERAGE COMMON SHARE	$ 0.43	$ 0.50	$ (2.03)		$ 0.73
[1]	In March 2020, the Company recorded a $780.0 million impairment on its investment in Enable, as further discussed in Notes 4 and 5.

CONDENSED CONSOLIDATED STATEM_2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Other comprehensive income (loss), net of tax
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ 85.9	$ 100.2	$ (405.9)	$ 147.3
Pension Plan and Restoration of Retirement Income Plan:
Amortization of deferred net loss, net of tax of $0.3, $0.3, $0.6 and $0.5, respectively	1.2	1	2	1.7
Settlement cost, net of tax of $0.1, $0.1, $0.1 and $2.3, respectively	0.2	0.5	0.2	7.1
Postretirement Benefit Plans:
Amortization of prior service credit, net of tax of ($0.1), ($0.1), ($0.3) and ($0.2), respectively	(0.4)	(0.4)	(0.8)	(0.9)
Amortization of deferred net gain, net of tax of $0.0, $0.0, $0.0 and $0.0, respectively	0.1	0.1	0.1	0.1
Other comprehensive loss from unconsolidated affiliates, net of tax of $0.0, $0.0, ($0.4) and $0.0, respectively	0	0	1.3	0
Other comprehensive income (loss), net of tax	0.9	1	0	7.8
Comprehensive income (loss)	$ 86.8	$ 101.2	$ (405.9)	$ 155.1

CONDENSED CONSOLIDATED STATEM_3

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) Parenthetical - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Pension Plan and Restoration of Retirement Income Plan:
Amortization of deferred net loss	$ 0.3	$ 0.3	$ 0.6	$ 0.5
Postretirement Benefit Plans:
Amortization of prior service cost	(0.1)	(0.1)	(0.3)	(0.2)
Other Comprehensive Income Reclassification Of Defined Benefit Postretirement Plans Net Gain Loss Recognized In Net Periodic Benefit Cost Tax	0	0	0	0
Other Comprehensive Income (Loss), before Tax, Portion Attributable to Noncontrolling Interest	0	0	(0.4)	0
Pension Plan [Member]
Other Comprehensive Income (Loss), Defined Benefit Plan, Adjustment for Settlement or Curtailment Gain (Loss), Tax	$ 0.1	$ 0.1	$ 0.1	$ 2.3

CONDENSED CONSOLIDATED STATEM_4

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2020		Jun. 30, 2019
Adjustments to reconcile net income (loss) to net cash provided from operating activities:
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ (405.9)		$ 147.3
Depreciation and amortization	191.7		166.7
Deferred income taxes and investment tax credits, net	(226.7)		(1.9)
Equity in (earnings) losses of unconsolidated affiliates	719.6	[1]	(66.5)
Distributions from unconsolidated affiliates	55		70.6
Allowance for equity funds used during construction	(2.6)		(2.7)
Stock-based compensation expense	4.3		5.9
Regulatory assets	(6.1)		(25.6)
Regulatory liabilities	(26.7)		(21.1)
Other assets	1.3		(3.2)
Other liabilities	(15.6)		13.9
Change in certain current assets and liabilities:
Accounts receivable and accrued unbilled revenues, net	(35.8)		(12.5)
Increase (Decrease) in Income Taxes Receivable	10.4		3.6
Fuel, materials and supplies inventories	(1.5)		7.2
Fuel recoveries	71.9		(28.9)
Other current assets	(10.8)		(4.5)
Accounts payable	(51.2)		(83.4)
Other current liabilities	(8)		(36.1)
Net cash provided from operating activities	263.3		128.8
CASH FLOWS FROM INVESTING ACTIVITIES
Capital expenditures (less allowance for equity funds used during construction)	(280.8)		(314.5)
Investment in unconsolidated affiliates	(1.5)		(3.2)
Net cash used in investing activities	(282.3)		(317.7)
CASH FLOWS FROM FINANCING ACTIVITIES
Proceeds from Issuance of Long-term Debt	297.2		295.9
Increase (decrease) in short-term debt	(37)		207.5
Payment of long-term debt	0		(250)
Dividends paid on common stock	(156.8)		(148.6)
Net cash provided from financing activities	86.5		94.6
NET CHANGE IN CASH AND CASH EQUIVALENTS	67.5		(94.3)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	0		94.3
CASH AND CASH EQUIVALENTS AT END OF PERIOD	67.5		0
Proceeds from (Payments for) Other Financing Activities	(7.2)		(10.2)
Treasury Stock, Value, Acquired, Cost Method	$ (9.7)		$ 0
[1]	In March 2020, the Company recorded a $780.0 million impairment on its investment in Enable, as further discussed in Notes 4 and 5.

CONDENSED CONSOLIDATED BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
CURRENT ASSETS
Cash and cash equivalents	$ 67.5	$ 0
Accounts receivable, less reserve of $2.0 and $1.5, respectively	160.6	153.8
Accrued unbilled revenues	93.7	64.7
Income taxes receivable	0.5	10.9
Fuel inventories	42.7	46.3
Materials and supplies, at average cost	98.8	90.6
Fuel clause under recoveries	0	39.5
Other	35.2	24.4
Total current assets	499	430.2
OTHER PROPERTY AND INVESTMENTS
Investment in unconsolidated affiliates	376.5	1,151.5
Other	79.2	82.7
Total other property and investments	455.7	1,234.2
PROPERTY, PLANT AND EQUIPMENT
In service	13,005.4	12,771.1
Construction work in progress	124	141.6
Total property, plant and equipment	13,129.4	12,912.7
Less: accumulated depreciation	3,957.3	3,868.1
Net property, plant and equipment	9,172.1	9,044.6
DEFERRED CHARGES AND OTHER ASSETS
Regulatory assets	299.4	306
Other	12.9	9.3
Total deferred charges and other assets	312.3	315.3
TOTAL ASSETS	10,439.1	11,024.3
CURRENT LIABILITIES
Short-term debt	75	112
Accounts payable	144.2	194.9
Dividends payable	77.6	77.6
Customer deposits	82.7	83
Accrued taxes	57.5	41.9
Accrued interest	40.3	37.9
Accrued compensation	38.7	40.6
Fuel clause over recoveries	37.2	4.8
Other	41.4	65.2
Total current liabilities	594.6	657.9
LONG-TERM DEBT	3,493.4	3,195.2
DEFERRED CREDITS AND OTHER LIABILITIES
Accrued benefit obligations	214.3	225
Deferred income taxes	1,165.7	1,375.8
Deferred investment tax credits	7.1	7.1
Regulatory liabilities	1,206.2	1,223.5
Other	193.6	200.3
Total deferred credits and other liabilities	2,786.9	3,031.7
Total liabilities	6,874.9	6,884.8
COMMITMENTS AND CONTINGENCIES (NOTE 13)
STOCKHOLDERS' EQUITY
Common stockholders' equity	1,119.1	1,131.3
Retained earnings	2,473.3	3,036.1
Accumulated other comprehensive loss, net of tax	(27.9)	(27.9)
Total stockholders' equity	3,564.2	4,139.5
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	10,439.1	11,024.3
Treasury Stock, Carrying Basis	$ 0.3	$ 0

CONDENSED CONSOLIDATED BALANC_2

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) Parenthetical - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Accounts Receivable, Allowance for Credit Loss	$ 2	$ 1.5

CONDENSED CONSOLIDATED STATEM_5

CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Unaudited) - USD ($) shares in Thousands, $ in Millions	Total	Common Stock	Premium on Common Stock	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Treasury Stock [Member]
Changes in Stockholders' Equity
Balance	$ 4,005.1	$ 2	$ 1,125.7	$ 2,906.3	$ (28.9)	$ 0
Common Stock, Shares, Outstanding		199,700
Treasury Stock, Common, Shares						0
Net Income (Loss), Including portion attributable to noncontrolling interest, Number of Shares		0				0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	47.1	$ 0	0	47.1	0	$ 0
Other Comprehensive Income (Loss), Net of Tax, Number of Shares		0				0
Dividends, Common Stock, Cash, Number of Shares		0				0
Other comprehensive income, net of tax	6.8	$ 0	0	0	6.8	$ 0
Dividends declared on common stock ($0.3875 per share)	(75.6)	$ 0	0	(75.6)	0	$ 0
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition, Number of Shares		500				0
Stock-based compensation	(7.2)	$ 0	(7.2)	0	0	$ 0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	147.3			147.3
Other comprehensive income, net of tax	7.8
Treasury Stock, Value, Acquired, Cost Method	0
Balance	3,976.2	$ 2	1,118.5	2,877.8	(22.1)	$ 0
Common Stock, Shares, Outstanding		200,200
Treasury Stock, Common, Shares						0
Net Income (Loss), Including portion attributable to noncontrolling interest, Number of Shares		0				0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	100.2	$ 0	0	100.2	0	$ 0
Other Comprehensive Income (Loss), Net of Tax, Number of Shares		0				0
Dividends, Common Stock, Cash, Number of Shares		0				0
Other comprehensive income, net of tax	1	$ 0	0	0	1	$ 0
Dividends declared on common stock ($0.3875 per share)	(73.1)	$ 0	0	(73.1)	0	$ 0
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition, Number of Shares		0				0
Stock-based compensation	2.9	$ 0	2.9	0	0	$ 0
Balance	4,007.2	$ 2	1,121.4	2,904.9	(21.1)	$ 0
Common Stock, Shares, Outstanding		200,200
Treasury Stock, Common, Shares						0
Balance	4,139.5	$ 2	1,129.3	3,036.1	(27.9)	$ 0
Common Stock, Shares, Outstanding		200,100
Treasury Stock, Common, Shares						0
Net Income (Loss), Including portion attributable to noncontrolling interest, Number of Shares		0				0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	(491.8)	$ 0	0	(491.8)	0	$ 0
Other Comprehensive Income (Loss), Net of Tax, Number of Shares		0				0
Dividends, Common Stock, Cash, Number of Shares		0				0
Other comprehensive income, net of tax	(0.9)	$ 0	0	0	(0.9)	$ 0
Dividends declared on common stock ($0.3875 per share)	(79.3)	$ 0	0	(79.3)	0	$ 0
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition, Number of Shares		0				(200)
Stock-based compensation	(5.1)	$ 0	(14.5)	0	0	$ 9.4
Treasury Stock, Shares, Acquired		0				200
Treasury Stock, Value, Acquired, Cost Method	(9.7)	$ 0	0	0	0	$ (9.7)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	(405.9)			(405.9)
Other comprehensive income, net of tax	$ 0
Treasury Stock, Shares, Acquired	255
Treasury Stock, Value, Acquired, Cost Method	$ 9.7
Balance	3,552.7	$ 2	1,114.8	2,465	(28.8)	$ (0.3)
Common Stock, Shares, Outstanding		200,100
Treasury Stock, Common, Shares						0
Net Income (Loss), Including portion attributable to noncontrolling interest, Number of Shares		0				0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	85.9	$ 0	0	85.9	0	$ 0
Other Comprehensive Income (Loss), Net of Tax, Number of Shares		0				0
Dividends, Common Stock, Cash, Number of Shares		0				0
Other comprehensive income, net of tax	0.9	$ 0	0	0	0.9	$ 0
Dividends declared on common stock ($0.3875 per share)	(77.6)	$ 0	0	(77.6)	0	$ 0
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition, Number of Shares		0				0
Stock-based compensation	2.3	$ 0	2.3	0	0	$ 0
Balance	$ 3,564.2	$ 2	$ 1,117.1	$ 2,473.3	$ (27.9)	$ (0.3)
Common Stock, Shares, Outstanding		200,100
Treasury Stock, Common, Shares						0

CONDENSED CONSOLIDATED STATEM_6

CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Unaudited) Parenthetical - $ / shares	3 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019
Statement of Stockholders' Equity [Abstract]
Common Stock, Dividends, Per Share, Declared	$ 0.3875	$ 0.3875	$ 0.365	$ 0.3650

