OGE Energy (OGE) 10-Q6 Nov 132013 FY Quarterly reportFinancial data

Company Profile

Document_and_Entity_Informatio

Document and Entity Information Document	9 Months Ended
Document and Entity Information Document	Sep. 30, 2013
Document Information [Line Items]	'
Entity Registrant Name	'OGE ENERGY CORP.
Entity Central Index Key	'0001021635
Current Fiscal Year End Date	'--12-31
Entity Filer Category	'Large Accelerated Filer
Document Type	'10-Q
Document Period End Date	30-Sep-13
Document Fiscal Year Focus	'2013
Document Fiscal Period Focus	'FY
Amendment Flag	'false
Entity Common Stock, Shares Outstanding	198,453,261

CONDENSED_CONSOLIDATED_STATEME

CONDENSED CONSOLIDATED STATEMENTS OF INCOME (Unaudited) (USD $)	3 Months Ended		9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
OPERATING REVENUES	'	'	'	'
Electric Utility operating revenues	$723.20	$721	$1,753.30	$1,675.70
Natural Gas Midstream Operations operating revenues (Note 1)	0	392.4	605.5	1,133.40
Total operating revenues	723.2	1,113.40	2,358.80	2,809.10
COST OF GOODS SOLD (exclusive of depreciation and amortization shown below)	'	'	'	'
Electric Utility cost of goods sold	273	259.8	715.2	636.1
Natural Gas Midstream Operations cost of goods sold (Note 1)	0	279.8	481.4	798.1
Total