Summary of Significant Accounti

Summary of Significant Accounting Policies	6 Months Ended
	Jun. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Significant Accounting Policies [Text Block]	Summary of Significant Accounting Policies The Company's significant accounting policies are detailed in "Note 1. Summary of Significant Accounting Policies" in the Company's 2019 Form 10-K . Changes to the Company's accounting policies as a result of adopting ASU 2016-13, "Financial Instruments - Credit Losses: Measurement of Credit Losses on Financial Information" are incorporated within "Allowance for Uncollectible Accounts Receivables" below and discussed in Note 2. 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 is a summary of OG&E's regulatory assets and liabilities. June 30, December 31, (In millions) 2020 2019 REGULATORY ASSETS Current: SPP cost tracker under recovery (A) $ 5.8 $ — Generation Capacity Replacement rider under recovery (A) 4.1 3.7 Fuel clause under recoveries — 39.5 Other (A) 6.8 5.5 Total current regulatory assets $ 16.7 $ 48.7 Non-current: Benefit obligations regulatory asset $ 163.0 $ 167.2 Deferred storm expenses 63.8 65.5 Sooner Dry Scrubbers 20.2 20.6 Smart Grid 14.8 18.4 Unamortized loss on reacquired debt 10.2 10.6 Arkansas deferred pension expenses 7.6 8.0 COVID-19 deferred expenses 3.8 — Pension tracker — 2.3 Other 16.0 13.4 Total non-current regulatory assets $ 299.4 $ 306.0 REGULATORY LIABILITIES Current: Fuel clause over recoveries $ 37.2 $ 4.8 Reserve for tax refund and interim surcharge (B) 5.9 12.7 Oklahoma demand program rider over recovery (B) 3.6 2.0 SPP cost tracker over recovery (B) — 2.6 Other (B) 5.7 6.9 Total current regulatory liabilities $ 52.4 $ 29.0 Non-current: Income taxes refundable to customers, net $ 882.6 $ 899.2 Accrued removal obligations, net 317.9 318.5 Pension tracker 0.4 — Other 5.3 5.8 Total non-current regulatory liabilities $ 1,206.2 $ 1,223.5 (A) Included in Other Current Assets in the Condensed Consolidated Balance Sheets. (B) Included in Other Current Liabilities in the Condensed Consolidated Balance Sheets. 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. For additional information about these orders, see Note 14 and "Item 2. Management's Discussion and Analysis - Recent Developments." Management continuously monitors the future recoverability of regulatory assets. When in management's judgment future recovery becomes impaired, the amount of the regulatory asset is adjusted, as appropriate. If OG&E were required to discontinue the application of accounting principles for certain types of rate-regulated activities for some or all of its operations, it could result in writing off the related regulatory assets or liabilities, which could have significant financial effects.
Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block]	Organization The Company is a holding company with investments in energy and energy services providers offering physical delivery and related services for both electricity and natural gas primarily in the south-central U.S. The Company conducts these activities through two business segments: (i) electric utility and (ii) natural gas midstream operations. The accounts of the Company and its wholly-owned subsidiaries are included in the Condensed Consolidated Financial Statements. All intercompany transactions and balances are eliminated in consolidation. The Company 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. The electric utility segment generates, transmits, distributes and sells electric energy in Oklahoma and western Arkansas. Its operations are conducted through OG&E and 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 the Company. 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. The natural gas midstream operations segment represents the Company's investment in Enable through wholly-owned subsidiaries and ultimately OGE Holdings. Enable was formed in 2013, and its general partner is equally controlled by the Company and CenterPoint, who each have 50 percent management ownership. Based on the 50/50 management ownership, with neither company having control, the Company accounts for its interest in Enable using the equity method of accounting. Enable is primarily engaged in the business of gathering, processing, transporting and storing natural gas. Enable's natural gas gathering and processing assets are strategically located in four states and serve natural gas production in the Anadarko, Arkoma and Ark-La-Tex Basins. Enable also owns crude oil gathering assets in the Anadarko and Williston Basins. Enable has intrastate natural gas transportation and storage assets that are located in Oklahoma as well as interstate assets that extend from western Oklahoma and the Texas Panhandle to Louisiana, from Louisiana to Illinois and from Louisiana to Alabama.
Basis of Accounting [Text Block]	Basis of Presentation The Condensed Consolidated Financial Statements included herein have been prepared by the Company, without audit, pursuant to the rules and regulations of the Securities and Exchange Commission. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations; however, the Company believes that the disclosures are adequate to prevent the information presented from being misleading. In the opinion of management, all adjustments necessary to fairly present the consolidated financial position of the Company at June 30, 2020 and December 31, 2019, the consolidated results of its operations for the three and six months ended June 30, 2020 and 2019 and its consolidated cash flows for the six months ended June 30, 2020 and 2019 have been included and are of a normal, recurring nature except as otherwise disclosed. Management also has evaluated the impact of events occurring after June 30, 2020 up to the date of issuance of these Condensed Consolidated Financial Statements, and these statements contain all necessary adjustments and disclosures resulting from that evaluation. Due to seasonal fluctuations and other factors, the Company's operating results for the three and six months ended June 30, 2020 are not necessarily indicative of the results that may be expected for the year ending December 31, 2020 or for any future period. The Condensed Consolidated Financial Statements and Notes thereto should be read in conjunction with the audited Consolidated Financial Statements and Notes thereto included in the Company's 2019 Form 10-K .
Schedule of Regulatory Assets and Liabilities	Management continuously monitors the future recoverability of regulatory assets. When in management's judgment future recovery becomes impaired, the amount of the regulatory asset is adjusted, as appropriate. If OG&E were required to discontinue the application of accounting principles for certain types of rate-regulated activities for some or all of its operations, it could result in writing off the related regulatory assets or liabilities, which could have significant financial effects.
Comprehensive Income (Loss) Note [Text Block]	Accumulated Other Comprehensive Income (Loss) The following tables summarize changes in the components of accumulated other comprehensive income (loss) attributable to the Company during the six months ended June 30, 2020 and 2019. All amounts below are presented net of tax. (In millions) Pension Plan and Restoration of Retirement Income Plan Postretirement Benefit Plans Other Comprehensive Loss from Unconsolidated Affiliates Total Balance at December 31, 2019 $ (35.1) $ 7.8 $ (0.6) $ (27.9) Other comprehensive income (loss) before reclassifications — — (1.3) (1.3) Amounts reclassified from accumulated other comprehensive income (loss) 2.0 (0.9) — 1.1 Settlement cost 0.2 — — 0.2 Balance at June 30, 2020 $ (32.9) $ 6.9 $ (1.9) $ (27.9) (In millions) Pension Plan and Restoration of Retirement Income Plan Postretirement Benefit Plans Total Balance at December 31, 2018 $ (38.8) $ 9.9 $ (28.9) Amounts reclassified from accumulated other comprehensive income (loss) 1.7 (1.0) 0.7 Settlement cost 7.1 — 7.1 Balance at June 30, 2019 $ (30.0) $ 8.9 $ (21.1) The following table summarizes significant amounts reclassified out of accumulated other comprehensive income (loss) by the respective line items in net income (loss) during the three and six months ended June 30, 2020 and 2019. Details about Accumulated Other Comprehensive Income (Loss) Components Amount Reclassified from Accumulated Other Comprehensive Income (Loss) Affected Line Item in the Consolidated Statements of Income Three Months Ended Six Months Ended June 30, June 30, (In millions) 2020 2019 2020 2019 Amortization of Pension Plan and Restoration of Retirement Income Plan items: Actuarial losses $ (1.5) $ (1.3) $ (2.6) $ (2.2) (A) Settlement cost (0.3) (0.6) (0.3) (9.4) (A) (1.8) (1.9) (2.9) (11.6) Income (Loss) Before Taxes (0.4) (0.4) (0.7) (2.8) Income Tax Expense (Benefit) $ (1.4) $ (1.5) $ (2.2) $ (8.8) Net Income (Loss) Amortization of postretirement benefit plans items: Prior service credit $ 0.5 $ 0.5 $ 1.1 $ 1.1 (A) Actuarial gains 0.1 0.1 0.1 0.1 (A) 0.6 0.6 1.2 1.2 Income (Loss) Before Taxes 0.1 0.1 0.3 0.2 Income Tax Expense (Benefit) $ 0.5 $ 0.5 $ 0.9 $ 1.0 Net Income (Loss) Total reclassifications for the period, net of tax $ (0.9) $ (1.0) $ (1.3) $ (7.8) Net Income (Loss) (A) These accumulated other comprehensive income (loss) components are included in the computation of net periodic benefit cost (see Note 11 for additional information).
Allowance for Credit Losses	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 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. 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 Condensed Consolidated Balance Sheets and is included in the Other Operation and Maintenance in the Condensed Consolidated Statements of Income. 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 may be 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.

Accounting Pronouncements

Accounting Pronouncements	6 Months Ended
	Jun. 30, 2020
Accounting Standards Update and Change in Accounting Principle [Abstract]
New Accounting Pronouncements and Changes in Accounting Principles [Text Block]	Accounting Pronouncements Recently Adopted Accounting Standards The following table provides an overview of recently adopted accounting pronouncements and their impacts on the Company. ASU Number and Name Description Date of Adoption Financial Statements and Disclosures Impact ASU 2016-13, "Financial Instruments - Credit Losses: Measurement of Credit Losses on Financial Information" This standard requires entities to measure all expected credit losses of financial assets held at a reporting date based on historical experience, current conditions and reasonable and supportable forecasts in order to record credit losses in a more timely manner. January 1, 2020 Utilizing a modified-retrospective approach, the Company determined its only financial instrument requiring measurement under ASU 2016-13 is trade receivables. The Company considers both future economic conditions and historical data to measure the reserve for trade receivables under this standard and determined no adjustments to its reserve were necessary upon adoption. ASU 2018-15, "Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40)" The standard aligns requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. January 1, 2020 The new standard did not have a material effect on the Company's financial statements upon adoption. Prospectively, the Company records applicable capitalized implementation costs in Other Current Assets and related amortization expense in Other Operation and Maintenance. ASU 2018-13, "Fair Value Measurement (Topic 820): Disclosure Framework" The standard removes, adds or modifies disclosure requirements that impact all levels of the fair value hierarchy, as well as investments measured using the net asset value practical expedient. January 1, 2020 The Company applied the guidance on a retrospective or prospective basis, depending on the requirement, and did not experience a significant impact on its financial statement disclosures. ASU 2018-14, "Compensation - Retirement Benefits - Defined Benefit Plans - General (Subtopic 715-20)" The standard removes, adds or clarifies disclosure requirements for employers that sponsor defined benefit pension or other postretirement plans. January 1, 2020 The Company applied the guidance on a retrospective basis and did not experience a significant impact on its financial statement disclosures. ASU 2020-04, "Reference Rate Reform (Topic 848)" This standard provides optional expedients and exceptions, if certain criteria are met, for applying GAAP to contracts, hedging relationships and other transactions that reference LIBOR or another reference rate expected to be discontinued because of reference rate reform. January 1, 2020 The guidance did not have a material impact upon adoption, nor does the Company expect a material impact in the future, on its consolidated financial statements.

Revenue from Contracts with Cus

Revenue from Contracts with Customers (Notes)	6 Months Ended
	Jun. 30, 2020
Revenue from Contract with Customer [Abstract]
Revenue from Contract with Customer [Text Block]	Revenue Recognition The following table disaggregates the Company's revenues from contracts with customers by customer classification. The Company's operating revenues disaggregated by customer classification can be found in "OG&E (Electric Utility) Results of Operations" within "Item 2. Management's Discussion and Analysis of Financial Condition and Results of Operations." Three Months Ended June 30, Six Months Ended June 30, (In millions) 2020 2019 2020 2019 Residential $ 202.8 $ 182.3 $ 369.7 $ 373.5 Commercial 113.0 115.4 204.3 210.8 Industrial 44.7 52.9 86.2 105.2 Oilfield 38.4 48.9 76.6 98.3 Public authorities and street light 40.6 44.4 75.3 84.5 System sales revenues 439.5 443.9 812.1 872.3 Provision for rate refund (1.0) (0.5) (1.6) (0.6) Integrated market 8.5 10.3 15.7 17.0 Transmission 39.8 39.8 74.0 75.9 Other 5.2 7.6 12.2 13.9 Revenues from contracts with customers $ 492.0 $ 501.1 $ 912.4 $ 978.5

Investment in Unconsolidated Af

Investment in Unconsolidated Affiliates	6 Months Ended
	Jun. 30, 2020
Related Party Transactions [Abstract]
Equity Method Investments and Joint Ventures Disclosure [Text Block]	Investment in Unconsolidated Affiliates The Company's investment in Enable is considered to be a variable interest entity because the owners of the equity at risk in this entity have disproportionate voting rights in relation to their obligations to absorb the entity's expected losses or to receive its expected residual returns. However, the Company is not considered the primary beneficiary of Enable since it does not have the power to direct the activities of Enable that are considered most significant to the economic performance of Enable; therefore, the Company accounts for its investment in Enable using the equity method of accounting. Under the equity method, the investment will be adjusted each period for contributions made, distributions received and the Company's share of the investee's comprehensive income as adjusted for basis differences. The Company's maximum exposure to loss related to Enable is limited to the Company's equity investment in Enable at June 30, 2020 as presented in Note 12. The Company evaluates its equity method investments for impairment when events or changes in circumstances indicate there is a loss in value of the investment that is other than a temporary decline. When indicators exist, the fair value is estimated and compared to the investment carrying value, and if any impairment is judgmentally determined to be other than temporary, the carrying value of the investment is written down to fair value. The Company determined, effective March 31, 2020, that an other than temporary decline in the value of the Company's investment in Enable had occurred. Further information detailing the results of the Company's impairment analysis and fair value measurement can be found in Notes 4 and 5. The Company considers distributions received from Enable, which do 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 Condensed Consolidated Statements of Cash Flows. The Company considers 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 Condensed Consolidated Statements of Cash Flows. At June 30, 2020, the Company owned 111.0 million common units, or 25.5 percent, of Enable's outstanding common units. On June 30, 2020, Enable's common unit price closed at $4.68. The Company recorded equity in earnings of unconsolidated affiliates of $26.9 million for the three months ended June 30, 2020 and equity in losses of unconsolidated affiliates of $719.6 million for the six months ended June 30, 2020, compared to equity in earnings of unconsolidated affiliates of $35.8 million and $66.5 million for the three and six months ended June 30, 2019, respectively. Equity in earnings (losses) of unconsolidated affiliates includes the Company's share of Enable's earnings adjusted for the amortization of the basis difference of the Company's original investment in Enogex LLC and its underlying equity in the net assets of Enable, as well as any impairment the Company records on its investment in Enable. Equity in earnings (losses) of unconsolidated affiliates is also adjusted for the elimination of the Enogex Holdings fair value adjustments. These amortizations may also include gain or loss on dilution, net of proportional basis difference recognition. For more information concerning the formation of Enable and the Company's accounting for its investment in Enable, see Note 5 within "Item 8. Financial Statements and Supplementary Data" in the Company's 2019 Form 10-K . The Company evaluates its equity method investment for impairment when factors indicate that a decline in the value of its investment has occurred and the carrying amount of its investment may not be recoverable. An impairment loss, based on the excess of the carrying value over estimated fair value of the investment, is recognized in earnings when an impairment is deemed to be other than temporary. Considerable judgment is used in determining if an impairment loss is other than temporary and the amount of any impairment. Effective March 31, 2020, the Company 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 the recent rapid deterioration, as well as the near term future outlook, of the midstream oil and gas industry. Accordingly, the Company recorded a $780.0 million impairment on its investment in Enable in March 2020, which is included in Equity in Earnings (Losses) of Unconsolidated Affiliates in the Company's 2020 Condensed Consolidated Income Statement. Further information concerning the fair value method used to measure the impairment on the Company's investment in Enable can be found in Note 5. Summarized unaudited financial information for 100 percent of Enable is presented below at June 30, 2020 and December 31, 2019 and for the three and six months ended June 30, 2020 and 2019. June 30, December 31, Balance Sheet 2020 2019 (In millions) Current assets $ 374 $ 389 Non-current assets $ 11,687 $ 11,877 Current liabilities $ 290 $ 780 Non-current liabilities $ 4,454 $ 4,077 Three Months Ended Six Months Ended June 30, June 30, Income Statement 2020 2019 2020 2019 (In millions) Total revenues $ 515 $ 735 $ 1,163 $ 1,530 Cost of natural gas and NGLs $ 177 $ 317 $ 403 $ 695 Operating income $ 80 $ 167 $ 226 $ 332 Net income $ 35 $ 115 $ 138 $ 228 The following table reconciles the Company's equity in earnings (losses) of unconsolidated affiliates for the three and six months ended June 30, 2020 and 2019. Three Months Ended Six Months Ended June 30, June 30, (In millions) 2020 2019 2020 2019 Enable net income $ 35.0 $ 114.8 $ 138.0 $ 228.1 OGE Energy's percent ownership at period end 25.5 % 25.5 % 25.5 % 25.5 % OGE Energy's portion of Enable net income $ 8.8 $ 29.3 $ 35.1 $ 58.2 Amortization of basis difference and dilution recognition (A) 18.1 6.5 25.3 8.3 Impairment of OGE Energy's equity method investment in Enable — — (780.0) — Equity in earnings (losses) of unconsolidated affiliates $ 26.9 $ 35.8 $ (719.6) $ 66.5 (A) Includes loss on dilution, net of proportional basis difference recognition. The following table reconciles the difference between OGE Energy's investment in Enable and its underlying equity in the net assets of Enable (basis difference) from December 31, 2019 to June 30, 2020. The basis difference is being amortized over approximately 30 years. (In millions) Basis difference at December 31, 2019 $ 652.5 Amortization of basis difference (A) (26.3) Impairment of OGE Energy's equity method investment in Enable 780.0 Basis difference at June 30, 2020 $ 1,406.2 (A) Includes proportional basis difference recognition due to dilution. On April 1, 2020, Enable announced a 50 percent reduction to its quarterly distribution in order to strengthen its balance sheet and increase its annualized retained cash flow. See "Item 2. Management's Discussion and Analysis - Recent Developments" for further discussion of the Company's response. On August 4, 2020, Enable announced a quarterly dividend distribution of $0.16525 per unit on its outstanding common units, which is unchanged from the previous quarter and a decrease from the beginning of the year dividend distribution of $0.33050 per unit. If cash distributions to Enable's unitholders exceed $0.330625 per unit in any quarter, the general partner will receive increasing percentages, up to 50 percent, of the cash Enable distributes in excess of that amount. The Company is entitled to 60 percent of those "incentive distributions." In certain circumstances, the general partner has the right to reset the minimum quarterly distribution and the target distribution levels at which the incentive distributions receive increasing percentages to higher levels based on Enable's cash distributions at the time of the exercise of this reset election. Distributions received from Enable were $18.3 million and $35.3 million during the three months ended June 30, 2020 and 2019, respectively, and $55.0 million and $70.6 million during the six months ended June 30, 2020 and 2019, respectively. Related Party Transactions The Company charges operating costs to OG&E and Enable based on several factors, and 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. The Company and Enable The Company and Enable are currently parties to several agreements whereby the Company provides specified support services to Enable, such as certain information technology, payroll and benefits administration. Under these agreements, the Company charged operating costs to Enable of $0.1 million during both the three months ended June 30, 2020 and 2019 and $0.2 million during both the six months ended June 30, 2020 and 2019. Pursuant to a seconding agreement, the Company provides seconded employees to Enable to support Enable's operations. As of June 30, 2020, 80 employees that participate in the Company's defined benefit and retirement plans are seconded to Enable. The Company billed Enable for reimbursement of $3.8 million and $4.0 million during the three months ended June 30, 2020 and 2019, respectively, and $10.1 million and $16.4 million during the six months ended June 30, 2020 and 2019, respectively, under the seconding agreement for employment costs. If the seconding agreement was terminated, and those employees were no longer employed by the Company, and lump sum payments were made to those employees, the Company would recognize a settlement or curtailment of the pension/retiree health care charges, which would increase expense at the Company by $16.5 million. Settlement and curtailment charges associated with the Enable seconded employees are not reimbursable to the Company by Enable. The seconding agreement can be terminated by mutual agreement of the Company and Enable or solely by the Company upon 120 days' notice. The Company had accounts receivable from Enable for amounts billed for support services, including the cost of seconded employees, of $2.2 million as of June 30, 2020 and $0.8 million as of December 31, 2019, which are included in Accounts Receivable in the Company's Condensed Consolidated Balance Sheets. OG&E and Enable Enable provides gas transportation services to OG&E pursuant to an agreement that grants 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 purchases gas from Enable when Enable's deliveries exceed OG&E's pipeline receipts. Enable purchases gas from OG&E when OG&E's pipeline receipts exceed Enable's deliveries. The following table summarizes related party transactions between OG&E and Enable during the three and six months ended June 30, 2020 and 2019. Three Months Ended Six Months Ended June 30, June 30, (In millions) 2020 2019 2020 2019 Operating revenues: Electricity to power electric compression assets $ 3.5 $ 3.8 $ 7.2 $ 7.6 Cost of sales: Natural gas transportation services $ 9.4 $ 9.3 $ 14.1 $ 24.1 Natural gas purchases (sales) $ (1.7) $ (3.3) $ (1.0) $ (4.3)

Fair Value Measurements

Fair Value Measurements	6 Months Ended
	Jun. 30, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The classification of the Company's 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). The Company had no financial instruments measured at fair value on a recurring basis at June 30, 2020 and December 31, 2019. The following table summarizes the carrying amount and fair value of the Company's financial instruments at June 30, 2020 and December 31, 2019. June 30, December 31, 2020 2019 (In millions) Carrying Amount Fair Carrying Amount Fair Classification Long-term Debt (including Long-term Debt due within one year): OG&E Senior Notes $ 3,348.5 $ 4,024.7 $ 3,050.3 $ 3,500.4 Level 2 OG&E Industrial Authority Bonds $ 135.4 $ 135.4 $ 135.4 $ 135.4 Level 2 Tinker Debt $ 9.5 $ 10.7 $ 9.5 $ 10.0 Level 3 Nonrecurring Fair Value Measurements As further discussed in Note 4, the Company 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. The Company concluded that this valuation method resulted in a Level 3 nonrecurring fair value measurement.

Stock-Based Compensation

Stock-Based Compensation	6 Months Ended
	Jun. 30, 2020
Share-based Payment Arrangement [Abstract]
Share-based Payment Arrangement [Text Block]	Stock-Based Compensation The following table summarizes the Company's pre-tax compensation expense and related income tax benefit during the three and six months ended June 30, 2020 and 2019 related to the Company's performance units and restricted stock units. Three Months Ended June 30, Six Months Ended June 30, (In millions) 2020 2019 2020 2019 Performance units: Total shareholder return $ 2.0 $ 2.3 $ 3.7 $ 4.5 Earnings per share 0.1 0.4 0.3 0.9 Total performance units 2.1 2.7 4.0 5.4 Restricted stock units 0.2 0.2 0.3 0.5 Total compensation expense $ 2.3 $ 2.9 $ 4.3 $ 5.9 Income tax benefit $ 0.6 $ 0.7 $ 1.1 $ 1.5

Income Taxes

Income Taxes	6 Months Ended
	Jun. 30, 2020
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes The Company files consolidated income tax returns in the U.S. federal jurisdiction and various state jurisdictions. With few exceptions, the Company is no longer subject to U.S. federal tax or state and local examinations by tax authorities for years prior to 2016. Income taxes are generally allocated to each company in the affiliated group 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 the Company's effective tax rate.

Common Equity

Common Equity	6 Months Ended
	Jun. 30, 2020
Common Equity [Text Block]	Common Equity Automatic Dividend Reinvestment and Stock Purchase Plan The Company issued no shares of common stock under its Automatic Dividend Reinvestment and Stock Purchase Plan during the three and six months ended June 30, 2020. Earnings (Loss) Per Share Basic earnings (loss) per share is calculated by dividing net income (loss) attributable to the Company by the weighted-average number of the Company'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 the Company consist of performance units and restricted stock units. The following table calculates basic and diluted earnings (loss) per share for the Company. Three Months Ended June 30, Six Months Ended June 30, (In millions except per share data) 2020 2019 2020 2019 Net income (loss) $ 85.9 $ 100.2 $ (405.9) $ 147.3 Average common shares outstanding: Basic average common shares outstanding 200.2 200.2 200.2 200.1 Effect of dilutive securities: Contingently issuable shares (performance and restricted stock units) 0.3 0.4 — 0.4 Diluted average common shares outstanding 200.5 200.6 200.2 200.5 Basic earnings (loss) per average common share $ 0.43 $ 0.50 $ (2.03) $ 0.74 Diluted earnings (loss) per average common share $ 0.43 $ 0.50 $ (2.03) $ 0.73 Anti-dilutive shares excluded from earnings per share calculation — — — —

Long-Term Debt

Long-Term Debt	6 Months Ended
	Jun. 30, 2020
Long-term Debt, Unclassified [Abstract]
Long-Term Debt	Long-Term Debt At June 30, 2020, the Company was in compliance with all of its debt agreements. 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 bonds, which can be tendered at the option of the holder during the next 12 months, are included in the following table. Series Date Due Amount (In millions) 0.35% - 2.20% Garfield Industrial Authority, January 1, 2025 $ 47.0 0.37% - 1.50% Muskogee Industrial Authority, January 1, 2025 32.4 0.35% - 2.20% 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 Company's Condensed Consolidated Balance Sheets. OG&E believes that it has sufficient liquidity to meet these obligations. Issuance of Long-Term Debt In April 2020, OG&E issued $300.0 million of 3.25 percent senior notes due April 1, 2030. The proceeds from the issuance were added to OG&E's general funds to be used for general corporate purposes, including to fund ongoing capital expenditures and working capital.

Short-Term Debt and Credit Faci

Short-Term Debt and Credit Facilities	6 Months Ended
	Jun. 30, 2020
Short-term Debt [Abstract]
Short-Term Debt and Credit Facilities	Short-Term Debt and Credit Facilities The Company holds short-term debt through revolving credit facilities and term credit agreements maturing in one year or less. As of June 30, 2020, the Company had $75.0 million of short-term debt as compared to $112.0 million of short-term debt at December 31, 2019. The Company borrows on a short-term basis, as necessary, by the issuance of commercial paper and borrowings under its revolving credit agreements and term credit agreement. In April 2020, the Company entered into a $75.0 million floating rate unsecured one-year term credit agreement and borrowed the full $75.0 million, in order to preserve financial flexibility in response to COVID-19. Advances under this agreement were used to refinance existing indebtedness and for working capital and general corporate purposes of the Company. The term credit agreement, under certain circumstances, may be increased to a maximum commitment limit of $100.0 million and contains substantially the same covenants as the Company's existing $450.0 million revolving credit agreement. The term credit agreement is scheduled to terminate on April 7, 2021. At June 30, 2020, the weighted-average interest rate for the amount drawn on the term loan was 1.25 percent. The following table provides information regarding the Company's revolving credit agreements at June 30, 2020. Aggregate Amount Weighted-Average Entity Commitment Outstanding (A) Interest Rate Expiration (In millions) OGE Energy (B) $ 450.0 $ — — % (D) March 8, 2023 OG&E (C) 450.0 0.3 1.15 % (D) March 8, 2023 Total $ 900.0 $ 0.3 1.15 % (A) Includes direct borrowings under the revolving credit agreements, commercial paper borrowings and letters of credit at June 30, 2020. (B) This bank facility is available to back up the Company'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) Represents the weighted-average interest rate for the outstanding borrowings under the revolving credit agreements, commercial paper borrowings and letters of credit. The Company's 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 Company's 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 Company's short-term borrowings, but a reduction in the Company's 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 Company to post collateral or letters of credit.

Retirement Plans and Postretire

Retirement Plans and Postretirement Benefit Plans	6 Months Ended
	Jun. 30, 2020
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]
Pension and Other Postretirement Benefits Disclosure [Text Block]	Retirement Plans and Postretirement Benefit Plans Net Periodic Benefit Cost The following table presents the net periodic benefit cost components, before consideration of capitalized amounts, of the Company's Pension Plan, Restoration of Retirement Income Plan and postretirement benefit plans that are included in the Condensed Consolidated Financial Statements. Service cost is presented within Other Operation and Maintenance, and the remaining net periodic benefit cost components as listed in the table below are presented within Other Net Periodic Benefit Expense in the Company's Condensed Consolidated 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 Company's Condensed Consolidated Statements of Income. Pension Plan Restoration of Retirement Three Months Ended Six Months Ended Three Months Ended Six Months Ended June 30, June 30, June 30, June 30, (In millions) 2020 2019 2020 2019 2020 2019 2020 2019 Service cost $ 2.8 $ 2.8 $ 6.5 $ 6.3 $ 0.2 $ 0.1 $ 0.4 $ 0.2 Interest cost 4.6 5.2 9.2 10.9 — 0.1 0.1 0.2 Expected return on plan assets (9.2) (8.9) (18.6) (17.6) — — — — Amortization of net loss 4.6 4.8 8.4 8.6 0.2 0.1 0.3 0.2 Settlement cost — 0.9 — 20.6 0.3 — 0.3 — Total net periodic benefit cost 2.8 4.8 5.5 28.8 0.7 0.3 1.1 0.6 Less: Amount paid by unconsolidated affiliates 0.6 0.8 1.1 1.7 — — — — Net periodic benefit cost $ 2.2 $ 4.0 $ 4.4 $ 27.1 $ 0.7 $ 0.3 $ 1.1 $ 0.6 (A) In addition to the net periodic benefit cost amounts recognized, as presented in the table above, for the Pension and Restoration of Retirement Income Plans for the three and six months ended June 30, 2020 and 2019, the Company recognized the following: Three Months Ended June 30, Six Months Ended June 30, (In millions) 2020 2019 2020 2019 Increase (decrease) of pension expense to maintain allowed recoverable amount in Oklahoma jurisdiction (A) $ 1.6 $ (0.7) $ 3.3 $ (1.7) Deferral of pension expense related to pension settlement charges: Oklahoma jurisdiction (A) $ 0.3 $ 0.5 $ 0.3 $ 11.7 Arkansas jurisdiction (A) $ — $ 0.1 $ — $ 1.1 (A) Included in the pension regulatory asset or liability in each jurisdiction, as indicated in the regulatory assets and liabilities table in Note 1. Postretirement Benefit Plans Three Months Ended Six Months Ended June 30, June 30, (In millions) 2020 2019 2020 2019 Service cost $ — $ — $ 0.1 $ 0.1 Interest cost 1.0 1.4 2.1 2.8 Expected return on plan assets (0.4) (0.4) (0.9) (0.9) Amortization of net loss 0.4 0.4 1.0 1.0 Amortization of unrecognized prior service cost (A) (2.1) (2.1) (4.2) (4.2) Total net periodic benefit cost (1.1) (0.7) (1.9) (1.2) Less: Amount paid by unconsolidated affiliates (0.2) (0.1) (0.4) (0.3) Net periodic benefit cost $ (0.9) $ (0.6) $ (1.5) $ (0.9) (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. In addition to the net periodic benefit income amounts recognized, as presented in the table above, for the postretirement benefit plans for the three and six months ended June 30, 2020 and 2019, the Company recognized the following: Three Months Ended June 30, Six Months Ended June 30, (In millions) 2020 2019 2020 2019 Increase of postretirement expense to maintain allowed recoverable amount in Oklahoma jurisdiction (A) $ 0.6 $ 0.5 $ 0.8 $ 0.8 (A) Included in the Pension tracker, as presented in the regulatory assets and liabilities table in Note 1. Three Months Ended Six Months Ended June 30, June 30, (In millions) 2020 2019 2020 2019 Capitalized portion of net periodic pension benefit cost $ 0.8 $ 0.8 $ 1.8 $ 1.8 Capitalized portion of net periodic postretirement benefit cost $ 0.1 $ — $ 0.1 $ 0.1

Report of Business Segments

Report of Business Segments	6 Months Ended
	Jun. 30, 2020
Segment Reporting [Abstract]
Report of Business Segments	Report of Business Segments The Company 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) the natural gas midstream operations segment. Intersegment revenues are recorded at prices comparable to those of unaffiliated customers and are affected by regulatory considerations. The following tables summarize the results of the Company's business segments during the three and six months ended June 30, 2020 and 2019. Three Months Ended June 30, 2020 Electric Utility Natural Gas Midstream Operations Other Eliminations Total (In millions) Operating revenues $ 503.5 $ — $ — $ — $ 503.5 Cost of sales 137.4 — — — 137.4 Other operation and maintenance 117.7 0.3 (0.5) — 117.5 Depreciation and amortization 97.3 — — — 97.3 Taxes other than income 25.0 0.1 0.8 — 25.9 Operating income (loss) 126.1 (0.4) (0.3) — 125.4 Equity in earnings of unconsolidated affiliates — 26.9 — — 26.9 Other income 0.5 — 1.7 (0.2) 2.0 Interest expense 39.3 — 1.7 (0.2) 40.8 Income tax expense 8.4 7.5 11.7 — 27.6 Net income (loss) $ 78.9 $ 19.0 $ (12.0) $ — $ 85.9 Investment in unconsolidated affiliates $ — $ 356.4 $ 20.1 $ — $ 376.5 Total assets $ 10,367.6 $ 360.2 $ 109.1 $ (397.8) $ 10,439.1 Three Months Ended June 30, 2019 Electric Utility Natural Gas Midstream Operations Other Eliminations Total (In millions) Operating revenues $ 513.7 $ — $ — $ — $ 513.7 Cost of sales 178.7 — — — 178.7 Other operation and maintenance 120.0 0.3 (0.5) — 119.8 Depreciation and amortization 84.3 — — — 84.3 Taxes other than income 20.1 0.1 0.7 — 20.9 Operating income (loss) 110.6 (0.4) (0.2) — 110.0 Equity in earnings of unconsolidated affiliates — 35.8 — — 35.8 Other income (expense) 1.5 (0.4) 1.0 (0.6) 1.5 Interest expense 33.3 — 3.2 (0.6) 35.9 Income tax expense (benefit) 4.3 8.1 (1.2) — 11.2 Net income (loss) $ 74.5 $ 26.9 $ (1.2) $ — $ 100.2 Investment in unconsolidated affiliates $ — $ 1,157.2 $ 14.1 $ — $ 1,171.3 Total assets $ 9,733.8 $ 1,160.0 $ 104.5 $ (112.1) $ 10,886.2 Six Months Ended June 30, 2020 Electric Utility Natural Gas Midstream Operations Other Eliminations Total (In millions) Operating revenues $ 934.8 $ — $ — $ — $ 934.8 Cost of sales 272.4 — — — 272.4 Other operation and maintenance 238.7 0.9 (2.1) — 237.5 Depreciation and amortization 191.7 — — — 191.7 Taxes other than income 48.9 0.2 2.4 — 51.5 Operating income (loss) 183.1 (1.1) (0.3) — 181.7 Equity in earnings (losses) of unconsolidated affiliates (A) — (719.6) — — (719.6) Other income 2.3 — 3.0 (1.2) 4.1 Interest expense 76.2 — 4.1 (1.2) 79.1 Income tax expense (benefit) 10.4 (171.7) (45.7) — (207.0) Net income (loss) $ 98.8 $ (549.0) $ 44.3 $ — $ (405.9) Investment in unconsolidated affiliates $ — $ 356.4 $ 20.1 $ — $ 376.5 Total assets $ 10,367.6 $ 360.2 $ 109.1 $ (397.8) $ 10,439.1 (A) In March 2020, the Company recorded a $780.0 million impairment on its investment in Enable, as further discussed in Notes 4 and 5. Six Months Ended June 30, 2019 Electric Utility Natural Gas Midstream Operations Other Eliminations Total (In millions) Operating revenues $ 1,003.7 $ — $ — $ — $ 1,003.7 Cost of sales 391.3 — — — 391.3 Other operation and maintenance 240.3 0.7 (2.2) — 238.8 Depreciation and amortization 166.7 — — — 166.7 Taxes other than income 44.5 0.3 2.4 — 47.2 Operating income (loss) 160.9 (1.0) (0.2) — 159.7 Equity in earnings of unconsolidated affiliates — 66.5 — — 66.5 Other income (expense) 4.1 (7.8) 1.7 (1.0) (3.0) Interest expense 65.7 — 5.8 (1.0) 70.5 Income tax expense (benefit) 5.2 9.5 (9.3) — 5.4 Net income $ 94.1 $ 48.2 $ 5.0 $ — $ 147.3 Investment in unconsolidated affiliates $ — $ 1,157.2 $ 14.1 $ — $ 1,171.3 Total assets $ 9,733.8 $ 1,160.0 $ 104.5 $ (112.1) $ 10,886.2

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2020
Long-term Purchase Commitment [Line Items]
Commitments and Contingencies Disclosure [Text Block]	Commitments and Contingencies Except as set forth below, in Note 14 and under "Environmental Laws and Regulations" in Item 2 of Part I and in Item 1 of Part II of this Form 10-Q, the circumstances set forth in Notes 15 and 16 to the Consolidated Financial Statements included in the Company's 2019 Form 10-K appropriately represent, in all material respects, the current status of the Company's material commitments and contingent liabilities. Environmental Laws and Regulations The activities of OG&E 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 OG&E's 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 its 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. Other

Regulated Operations

Regulated Operations	6 Months Ended
	Jun. 30, 2020
Regulated Operations [Abstract]
Rate Matters and Regulation	Rate Matters and Regulation Except as set forth below, the circumstances set forth in Note 16 to the Consolidated Financial Statements included in the Company's 2019 Form 10-K appropriately represent, in all material respects, the current status of the Company's regulatory matters. Completed Regulatory Matters APSC Proceedings Arkansas 2019 Formula Rate Plan Filing OG&E filed its second evaluation report under its Formula Rate Plan in October 2019. On January 29, 2020, OG&E, the General Staff of the APSC and the Office of the Arkansas Attorney General filed a settlement agreement requesting the APSC approve a $5.2 million revenue increase, with rates effective April 1, 2020. The settling parties agreed that the Series I grid modernization projects are prudent in both action and cost and that the Series II grid modernization projects are prudent in action only and the determination of prudence of costs will be reserved until the actual historical costs are reviewed. The settling parties also agreed that OG&E will no longer use projections for the remaining initial term or extension of its current Formula Rate Plan and that all costs will be included for recovery for the first time in the historical year. On February 28, 2020, the APSC approved the settlement agreement. Order Regarding COVID-19 On April 10, 2020, the APSC issued Order No. 1 related to COVID-19 and the provision of safe, adequate and reliable utility service at just and reasonable rates. Among other things, the APSC ordered the suspension of customer disconnects for non-payment during the pendency of the Arkansas Governor's emergency declaration or until the directive is rescinded by the APSC, neither of which have occurred yet. The order encourages companies to provide reasonable payment arrangements once the suspension is lifted. The APSC also authorized utilities to establish regulatory assets to record costs resulting from the suspension of disconnections. These regulatory assets will be reviewed in future proceedings for reasonableness. The APSC ordered the General Staff of the APSC to consult with utilities to create a quarterly report to be used to report the costs incurred and saved that have been booked to the regulatory asset. OG&E is monitoring the regulatory activity regarding COVID-19 at the APSC and will consider the request for additional regulatory action by the APSC as needed. On May 1, 2020, OG&E filed a Request for Additional Actions and Tariff Deviation seeking relief from the Arkansas General Service Rules and OG&E's Terms and Conditions under the tariff, in order to allow for: more flexible deferred payment agreements for all customer classes, suspension of increased deposits due to non-payment and suspension of the removal of customers from certain billing and extended due date plans for late payments. In addition, OG&E requested that incremental expenses, such as additional personal protective equipment, increased sanitation efforts at facilities, implementing health-screening processes and securing temporary facilities for potential sequestration of critical operation personnel, be tracked in a regulatory asset. OG&E noted that all possible cost categories are not known currently and reserved the right to file subsequent requests as needed. On May 27, 2020, the APSC issued an order approving OG&E's request to deviate from the specified terms in the Arkansas General Service Rules and OG&E's Terms and Conditions to allow deferred payment arrangements to be offered to all customer classes and have more flexible payment arrangements. OG&E is authorized to record the expenses requested in its regulatory asset to defer and seek future recovery. The APSC found that because each utility has different cost recovery mechanisms and the magnitude of the utilities' expenses are unknown at this time, the APSC finds that it is premature to decide the exact recovery mechanism for any utility for COVID-19 related costs. OCC Proceedings OCC Public Utility Division Motion Regarding COVID-19 On April 28, 2020, the Director of the Public Utility Division filed an application requesting an order from the OCC authorizing action in response to COVID-19. The application requested that the OCC authorize the State's utilities to record as a regulatory asset increased bad debt expenses, costs associated with expanded payment plans, waived fees and incremental expenses that are directly related to the suspension of or delay in disconnection of service beginning March 15, 2020, which coincides with the issuance of the Oklahoma Governor's emergency declaration. The application also requested that the OCC allow utilities to defer additional expenses associated with ensuring the continuity of utility service, such as additional personal protective equipment, increased sanitation efforts at facilities, implementing heath-screening processes and securing temporary facilities for potential sequestration of critical operation personnel. The application asked the OCC to consider in future proceedings whether each utility's request for recovery of these regulatory assets is reasonable and necessary and to consider issues such as the incremental bad debt experienced over normal periods, the appropriate period of recovery for any approved amount of regulatory asset, any amount of carrying costs and other related matters. On May 7, 2020, the OCC ordered that each utility is authorized to record as a regulatory asset any increased bad debt expense, cost associated with expanded payment plans, waived fees and incremental expenses that are directly related to the suspension of or delay in disconnection of service beginning March 15, 2020 until September 2020, unless otherwise ordered by the OCC. The OCC will consider in future proceedings whether each utility's request for recovery of these regulatory assets is reasonable and necessary. The OCC will also consider issues such as the incremental bad debt experienced over normal periods, appropriate period of recovery for any approved amount of regulatory assets, any amounts of carrying costs thereon and other related matters. The OCC also authorized utilities to defer expenses associated with ensuring continuity of service and protecting utility personnel, customers and the general public. Pending Regulatory Matters Various proceedings pending before state or federal regulatory agencies are described below. Unless stated otherwise, OG&E cannot predict when the regulatory agency will act or what action the regulatory agency will take. OG&E's financial results are dependent in part on timely and adequate 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 - 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. On February 20, 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. On March 2, 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 appeal will likely be decided by the second quarter of 2021. The Company cannot predict the outcome of this proceeding based on currently available information, and as of June 30, 2020 and at present time, the Company has not reserved an amount for a potential refund. If the reversal of the July 2016 FERC order remains intact, 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. If refunds were required, recovery of these upgrade credits would shift to future periods. Of the $13.0 million, the Company would be impacted by $5.0 million in expense that initially benefited the Company 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. The SPP has recently proposed eliminating Attachment Z2 revenue crediting and replacing it with a different mechanism that would provide project sponsors such as OG&E the same level of recovery they would receive if payments continued under Attachment Z2. The FERC rejected that proposal to the extent it would limit recovery to the amount of the upgrade sponsor's directly assigned upgrade costs with interest, finding that providing the possibility of recovering greater than the cost of the investment could serve as an incentive for entities to build merchant transmission projects. The SPP is allowed to resubmit a proposal without this limited recovery. APSC Proceedings Environmental Compliance Plan Rider In May 2019, OG&E filed an environmental compliance plan rider in Arkansas to recover its investment for the environmentally mandated costs associated with the Sooner Dry Scrubbers project and the conversion of Muskogee Units 4 and 5 to natural gas. The filing initiated an interim surcharge, subject to refund, that began with the first billing cycle of June 2019. OG&E is reserving the amounts collected through the interim surcharge, pending APSC approval of OG&E's filing. A hearing on the merits was held in December 2019. Parties submitted additional briefs to the APSC in March 2020, which were requested due to certain intervenors questioning whether a company can utilize an environmental compliance plan rider while also being regulated under a formula rate plan. The APSC Staff concurred with OG&E that the rider may run concurrently with a formula rate plan, and the Arkansas Attorney General and other intervenors were in opposition. On July 31, 2020, OG&E's request to recover its investment for these environmentally mandated costs through the interim surcharge was not approved, as the APSC indicated OG&E could otherwise recover this investment, such as through the Formula Rate Plan Rider. OG&E will return $5.1 million to customers that had been reserved for refund and will include these costs for recovery in its upcoming Formula Rate Plan filing. Net Metering Order On June 1, 2020, the APSC revised its net-metering rules. The revised rules retained 1:1 full credit for net excess generation of residential customers and commercial customers up to 1 MW without demand charges. For larger commercial customers, 1 MW to 20 MW, the APSC found that some cost shifting to non-net-metering customers may occur. While the rules retain 1:1 full credit for net excess generation, they allow for a grid charge. The grid charge is initially set at zero; however, a utility may request approval to revise the grid charge based on evidence that an unreasonable cost shift to non-net-metering customers is occurring. OG&E does not currently have a significant number of net-metering customers in Arkansas. OG&E is reviewing its existing net-metering tariffs considering the new rules and will request the APSC approve any changes that are believed to be necessary. OCC Proceedings Oklahoma Grid Enhancement Plan On February 24, 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. On May 19, 2020, the OCC temporarily suspended the procedural schedule in light of various conditions related to the COVID-19 pandemic and the uncertainty surrounding the method and date in which the hearing on the merits may occur. On July 9, 2020, a prehearing conference was held before the Administrative Law Judge to establish a procedural schedule and lift the stay ordered on May 19, 2020. On July 23, 2020, the OCC issued an order approving the amended procedural schedule and thereby lifting the stay. A hearing on the merits is scheduled for October 8, 2020. 2019 Oklahoma Fuel Prudency On June 16, 2020, the Public Utility Division Staff filed their application initiating the review of the 2019 fuel adjustment clause and prudence review. OG&E plans to file its Minimum Filing Requirements and Supporting Testimony on August 17, 2020. Oklahoma Retail Electric Supplier Certified Territory Act Causes Certain 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. If the OCC were to ultimately find that some or all of the customers being served are not exempted, then OG&E would have to evaluate the recoverability of some plant investments made to serve these customers. OG&E may also be required to reimburse certified territory suppliers for an amount of lost revenue. Currently, the People's Electric Cooperative, Inc. case has been stayed with the OCC, and an appeal has been filed with the Oklahoma Supreme Court.

Summary of Significant Accoun_2

Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Consolidation, Policy [Policy Text Block]	Organization The Company is a holding company with investments in energy and energy services providers offering physical delivery and related services for both electricity and natural gas primarily in the south-central U.S. The Company conducts these activities through two business segments: (i) electric utility and (ii) natural gas midstream operations. The accounts of the Company and its wholly-owned subsidiaries are included in the Condensed Consolidated Financial Statements. All intercompany transactions and balances are eliminated in consolidation. The Company 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. The electric utility segment generates, transmits, distributes and sells electric energy in Oklahoma and western Arkansas. Its operations are conducted through OG&E and 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 the Company. 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. The natural gas midstream operations segment represents the Company's investment in Enable through wholly-owned subsidiaries and ultimately OGE Holdings. Enable was formed in 2013, and its general partner is equally controlled by the Company and CenterPoint, who each have 50 percent management ownership. Based on the 50/50 management ownership, with neither company having control, the Company accounts for its interest in Enable using the equity method of accounting. Enable is primarily engaged in the business of gathering, processing, transporting and storing natural gas. Enable's natural gas gathering and processing assets are strategically located in four states and serve natural gas production in the Anadarko, Arkoma and Ark-La-Tex Basins. Enable also owns crude oil gathering assets in the Anadarko and Williston Basins. Enable has intrastate natural gas transportation and storage assets that are located in Oklahoma as well as interstate assets that extend from western Oklahoma and the Texas Panhandle to Louisiana, from Louisiana to Illinois and from Louisiana to Alabama.
Basis of Accounting, Policy [Policy Text Block]	Basis of Presentation The Condensed Consolidated Financial Statements included herein have been prepared by the Company, without audit, pursuant to the rules and regulations of the Securities and Exchange Commission. Certain information and footnote disclosures normally included in financial statements prepared in accordance with GAAP have been condensed or omitted pursuant to such rules and regulations; however, the Company believes that the disclosures are adequate to prevent the information presented from being misleading. In the opinion of management, all adjustments necessary to fairly present the consolidated financial position of the Company at June 30, 2020 and December 31, 2019, the consolidated results of its operations for the three and six months ended June 30, 2020 and 2019 and its consolidated cash flows for the six months ended June 30, 2020 and 2019 have been included and are of a normal, recurring nature except as otherwise disclosed. Management also has evaluated the impact of events occurring after June 30, 2020 up to the date of issuance of these Condensed Consolidated Financial Statements, and these statements contain all necessary adjustments and disclosures resulting from that evaluation.
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.
Equity Method Investments [Policy Text Block]	The natural gas midstream operations segment represents the Company's investment in Enable through wholly-owned subsidiaries and ultimately OGE Holdings. Enable was formed in 2013, and its general partner is equally controlled by the Company and CenterPoint, who each have 50 percent management ownership. Based on the 50/50 management ownership, with neither company having control, the Company accounts for its interest in Enable using the equity method of accounting. Enable is primarily engaged in the business of gathering, processing, transporting and storing natural gas. Enable's natural gas gathering and processing assets are strategically located in four states and serve natural gas production in the Anadarko, Arkoma and Ark-La-Tex Basins. Enable also owns crude oil gathering assets in the Anadarko and Williston Basins. Enable has intrastate natural gas transportation and storage assets that are located in Oklahoma as well as interstate assets that extend from western Oklahoma and the Texas Panhandle to Louisiana, from Louisiana to Illinois and from Louisiana to Alabama. Investment in Unconsolidated Affiliates The Company's investment in Enable is considered to be a variable interest entity because the owners of the equity at risk in this entity have disproportionate voting rights in relation to their obligations to absorb the entity's expected losses or to receive its expected residual returns. However, the Company is not considered the primary beneficiary of Enable since it does not have the power to direct the activities of Enable that are considered most significant to the economic performance of Enable; therefore, the Company accounts for its investment in Enable using the equity method of accounting. Under the equity method, the investment will be adjusted each period for contributions made, distributions received and the Company's share of the investee's comprehensive income as adjusted for basis differences. The Company's maximum exposure to loss related to Enable is limited to the Company's equity investment in Enable at June 30, 2020 as presented in Note 12. The Company evaluates its equity method investments for impairment when events or changes in circumstances indicate there is a loss in value of the investment that is other than a temporary decline. When indicators exist, the fair value is estimated and compared to the investment carrying value, and if any impairment is judgmentally determined to be other than temporary, the carrying value of the investment is written down to fair value. The Company determined, effective March 31, 2020, that an other than temporary decline in the value of the Company's investment in Enable had occurred. Further information detailing the results of the Company's impairment analysis and fair value measurement can be found in Notes 4 and 5. The Company considers distributions received from Enable, which do 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 Condensed Consolidated Statements of Cash Flows. The Company considers 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 Condensed Consolidated Statements of Cash Flows.
Fair Value of Financial Instruments, Policy [Policy Text Block]	The classification of the Company's 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).
Income Tax, Policy [Policy Text Block]	The Company files consolidated income tax returns in the U.S. federal jurisdiction and various state jurisdictions.Income taxes are generally allocated to each company in the affiliated group 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 the Company's effective tax rate.
Earnings Per Share, Policy [Policy Text Block]	Earnings (Loss) Per Share
Financing Receivable, Allowance for Credit Losses, Policy for Uncollectible Amounts	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 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. 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 Condensed Consolidated Balance Sheets and is included in the Other Operation and Maintenance in the Condensed Consolidated Statements of Income. 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 may be 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.

Investments, Equity Method and

Investments, Equity Method and Joint Ventures (Policies)	6 Months Ended
	Jun. 30, 2020
Equity Method Investments and Joint Ventures [Abstract]
Impairment or Disposal of Long-Lived Assets, Including Intangible Assets, Policy	The Company evaluates its equity method investment for impairment when factors indicate that a decline in the value of its investment has occurred and the carrying amount of its investment may not be recoverable. An impairment loss, based on the excess of the carrying value over estimated fair value of the investment, is recognized in earnings when an impairment is deemed to be other than temporary. Considerable judgment is used in determining if an impairment loss is other than temporary and the amount of any impairment. Effective March 31, 2020, the Company 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 the recent rapid deterioration, as well as the near term future outlook, of the midstream oil and gas industry. Accordingly, the Company recorded a $780.0 million impairment on its investment in Enable in March 2020, which is included in Equity in Earnings (Losses) of Unconsolidated Affiliates in the Company's 2020 Condensed Consolidated Income Statement. Further information concerning the fair value method used to measure the impairment on the Company's investment in Enable can be found in Note 5.

Fair Value Measures and Disclos

Fair Value Measures and Disclosures (Policies)	6 Months Ended
	Jun. 30, 2020
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments, Policy [Policy Text Block]	The classification of the Company's 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).

Summary of Significant Accoun_3

Summary of Significant Accounting Policies (Tables)	6 Months Ended
	Jun. 30, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Schedule of Regulatory Assets and Liabilities [Table Text Block]	The following table is a summary of OG&E's regulatory assets and liabilities. June 30, December 31, (In millions) 2020 2019 REGULATORY ASSETS Current: SPP cost tracker under recovery (A) $ 5.8 $ — Generation Capacity Replacement rider under recovery (A) 4.1 3.7 Fuel clause under recoveries — 39.5 Other (A) 6.8 5.5 Total current regulatory assets $ 16.7 $ 48.7 Non-current: Benefit obligations regulatory asset $ 163.0 $ 167.2 Deferred storm expenses 63.8 65.5 Sooner Dry Scrubbers 20.2 20.6 Smart Grid 14.8 18.4 Unamortized loss on reacquired debt 10.2 10.6 Arkansas deferred pension expenses 7.6 8.0 COVID-19 deferred expenses 3.8 — Pension tracker — 2.3 Other 16.0 13.4 Total non-current regulatory assets $ 299.4 $ 306.0 REGULATORY LIABILITIES Current: Fuel clause over recoveries $ 37.2 $ 4.8 Reserve for tax refund and interim surcharge (B) 5.9 12.7 Oklahoma demand program rider over recovery (B) 3.6 2.0 SPP cost tracker over recovery (B) — 2.6 Other (B) 5.7 6.9 Total current regulatory liabilities $ 52.4 $ 29.0 Non-current: Income taxes refundable to customers, net $ 882.6 $ 899.2 Accrued removal obligations, net 317.9 318.5 Pension tracker 0.4 — Other 5.3 5.8 Total non-current regulatory liabilities $ 1,206.2 $ 1,223.5 (A) Included in Other Current Assets in the Condensed Consolidated Balance Sheets.
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]	The following tables summarize changes in the components of accumulated other comprehensive income (loss) attributable to the Company during the six months ended June 30, 2020 and 2019. All amounts below are presented net of tax. (In millions) Pension Plan and Restoration of Retirement Income Plan Postretirement Benefit Plans Other Comprehensive Loss from Unconsolidated Affiliates Total Balance at December 31, 2019 $ (35.1) $ 7.8 $ (0.6) $ (27.9) Other comprehensive income (loss) before reclassifications — — (1.3) (1.3) Amounts reclassified from accumulated other comprehensive income (loss) 2.0 (0.9) — 1.1 Settlement cost 0.2 — — 0.2 Balance at June 30, 2020 $ (32.9) $ 6.9 $ (1.9) $ (27.9) (In millions) Pension Plan and Restoration of Retirement Income Plan Postretirement Benefit Plans Total Balance at December 31, 2018 $ (38.8) $ 9.9 $ (28.9) Amounts reclassified from accumulated other comprehensive income (loss) 1.7 (1.0) 0.7 Settlement cost 7.1 — 7.1 Balance at June 30, 2019 $ (30.0) $ 8.9 $ (21.1)
Schedule of Amounts Reclassified out of Accumulated Other Comprehensive Income [Table Text Block]	The following table summarizes significant amounts reclassified out of accumulated other comprehensive income (loss) by the respective line items in net income (loss) during the three and six months ended June 30, 2020 and 2019. Details about Accumulated Other Comprehensive Income (Loss) Components Amount Reclassified from Accumulated Other Comprehensive Income (Loss) Affected Line Item in the Consolidated Statements of Income Three Months Ended Six Months Ended June 30, June 30, (In millions) 2020 2019 2020 2019 Amortization of Pension Plan and Restoration of Retirement Income Plan items: Actuarial losses $ (1.5) $ (1.3) $ (2.6) $ (2.2) (A) Settlement cost (0.3) (0.6) (0.3) (9.4) (A) (1.8) (1.9) (2.9) (11.6) Income (Loss) Before Taxes (0.4) (0.4) (0.7) (2.8) Income Tax Expense (Benefit) $ (1.4) $ (1.5) $ (2.2) $ (8.8) Net Income (Loss) Amortization of postretirement benefit plans items: Prior service credit $ 0.5 $ 0.5 $ 1.1 $ 1.1 (A) Actuarial gains 0.1 0.1 0.1 0.1 (A) 0.6 0.6 1.2 1.2 Income (Loss) Before Taxes 0.1 0.1 0.3 0.2 Income Tax Expense (Benefit) $ 0.5 $ 0.5 $ 0.9 $ 1.0 Net Income (Loss) Total reclassifications for the period, net of tax $ (0.9) $ (1.0) $ (1.3) $ (7.8) Net Income (Loss) (A) These accumulated other comprehensive income (loss) components are included in the computation of net periodic benefit cost (see Note 11 for additional information).

Accounting Pronouncements (Tabl

Accounting Pronouncements (Tables)	6 Months Ended
	Jun. 30, 2020
Accounting Changes and Error Corrections [Abstract]
Accounting Standards Update and Change in Accounting Principle	The following table provides an overview of recently adopted accounting pronouncements and their impacts on the Company. ASU Number and Name Description Date of Adoption Financial Statements and Disclosures Impact ASU 2016-13, "Financial Instruments - Credit Losses: Measurement of Credit Losses on Financial Information" This standard requires entities to measure all expected credit losses of financial assets held at a reporting date based on historical experience, current conditions and reasonable and supportable forecasts in order to record credit losses in a more timely manner. January 1, 2020 Utilizing a modified-retrospective approach, the Company determined its only financial instrument requiring measurement under ASU 2016-13 is trade receivables. The Company considers both future economic conditions and historical data to measure the reserve for trade receivables under this standard and determined no adjustments to its reserve were necessary upon adoption. ASU 2018-15, "Intangibles - Goodwill and Other - Internal-Use Software (Subtopic 350-40)" The standard aligns requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. January 1, 2020 The new standard did not have a material effect on the Company's financial statements upon adoption. Prospectively, the Company records applicable capitalized implementation costs in Other Current Assets and related amortization expense in Other Operation and Maintenance. ASU 2018-13, "Fair Value Measurement (Topic 820): Disclosure Framework" The standard removes, adds or modifies disclosure requirements that impact all levels of the fair value hierarchy, as well as investments measured using the net asset value practical expedient. January 1, 2020 The Company applied the guidance on a retrospective or prospective basis, depending on the requirement, and did not experience a significant impact on its financial statement disclosures. ASU 2018-14, "Compensation - Retirement Benefits - Defined Benefit Plans - General (Subtopic 715-20)" The standard removes, adds or clarifies disclosure requirements for employers that sponsor defined benefit pension or other postretirement plans. January 1, 2020 The Company applied the guidance on a retrospective basis and did not experience a significant impact on its financial statement disclosures. ASU 2020-04, "Reference Rate Reform (Topic 848)" This standard provides optional expedients and exceptions, if certain criteria are met, for applying GAAP to contracts, hedging relationships and other transactions that reference LIBOR or another reference rate expected to be discontinued because of reference rate reform. January 1, 2020 The guidance did not have a material impact upon adoption, nor does the Company expect a material impact in the future, on its consolidated financial statements.

Revenue from Contracts with C_2

Revenue from Contracts with Customers (Tables)	6 Months Ended
	Jun. 30, 2020
Disaggregation of Revenue [Line Items]
Disaggregation of Revenue [Table Text Block]	The following table disaggregates the Company's revenues from contracts with customers by customer classification. The Company's operating revenues disaggregated by customer classification can be found in "OG&E (Electric Utility) Results of Operations" within "Item 2. Management's Discussion and Analysis of Financial Condition and Results of Operations." Three Months Ended June 30, Six Months Ended June 30, (In millions) 2020 2019 2020 2019 Residential $ 202.8 $ 182.3 $ 369.7 $ 373.5 Commercial 113.0 115.4 204.3 210.8 Industrial 44.7 52.9 86.2 105.2 Oilfield 38.4 48.9 76.6 98.3 Public authorities and street light 40.6 44.4 75.3 84.5 System sales revenues 439.5 443.9 812.1 872.3 Provision for rate refund (1.0) (0.5) (1.6) (0.6) Integrated market 8.5 10.3 15.7 17.0 Transmission 39.8 39.8 74.0 75.9 Other 5.2 7.6 12.2 13.9 Revenues from contracts with customers $ 492.0 $ 501.1 $ 912.4 $ 978.5

Investment in Unconsolidated _2

Investment in Unconsolidated Affiliates (Tables)	6 Months Ended
	Jun. 30, 2020
Reconciliation of Basis Difference [Line Items]
Reconciliation of Basis Difference [Table Text Block]	The following table reconciles the difference between OGE Energy's investment in Enable and its underlying equity in the net assets of Enable (basis difference) from December 31, 2019 to June 30, 2020. The basis difference is being amortized over approximately 30 years. (In millions) Basis difference at December 31, 2019 $ 652.5 Amortization of basis difference (A) (26.3) Impairment of OGE Energy's equity method investment in Enable 780.0 Basis difference at June 30, 2020 $ 1,406.2
Reconciliation of Equity in Earnings of Unconsolidated Affiliates [Table Text Block]	The following table reconciles the Company's equity in earnings (losses) of unconsolidated affiliates for the three and six months ended June 30, 2020 and 2019. Three Months Ended Six Months Ended June 30, June 30, (In millions) 2020 2019 2020 2019 Enable net income $ 35.0 $ 114.8 $ 138.0 $ 228.1 OGE Energy's percent ownership at period end 25.5 % 25.5 % 25.5 % 25.5 % OGE Energy's portion of Enable net income $ 8.8 $ 29.3 $ 35.1 $ 58.2 Amortization of basis difference and dilution recognition (A) 18.1 6.5 25.3 8.3 Impairment of OGE Energy's equity method investment in Enable — — (780.0) — Equity in earnings (losses) of unconsolidated affiliates $ 26.9 $ 35.8 $ (719.6) $ 66.5 (A) Includes loss on dilution, net of proportional basis difference recognition.
Schedule of Related Party Transactions [Table Text Block]	The following table summarizes related party transactions between OG&E and Enable during the three and six months ended June 30, 2020 and 2019. Three Months Ended Six Months Ended June 30, June 30, (In millions) 2020 2019 2020 2019 Operating revenues: Electricity to power electric compression assets $ 3.5 $ 3.8 $ 7.2 $ 7.6 Cost of sales: Natural gas transportation services $ 9.4 $ 9.3 $ 14.1 $ 24.1 Natural gas purchases (sales) $ (1.7) $ (3.3) $ (1.0) $ (4.3)
Summarized Balance Sheet Financial Information, Equity Method Investment [Table Text Block]	Summarized unaudited financial information for 100 percent of Enable is presented below at June 30, 2020 and December 31, 2019 and for the three and six months ended June 30, 2020 and 2019. June 30, December 31, Balance Sheet 2020 2019 (In millions) Current assets $ 374 $ 389 Non-current assets $ 11,687 $ 11,877 Current liabilities $ 290 $ 780 Non-current liabilities $ 4,454 $ 4,077
Summarized Income Statement Financial Information, Equity Method Investment [Table Text Block]	Three Months Ended Six Months Ended June 30, June 30, Income Statement 2020 2019 2020 2019 (In millions) Total revenues $ 515 $ 735 $ 1,163 $ 1,530 Cost of natural gas and NGLs $ 177 $ 317 $ 403 $ 695 Operating income $ 80 $ 167 $ 226 $ 332 Net income $ 35 $ 115 $ 138 $ 228

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 2020
Fair Value Disclosures [Abstract]
Schedule of Fair Value and Carrying Amount of PRM Financial Instruments [Table Text Block]	The following table summarizes the carrying amount and fair value of the Company's financial instruments at June 30, 2020 and December 31, 2019. June 30, December 31, 2020 2019 (In millions) Carrying Amount Fair Carrying Amount Fair Classification Long-term Debt (including Long-term Debt due within one year): OG&E Senior Notes $ 3,348.5 $ 4,024.7 $ 3,050.3 $ 3,500.4 Level 2 OG&E Industrial Authority Bonds $ 135.4 $ 135.4 $ 135.4 $ 135.4 Level 2 Tinker Debt $ 9.5 $ 10.7 $ 9.5 $ 10.0 Level 3

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	6 Months Ended
	Jun. 30, 2020
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based Payment Arrangement, Cost by Plan [Table Text Block]	The following table summarizes the Company's pre-tax compensation expense and related income tax benefit during the three and six months ended June 30, 2020 and 2019 related to the Company's performance units and restricted stock units. Three Months Ended June 30, Six Months Ended June 30, (In millions) 2020 2019 2020 2019 Performance units: Total shareholder return $ 2.0 $ 2.3 $ 3.7 $ 4.5 Earnings per share 0.1 0.4 0.3 0.9 Total performance units 2.1 2.7 4.0 5.4 Restricted stock units 0.2 0.2 0.3 0.5 Total compensation expense $ 2.3 $ 2.9 $ 4.3 $ 5.9 Income tax benefit $ 0.6 $ 0.7 $ 1.1 $ 1.5

Common Equity (Tables)

Common Equity (Tables)	6 Months Ended
	Jun. 30, 2020
Equity [Abstract]
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	The following table calculates basic and diluted earnings (loss) per share for the Company. Three Months Ended June 30, Six Months Ended June 30, (In millions except per share data) 2020 2019 2020 2019 Net income (loss) $ 85.9 $ 100.2 $ (405.9) $ 147.3 Average common shares outstanding: Basic average common shares outstanding 200.2 200.2 200.2 200.1 Effect of dilutive securities: Contingently issuable shares (performance and restricted stock units) 0.3 0.4 — 0.4 Diluted average common shares outstanding 200.5 200.6 200.2 200.5 Basic earnings (loss) per average common share $ 0.43 $ 0.50 $ (2.03) $ 0.74 Diluted earnings (loss) per average common share $ 0.43 $ 0.50 $ (2.03) $ 0.73 Anti-dilutive shares excluded from earnings per share calculation — — — —

Long-Term Debt (Tables)

Long-Term Debt (Tables)	6 Months Ended
	Jun. 30, 2020
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 bonds, which can be tendered at the option of the holder during the next 12 months, are included in the following table. Series Date Due Amount (In millions) 0.35% - 2.20% Garfield Industrial Authority, January 1, 2025 $ 47.0 0.37% - 1.50% Muskogee Industrial Authority, January 1, 2025 32.4 0.35% - 2.20% 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)	6 Months Ended
	Jun. 30, 2020
Short-term Debt [Abstract]
Schedule of Line of Credit Facilities [Table Text Block]	The following table provides information regarding the Company's revolving credit agreements at June 30, 2020. Aggregate Amount Weighted-Average Entity Commitment Outstanding (A) Interest Rate Expiration (In millions) OGE Energy (B) $ 450.0 $ — — % (D) March 8, 2023 OG&E (C) 450.0 0.3 1.15 % (D) March 8, 2023 Total $ 900.0 $ 0.3 1.15 % (A) Includes direct borrowings under the revolving credit agreements, commercial paper borrowings and letters of credit at June 30, 2020. (B) This bank facility is available to back up the Company'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.

Retirement Plans and Postreti_2

Retirement Plans and Postretirement Benefit Plans (Tables)	6 Months Ended
	Jun. 30, 2020
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]
Schedule of Defined Benefit Plans Disclosures [Table Text Block]	The following table presents the net periodic benefit cost components, before consideration of capitalized amounts, of the Company's Pension Plan, Restoration of Retirement Income Plan and postretirement benefit plans that are included in the Condensed Consolidated Financial Statements. Service cost is presented within Other Operation and Maintenance, and the remaining net periodic benefit cost components as listed in the table below are presented within Other Net Periodic Benefit Expense in the Company's Condensed Consolidated 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 Company's Condensed Consolidated Statements of Income. Pension Plan Restoration of Retirement Three Months Ended Six Months Ended Three Months Ended Six Months Ended June 30, June 30, June 30, June 30, (In millions) 2020 2019 2020 2019 2020 2019 2020 2019 Service cost $ 2.8 $ 2.8 $ 6.5 $ 6.3 $ 0.2 $ 0.1 $ 0.4 $ 0.2 Interest cost 4.6 5.2 9.2 10.9 — 0.1 0.1 0.2 Expected return on plan assets (9.2) (8.9) (18.6) (17.6) — — — — Amortization of net loss 4.6 4.8 8.4 8.6 0.2 0.1 0.3 0.2 Settlement cost — 0.9 — 20.6 0.3 — 0.3 — Total net periodic benefit cost 2.8 4.8 5.5 28.8 0.7 0.3 1.1 0.6 Less: Amount paid by unconsolidated affiliates 0.6 0.8 1.1 1.7 — — — — Net periodic benefit cost $ 2.2 $ 4.0 $ 4.4 $ 27.1 $ 0.7 $ 0.3 $ 1.1 $ 0.6 (A) In addition to the net periodic benefit cost amounts recognized, as presented in the table above, for the Pension and Restoration of Retirement Income Plans for the three and six months ended June 30, 2020 and 2019, the Company recognized the following: Three Months Ended June 30, Six Months Ended June 30, (In millions) 2020 2019 2020 2019 Increase (decrease) of pension expense to maintain allowed recoverable amount in Oklahoma jurisdiction (A) $ 1.6 $ (0.7) $ 3.3 $ (1.7) Deferral of pension expense related to pension settlement charges: Oklahoma jurisdiction (A) $ 0.3 $ 0.5 $ 0.3 $ 11.7 Arkansas jurisdiction (A) $ — $ 0.1 $ — $ 1.1 (A) Included in the pension regulatory asset or liability in each jurisdiction, as indicated in the regulatory assets and liabilities table in Note 1. Postretirement Benefit Plans Three Months Ended Six Months Ended June 30, June 30, (In millions) 2020 2019 2020 2019 Service cost $ — $ — $ 0.1 $ 0.1 Interest cost 1.0 1.4 2.1 2.8 Expected return on plan assets (0.4) (0.4) (0.9) (0.9) Amortization of net loss 0.4 0.4 1.0 1.0 Amortization of unrecognized prior service cost (A) (2.1) (2.1) (4.2) (4.2) Total net periodic benefit cost (1.1) (0.7) (1.9) (1.2) Less: Amount paid by unconsolidated affiliates (0.2) (0.1) (0.4) (0.3) Net periodic benefit cost $ (0.9) $ (0.6) $ (1.5) $ (0.9) (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. In addition to the net periodic benefit income amounts recognized, as presented in the table above, for the postretirement benefit plans for the three and six months ended June 30, 2020 and 2019, the Company recognized the following: Three Months Ended June 30, Six Months Ended June 30, (In millions) 2020 2019 2020 2019 Increase of postretirement expense to maintain allowed recoverable amount in Oklahoma jurisdiction (A) $ 0.6 $ 0.5 $ 0.8 $ 0.8
Schedule of Capitalized Pension and Postretirement Cost [Table Text Block]	Three Months Ended Six Months Ended June 30, June 30, (In millions) 2020 2019 2020 2019 Capitalized portion of net periodic pension benefit cost $ 0.8 $ 0.8 $ 1.8 $ 1.8 Capitalized portion of net periodic postretirement benefit cost $ 0.1 $ — $ 0.1 $ 0.1

Report of Business Segments (Ta

Report of Business Segments (Tables)	6 Months Ended
	Jun. 30, 2020
Segment Reporting [Abstract]
Schedule of Segment Reporting Information, by Segment [Table Text Block]	The following tables summarize the results of the Company's business segments during the three and six months ended June 30, 2020 and 2019. Three Months Ended June 30, 2020 Electric Utility Natural Gas Midstream Operations Other Eliminations Total (In millions) Operating revenues $ 503.5 $ — $ — $ — $ 503.5 Cost of sales 137.4 — — — 137.4 Other operation and maintenance 117.7 0.3 (0.5) — 117.5 Depreciation and amortization 97.3 — — — 97.3 Taxes other than income 25.0 0.1 0.8 — 25.9 Operating income (loss) 126.1 (0.4) (0.3) — 125.4 Equity in earnings of unconsolidated affiliates — 26.9 — — 26.9 Other income 0.5 — 1.7 (0.2) 2.0 Interest expense 39.3 — 1.7 (0.2) 40.8 Income tax expense 8.4 7.5 11.7 — 27.6 Net income (loss) $ 78.9 $ 19.0 $ (12.0) $ — $ 85.9 Investment in unconsolidated affiliates $ — $ 356.4 $ 20.1 $ — $ 376.5 Total assets $ 10,367.6 $ 360.2 $ 109.1 $ (397.8) $ 10,439.1 Three Months Ended June 30, 2019 Electric Utility Natural Gas Midstream Operations Other Eliminations Total (In millions) Operating revenues $ 513.7 $ — $ — $ — $ 513.7 Cost of sales 178.7 — — — 178.7 Other operation and maintenance 120.0 0.3 (0.5) — 119.8 Depreciation and amortization 84.3 — — — 84.3 Taxes other than income 20.1 0.1 0.7 — 20.9 Operating income (loss) 110.6 (0.4) (0.2) — 110.0 Equity in earnings of unconsolidated affiliates — 35.8 — — 35.8 Other income (expense) 1.5 (0.4) 1.0 (0.6) 1.5 Interest expense 33.3 — 3.2 (0.6) 35.9 Income tax expense (benefit) 4.3 8.1 (1.2) — 11.2 Net income (loss) $ 74.5 $ 26.9 $ (1.2) $ — $ 100.2 Investment in unconsolidated affiliates $ — $ 1,157.2 $ 14.1 $ — $ 1,171.3 Total assets $ 9,733.8 $ 1,160.0 $ 104.5 $ (112.1) $ 10,886.2 Six Months Ended June 30, 2020 Electric Utility Natural Gas Midstream Operations Other Eliminations Total (In millions) Operating revenues $ 934.8 $ — $ — $ — $ 934.8 Cost of sales 272.4 — — — 272.4 Other operation and maintenance 238.7 0.9 (2.1) — 237.5 Depreciation and amortization 191.7 — — — 191.7 Taxes other than income 48.9 0.2 2.4 — 51.5 Operating income (loss) 183.1 (1.1) (0.3) — 181.7 Equity in earnings (losses) of unconsolidated affiliates (A) — (719.6) — — (719.6) Other income 2.3 — 3.0 (1.2) 4.1 Interest expense 76.2 — 4.1 (1.2) 79.1 Income tax expense (benefit) 10.4 (171.7) (45.7) — (207.0) Net income (loss) $ 98.8 $ (549.0) $ 44.3 $ — $ (405.9) Investment in unconsolidated affiliates $ — $ 356.4 $ 20.1 $ — $ 376.5 Total assets $ 10,367.6 $ 360.2 $ 109.1 $ (397.8) $ 10,439.1 (A) In March 2020, the Company recorded a $780.0 million impairment on its investment in Enable, as further discussed in Notes 4 and 5. Six Months Ended June 30, 2019 Electric Utility Natural Gas Midstream Operations Other Eliminations Total (In millions) Operating revenues $ 1,003.7 $ — $ — $ — $ 1,003.7 Cost of sales 391.3 — — — 391.3 Other operation and maintenance 240.3 0.7 (2.2) — 238.8 Depreciation and amortization 166.7 — — — 166.7 Taxes other than income 44.5 0.3 2.4 — 47.2 Operating income (loss) 160.9 (1.0) (0.2) — 159.7 Equity in earnings of unconsolidated affiliates — 66.5 — — 66.5 Other income (expense) 4.1 (7.8) 1.7 (1.0) (3.0) Interest expense 65.7 — 5.8 (1.0) 70.5 Income tax expense (benefit) 5.2 9.5 (9.3) — 5.4 Net income $ 94.1 $ 48.2 $ 5.0 $ — $ 147.3 Investment in unconsolidated affiliates $ — $ 1,157.2 $ 14.1 $ — $ 1,171.3 Total assets $ 9,733.8 $ 1,160.0 $ 104.5 $ (112.1) $ 10,886.2

Summary of Significant Accoun_4

Summary of Significant Accounting Policies Equity Ownership (Details)	Jun. 30, 2020
CenterPoint [Member]
Percentage Share of Management Rights	50.00%
OGE Energy [Member]
Percentage Share of Management Rights	50.00%

Regulated Operations (Details)

Regulated Operations (Details) - USD ($) $ in Millions		Jun. 30, 2020	Dec. 31, 2019
Schedule of Regulatory Assets and Liabilities [Line Items]
Fuel clause under recoveries		$ 0	$ 39.5
Current Regulatory Assets		16.7	48.7
Non-Current Regulatory Assets		299.4	306
Current Regulatory Liabilities		52.4	29
Fuel clause over recoveries		37.2	4.8
Non-Current Regulatory Liabilities		1,206.2	1,223.5
Reserve for Tax Refund [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Current Regulatory Liabilities	[1]	5.9	12.7
SPP Cost Tracker Rider Over Recovery [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Current Regulatory Liabilities	[1]	0	2.6
Oklahoma Demand Program Over Recovery [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Current Regulatory Liabilities	[1]	3.6	2
Other (B)
Schedule of Regulatory Assets and Liabilities [Line Items]
Current Regulatory Liabilities	[1]	5.7	6.9
Non-Current Regulatory Liabilities		5.3	5.8
Income taxes recoverable from customers, net
Schedule of Regulatory Assets and Liabilities [Line Items]
Non-Current Regulatory Liabilities		882.6	899.2
Accrued removal obligations, net
Schedule of Regulatory Assets and Liabilities [Line Items]
Non-Current Regulatory Liabilities		317.9	318.5
Pension tracker
Schedule of Regulatory Assets and Liabilities [Line Items]
Non-Current Regulatory Liabilities		0.4	0
Production Tax Credit Rider [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Current Regulatory Assets	[2]	4.1	3.7
Benefit obligations regulatory asset
Schedule of Regulatory Assets and Liabilities [Line Items]
Non-Current Regulatory Assets		163	167.2
Deferred storm expenses
Schedule of Regulatory Assets and Liabilities [Line Items]
Non-Current Regulatory Assets		63.8	65.5
Smart Grid
Schedule of Regulatory Assets and Liabilities [Line Items]
Non-Current Regulatory Assets		14.8	18.4
Dry Scrubber Regulatory Asset [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Non-Current Regulatory Assets		20.2	20.6
Unamortized loss on reacquired debt
Schedule of Regulatory Assets and Liabilities [Line Items]
Non-Current Regulatory Assets		10.2	10.6
Deferred Pension Expenses [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Non-Current Regulatory Assets		7.6	8
Other Regulatory Asset [Member]
Schedule of Regulatory Assets and Liabilities [Line Items]
Current Regulatory Assets	[2]	6.8	5.5
Non-Current Regulatory Assets		16	13.4
Pension tracker
Schedule of Regulatory Assets and Liabilities [Line Items]
Non-Current Regulatory Assets		0	2.3
SPP Cost Tracker Rider Under Recovery
Schedule of Regulatory Assets and Liabilities [Line Items]
Current Regulatory Assets	[2]	5.8	0
COVID-19 Deferred Expenses
Schedule of Regulatory Assets and Liabilities [Line Items]
Non-Current Regulatory Assets		$ 3.8	$ 0
[1]	Included in Other Current Liabilities in the Condensed Consolidated Balance Sheets.
[2]	Included in Other Current Assets in the Condensed Consolidated Balance Sheets.

Summary of Significant Accoun_5

Summary of Significant Accounting Policies Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	6 Months Ended		12 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019	Dec. 31, 2018
Accumulated Other Comprehensive Income (Loss), Net of Tax	$ (27.9)	$ (21.1)	$ (27.9)	$ (28.9)
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(1.3)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	1.1	0.7
Accumulated Defined Benefit Plans Adjustment, Net Unamortized Gain (Loss) [Member] | Pension Plan [Member]
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax	(32.9)	(30)	(35.1)	(38.8)
Other Comprehensive Income (Loss), before Reclassifications, before Tax	0
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	2	1.7
Accumulated Defined Benefit Plans Adjustment, Net Unamortized Gain (Loss) [Member] | Other Postretirement Benefits Plan [Member]
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax	6.9	8.9	7.8	$ 9.9
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	0
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	(0.9)	(1)
Commodity Contract [Member]
Other Comprehensive Income (Loss), before Reclassifications, Net of Tax	(1.3)
Other Comprehensive Income (Loss), Net of Tax, Portion Attributable to Parent	(1.9)		$ (0.6)
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0
Settlement Cost [Member]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0.2	7.1
Settlement Cost [Member] | Accumulated Defined Benefit Plans Adjustment, Net Unamortized Gain (Loss) [Member] | Pension Plan [Member]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0.2	7.1
Settlement Cost [Member] | Accumulated Defined Benefit Plans Adjustment, Net Unamortized Gain (Loss) [Member] | Other Postretirement Benefits Plan [Member]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	0	$ 0
Settlement Cost [Member] | Commodity Contract [Member]
Reclassification from Accumulated Other Comprehensive Income, Current Period, Net of Tax	$ 0

Summary of Significant Accoun_6

Summary of Significant Accounting Policies Accumulated Other Comprehensive Income (Loss) Reclassifications out of AOCI (Details) - USD ($) $ in Millions		3 Months Ended		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Reclassification from AOCI, Current Period, Net of Tax, Attributable to Parent		$ (0.9)	$ (1)	$ (1.3)	$ (7.8)
Pension Plan [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax	[1]	(1.5)	(1.3)	(2.6)	(2.2)
Other Comprehensive Income (Loss), Defined Benefit Plan, Settlement and Curtailment Gain (Loss), before Tax	[1]	(0.3)	(0.6)	(0.3)	(9.4)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, before Tax		(1.8)	(1.9)	(2.9)	(11.6)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, Tax		(0.4)	(0.4)	(0.7)	(2.8)
Amounts reclassified from accumulated other comprehensive income (loss), net of tax		(1.4)	(1.5)	(2.2)	(8.8)
Other Postretirement Benefits Plan [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax	[1]	0.1	0.1	0.1	0.1
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, before Tax	[1]	0.5	0.5	1.1	1.1
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, before Tax		0.6	0.6	1.2	1.2
Other Comprehensive (Income) Loss, Defined Benefit Plan, Reclassification Adjustment from AOCI, Tax		0.1	0.1	0.3	0.2
Amounts reclassified from accumulated other comprehensive income (loss), net of tax		$ 0.5	$ 0.5	$ 0.9	$ 1
[1]	These accumulated other comprehensive income (loss) components are included in the computation of net periodic benefit cost (see Note 11 for additional information).

Revenue from Contracts with C_3

Revenue from Contracts with Customers (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	$ 492	$ 501.1	$ 912.4	$ 978.5
Residential
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	202.8	182.3	369.7	373.5
Commercial
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	113	115.4	204.3	210.8
Industrial
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	44.7	52.9	86.2	105.2
Oilfield
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	38.4	48.9	76.6	98.3
Public authorities and street light
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	40.6	44.4	75.3	84.5
System sales revenues
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	439.5	443.9	812.1	872.3
Provision for rate refund
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	(1)	(0.5)	(1.6)	(0.6)
Integrated market
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	8.5	10.3	15.7	17
Transmission
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	39.8	39.8	74	75.9
Other
Disaggregation of Revenue [Line Items]
Revenues from contracts with customers	$ 5.2	$ 7.6	$ 12.2	$ 13.9

Investment in Unconsolidated _3

Investment in Unconsolidated Affiliates (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020		Jun. 30, 2019	Dec. 31, 2019
Expected Settlement Charge			$ 16.5
Limited Partner Units Owned	111		111
Distribution Made to Limited Partner, Distributions Declared, Per Unit			$ 0.16525		$ 0.33050
Limited Liability Company or Limited Partnership, Members or Limited Partners, Ownership Interest	25.50%	25.50%	25.50%		25.50%
Equity in earnings (losses) of unconsolidated affiliates	$ 26.9	$ 35.8	$ (719.6)	[1]	$ 66.5
Equity Method Investment, Difference Between Carrying Amount and Underlying Equity	1,406.2		1,406.2			$ 652.5
Enable Midstream Partners [Member]
Distributions from unconsolidated affiliates	$ 18.3	$ 35.3	$ 55		$ 70.6
OGE Holdings [Member]
Limited Liability Company or Limited Partnership, Members or Limited Partners, Ownership Interest			25.50%
Enable Midstream Partners [Member]
Share Price	$ 4.68		$ 4.68
[1]	In March 2020, the Company recorded a $780.0 million impairment on its investment in Enable, as further discussed in Notes 4 and 5.

Investment in Unconsolidated _4

Investment in Unconsolidated Affiliates Related Party Transactions (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Related Party Transaction [Line Items]
Distribution Made to Limited Partner, Distributions Declared, Per Unit			$ 0.16525	$ 0.33050
Enable Midstream Partners [Member] | OG&E [Member]
Related Party Transaction [Line Items]
Revenue from Related Parties	$ 3.5	$ 3.8	$ 7.2	$ 7.6
Operating Costs Charged [Member] | Enable Midstream Partners [Member] | OGE Energy [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Selling, General and Administrative Expenses from Transactions with Related Party	0.1	0.1	0.2	0.2
Employment Costs [Member] | Enable Midstream Partners [Member] | OGE Energy [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Selling, General and Administrative Expenses from Transactions with Related Party	3.8	4	10.1	16.4
Natural Gas Transportation [Member] | Enable Midstream Partners [Member] | OG&E [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Purchases from Related Party	9.4	9.3	14.1	24.1
Natural Gas Purchases [Member] | Enable Midstream Partners [Member] | OG&E [Member]
Related Party Transaction [Line Items]
Related Party Transaction, Purchases from Related Party	(1.7)	$ (3.3)	(1)	$ (4.3)
Excluding Fuel Purchases [Member]
Related Party Transaction [Line Items]
Accounts receivable - unconsolidated affiliates	$ 2.2		$ 2.2		$ 0.8

Investment in Unconsolidated _5

Investment in Unconsolidated Affiliates Summarized Balance Sheet Information of Equity Method Investment (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Schedule of Equity Method Investments [Line Items]
Assets, Current	$ 499	$ 430.2
Liabilities, Current	594.6	657.9
Equity Method Investment, Nonconsolidated Investee or Group of Investees [Member]
Schedule of Equity Method Investments [Line Items]
Assets, Current	374	389
Assets, Noncurrent	11,687	11,877
Liabilities, Current	290	780
Liabilities, Noncurrent	$ 4,454	$ 4,077

Investment in Unconsolidated _6

Investment in Unconsolidated Affiliates Summarized Income Statement of Equity Method Investment (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019
Schedule of Equity Method Investments [Line Items]
Operating revenues	$ 503.5		$ 513.7		$ 934.8	$ 1,003.7
Operating Income (Loss)	125.4		110		181.7	159.7
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	85.9	$ (491.8)	100.2	$ 47.1	(405.9)	147.3
Equity Method Investment, Nonconsolidated Investee or Group of Investees [Member]
Schedule of Equity Method Investments [Line Items]
Operating revenues	515		735		1,163	1,530
Cost of Revenue	177		317		403	695
Operating Income (Loss)	80		167		226	332
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ 35		$ 114.8		$ 138	$ 228.1

Investment in Unconsolidated _7

Investment in Unconsolidated Affiliates Reconciliation of Equity in Earnings of Unconsolidated Affiliates (Details) - USD ($) $ in Millions		3 Months Ended				6 Months Ended
		Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020		Jun. 30, 2019	Dec. 31, 2019
Reconciliation of Equity in Earnings of Unconsolidated Affiliates [Line Items]
Equity Method Investment, Difference Between Carrying Amount and Underlying Equity		$ 1,406.2				$ 1,406.2			$ 652.5
Limited Liability Company or Limited Partnership, Members or Limited Partners, Ownership Interest		25.50%		25.50%		25.50%		25.50%
Proportionate Unconsolidated Affiliate Net Income		$ 8.8		$ 29.3		$ 35.1		$ 58.2
Equity in Earnings Amortization of Basis Difference	[1]	18.1		6.5		25.3		8.3
Income (Loss) from Equity Method Investments, Total		26.9		35.8		(719.6)	[2]	66.5
Asset Impairment Charges		0		0		(780)		0
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest		85.9	$ (491.8)	100.2	$ 47.1	(405.9)		147.3
Equity Method Investment, Nonconsolidated Investee or Group of Investees [Member]
Reconciliation of Equity in Earnings of Unconsolidated Affiliates [Line Items]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest		$ 35		$ 114.8		$ 138		$ 228.1
OGE Holdings [Member]
Reconciliation of Equity in Earnings of Unconsolidated Affiliates [Line Items]
Limited Liability Company or Limited Partnership, Members or Limited Partners, Ownership Interest						25.50%
OGE Energy [Member]
Reconciliation of Equity in Earnings of Unconsolidated Affiliates [Line Items]
Equity in Earnings Amortization of Basis Difference	[3]					$ 26.3
[1]	Includes loss on dilution, net of proportional basis difference recognition.
[2]	In March 2020, the Company recorded a $780.0 million impairment on its investment in Enable, as further discussed in Notes 4 and 5.
[3]	Includes proportional basis difference recognition due to dilution.

Fair Value Measurements Carryin

Fair Value Measurements Carrying and Fair Value Amounts (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
OG&E Senior Notes [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-Term Debt, Carrying Amount	$ 3,348.5	$ 3,050.3
Long-Term Debt, Fair Value	4,024.7	3,500.4
OG&E Industrial Authority Bonds [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Long-Term Debt, Carrying Amount	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]
Long-Term Debt, Carrying Amount	9.5	9.5
Long-Term Debt, Fair Value	10.7	10
Fair Value, 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	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
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			247,073
Stock-Based Compensation Activity
Income tax benefit	$ 0.6	$ 0.7	$ 1.1	$ 1.5
Treasury Stock, Shares, Acquired			255,000
Treasury Stock Acquired, Average Cost Per Share			$ 38.04
Performance Shares [Member]
Stock-Based Compensation Activity
Compensation expense	2.1	2.7	$ 4	5.4
Restricted stock units
Stock-Based Compensation Activity
Compensation expense	0.2	0.2	0.3	0.5
Share-based Payment Arrangement [Member]
Stock-Based Compensation Activity
Compensation expense	2.3	2.9	4.3	5.9
Total Shareholder Return [Member] | Performance Shares [Member]
Stock-Based Compensation Activity
Compensation expense	2	2.3	3.7	4.5
Performance Units Related to Earnings Per Share [Member] | Performance Shares [Member]
Stock-Based Compensation Activity
Compensation expense	$ 0.1	$ 0.4	$ 0.3	$ 0.9

Income Taxes (Details)

Income Taxes (Details) - USD ($) $ in Millions	Jun. 30, 2020	Dec. 31, 2019
Non-Current Regulatory Liabilities	$ 1,206.2	$ 1,223.5

Common Equity Automatic Dividen

Common Equity Automatic Dividend Reinvestment and Stock Purchase Plan (Details) - shares	3 Months Ended	6 Months Ended
	Jun. 30, 2020	Jun. 30, 2020
Automatic Dividend Reinvestment and Stock Purchase Plan [Member]
Stock Issued During Period, Shares, New Issues	0	0

Common Equity Earnings Per Shar

Common Equity Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020	Jun. 30, 2019
Equity [Abstract]
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ 85.9	$ (491.8)	$ 100.2	$ 47.1	$ (405.9)	$ 147.3
Basic average common shares outstanding	200.2		200.2		200.2	200.1
Contingently issuable shares (performance and restricted stock units)	0.3		0.4		0	0.4
Diluted average common shares outstanding	200.5		200.6		200.2	200.5
Earnings Per Share, Basic and Diluted [Abstract]
Basic earnings (loss) per average common share	$ 0.43		$ 0.50		$ (2.03)	$ 0.74
Diluted earnings (loss) per average common share	$ 0.43		$ 0.50		$ (2.03)	$ 0.73
Anti-dilutive shares excluded from earnings per share calculation	0		0		0	0

Long-Term Debt (Details)

Long-Term Debt (Details) $ in Millions	6 Months Ended
	Jun. 30, 2020USD ($)
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	3.25%
Debt Instrument, Maturity Date	Apr. 1, 2030
Percent of Principal Amount Subject to Optional Tender	100.00%
Debt Instrument, Face Amount	$ 300
Garfield Industrial Authority Bond [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date	Jan. 1, 2025
Muskogee Industrial Authority Bond Due 2025 [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date	Jan. 1, 2025
Muskogee Industrial Authority Bond Due 2027 [Member]
Debt Instrument [Line Items]
Debt Instrument, Maturity Date	Jun. 1, 2027
Redeemable during the next 12 months
Debt Instrument [Line Items]
Long-term Debt	$ 135.4
OG&E [Member] | Redeemable during the next 12 months | Garfield Industrial Authority Bond [Member]
Debt Instrument [Line Items]
Long term debt	47
OG&E [Member] | Redeemable during the next 12 months | Muskogee Industrial Authority Bond Due 2025 [Member]
Debt Instrument [Line Items]
Long term debt	32.4
OG&E [Member] | Redeemable during the next 12 months | Muskogee Industrial Authority Bond Due 2027 [Member]
Debt Instrument [Line Items]
Long term debt	$ 56
Minimum [Member] | Redeemable during the next 12 months | Garfield Industrial Authority Bond [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	0.35%
Minimum [Member] | Redeemable during the next 12 months | Muskogee Industrial Authority Bond Due 2025 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	0.37%
Minimum [Member] | Redeemable during the next 12 months | Muskogee Industrial Authority Bond Due 2027 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	0.35%
Maximum [Member] | Redeemable during the next 12 months | Garfield Industrial Authority Bond [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.20%
Maximum [Member] | Redeemable during the next 12 months | Muskogee Industrial Authority Bond Due 2025 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	1.50%
Maximum [Member] | Redeemable during the next 12 months | Muskogee Industrial Authority Bond Due 2027 [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	2.20%

Short-Term Debt and Credit Fa_3

Short-Term Debt and Credit Facilities (Details) - USD ($) $ in Millions		6 Months Ended
		Jun. 30, 2020	Apr. 01, 2020	Dec. 31, 2019
Line of Credit Facility [Line Items]
Short-term debt		$ 75		$ 112
Line of Credit Facility [Abstract]
Aggregate Commitment		900
Long-term Line of Credit	[1]	$ 0.3
Weighted Average Interest Rate		1.15%	1.25%
Short-term Bank Loans and Notes Payable		$ 75
OGE Energy [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Current Borrowing Capacity	[2]	450
Line of Credit Facility [Abstract]
Long-term Line of Credit	[1],[2]	$ 0
Weighted Average Interest Rate	[2],[3]	0.00%
Maturity	[2]	Mar. 8, 2023
OG&E [Member]
Line of Credit Facility [Line Items]
Line of Credit Facility, Current Borrowing Capacity	[4]	$ 450
Line of Credit Facility [Abstract]
Letters of Credit Outstanding, Amount	[1],[4]	$ 0.3
Weighted Average Interest Rate	[3],[4]	1.15%
Maturity	[4]	Mar. 8, 2023
Short Term Borrowing Capacity That Has Regulatory Approval		$ 800
Period For Which Regulatory Approval Has Been Given to Acquire Short Term Debt		2 years
[1]	Includes direct borrowings under the revolving credit agreements, commercial paper borrowings and letters of credit at June 30, 2020.
[2]	This bank facility is available to back up the Company'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]	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		3 Months Ended		6 Months Ended
		Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Pension Plan [Member]
Other Comprehensive Income (Loss), Defined Benefit Plan, Adjustment for Settlement or Curtailment Gain (Loss), Tax		$ 0.1	$ 0.1	$ 0.1	$ 2.3
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost		2.8	2.8	6.5	6.3
Interest cost		4.6	5.2	9.2	10.9
Expected return on plan assets		(9.2)	(8.9)	(18.6)	(17.6)
Amortization of net loss		4.6	4.8	8.4	8.6
Settlement cost		0	0.9	0	20.6
Total net periodic benefit cost		2.8	4.8	5.5	28.8
Amount Attributable to Unconsolidated Affiliates		0.6	0.8	1.1	1.7
Net periodic benefit cost		2.2	4	4.4	27.1
Capitalized portion of net periodic pension benefit cost		0.8	0.8	1.8	1.8
Other Pension Plan [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost		0.2	0.1	0.4	0.2
Interest cost		0	0.1	0.1	0.2
Expected return on plan assets		0	0	0	0
Amortization of net loss		0.2	0.1	0.3	0.2
Settlement cost		0.3	0	0.3	0
Total net periodic benefit cost		0.7	0.3	1.1	0.6
Amount Attributable to Unconsolidated Affiliates		0	0	0	0
Net periodic benefit cost		0.7	0.3	1.1	0.6
Postretirement Benefit Plan [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost		0	0	0.1	0.1
Interest cost		1	1.4	2.1	2.8
Expected return on plan assets		(0.4)	(0.4)	(0.9)	(0.9)
Amortization of net loss		0.4	0.4	1	1
Defined Benefit Plan, Amortization of Prior Service Cost (Credit)	[1]	(2.1)	(2.1)	(4.2)	(4.2)
Amount Attributable to Unconsolidated Affiliates		(0.2)	(0.1)	(0.4)	(0.3)
Capitalized portion of net periodic pension benefit cost		0.1	0	0.1	0.1
Postretirement Benefit Costs
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Total net periodic benefit cost		(1.1)	(0.7)	(1.9)	(1.2)
Net periodic benefit cost		(0.9)	(0.6)	(1.5)	(0.9)
OKLAHOMA | Pension Plan [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Settlement cost	[2]	0.3	0.5	0.3	11.7
Additional Pension Expense to Meet State Requirements	[2]	1.6	(0.7)	3.3	(1.7)
OKLAHOMA | Postretirement Benefit Plan [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Additional Pension Expense to Meet State Requirements	[3]	0.6	0.5	0.8	0.8
ARKANSAS | Pension Plan [Member]
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Settlement cost	[2]	$ 0	$ 0.1	$ 0	$ 1.1
[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]	Included in the pension regulatory asset or liability in each jurisdiction, as indicated in the regulatory assets and liabilities table in Note 1.
[3]	Included in the Pension tracker, as presented in the regulatory assets and liabilities table in Note 1.

Report of Business Segments (De

Report of Business Segments (Details) - USD ($) $ in Millions	3 Months Ended				6 Months Ended
	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Mar. 31, 2019	Jun. 30, 2020		Jun. 30, 2019	Dec. 31, 2019
Segment Reporting Information [Line Items]
Operating revenues	$ 503.5		$ 513.7		$ 934.8		$ 1,003.7
Cost of sales	137.4		178.7		272.4		391.3
Other operation and maintenance	117.5		119.8		237.5		238.8
Depreciation and amortization	97.3		84.3		191.7		166.7
Taxes other than income	25.9		20.9		51.5		47.2
OPERATING INCOME	125.4		110		181.7		159.7
Equity in earnings of unconsolidated affiliates	26.9		35.8		(719.6)	[1]	66.5
Other income	2		1.5		4.1		(3)
Interest expense	40.8		35.9		79.1		70.5
Income tax expense	27.6		11.2		(207)		5.4
Net income (loss)	85.9	$ (491.8)	100.2	$ 47.1	(405.9)		147.3
Investment in unconsolidated affiliates	376.5		1,171.3		376.5		1,171.3	$ 1,151.5
Total assets	10,439.1		10,886.2		10,439.1		10,886.2	$ 11,024.3
Electric Utility [Member]
Segment Reporting Information [Line Items]
Operating revenues	503.5		513.7		934.8		1,003.7
Cost of sales	137.4		178.7		272.4		391.3
Other operation and maintenance	117.7		120		238.7		240.3
Depreciation and amortization	97.3		84.3		191.7		166.7
Taxes other than income	25		20.1		48.9		44.5
OPERATING INCOME	126.1		110.6		183.1		160.9
Equity in earnings of unconsolidated affiliates	0		0		0	[1]	0
Other income	0.5		1.5		2.3		4.1
Interest expense	39.3		33.3		76.2		65.7
Income tax expense	8.4		4.3		10.4		5.2
Net income (loss)	78.9		74.5		98.8		94.1
Investment in unconsolidated affiliates	0		0		0		0
Total assets	10,367.6		9,733.8		10,367.6		9,733.8
Natural Gas Midstream Operations [Member]
Segment Reporting Information [Line Items]
Operating revenues	0		0		0		0
Cost of sales	0		0		0		0
Other operation and maintenance	0.3		0.3		0.9		0.7
Depreciation and amortization	0		0		0		0
Taxes other than income	0.1		0.1		0.2		0.3
OPERATING INCOME	(0.4)		(0.4)		(1.1)		(1)
Equity in earnings of unconsolidated affiliates	26.9		35.8		(719.6)	[1]	66.5
Other income	0		(0.4)		0		(7.8)
Interest expense	0		0		0		0
Income tax expense	7.5		8.1		(171.7)		9.5
Net income (loss)	19		26.9		(549)		48.2
Investment in unconsolidated affiliates	356.4		1,157.2		356.4		1,157.2
Total assets	360.2		1,160		360.2		1,160
Other Operations [Member]
Segment Reporting Information [Line Items]
Operating revenues	0		0		0		0
Cost of sales	0		0		0		0
Other operation and maintenance	(0.5)		(0.5)		(2.1)		(2.2)
Depreciation and amortization	0		0		0		0
Taxes other than income	0.8		0.7		2.4		2.4
OPERATING INCOME	(0.3)		(0.2)		(0.3)		(0.2)
Equity in earnings of unconsolidated affiliates	0		0		0	[1]	0
Other income	1.7		1		3		1.7
Interest expense	1.7		3.2		4.1		5.8
Income tax expense	11.7		(1.2)		(45.7)		(9.3)
Net income (loss)	(12)		(1.2)		44.3		5
Investment in unconsolidated affiliates	20.1		14.1		20.1		14.1
Total assets	109.1		104.5		109.1		104.5
Eliminations [Member]
Segment Reporting Information [Line Items]
Operating revenues	0		0		0		0
Cost of sales	0		0		0		0
Other operation and maintenance	0		0		0		0
Depreciation and amortization	0		0		0		0
Taxes other than income	0		0		0		0
OPERATING INCOME	0		0		0		0
Equity in earnings of unconsolidated affiliates	0		0		0	[1]	0
Other income	(0.2)		(0.6)		(1.2)		(1)
Interest expense	(0.2)		(0.6)		(1.2)		(1)
Income tax expense	0		0		0		0
Net income (loss)	0		0		0		0
Investment in unconsolidated affiliates	0		0		0		0
Total assets	$ (397.8)		$ (112.1)		$ (397.8)		$ (112.1)
[1]	In March 2020, the Company recorded a $780.0 million impairment on its investment in Enable, as further discussed in Notes 4 and 5.

Rate Matters and Regulation Rat

Rate Matters and Regulation Rate Matters and Regulation (Details) $ in Millions	6 Months Ended
	Jun. 30, 2020USD ($)
Public Utilities, Requested Rate Increase (Decrease), Amount	$ 5.2
Estimated Refund to SPP	13
Investment in Grid Enhancement	800
Arkansas Environmental Refund	5.1
Impact to Company [Member]
Estimated Refund to SPP	5
Customer Impact [Member]
Estimated Refund to SPP	$ 8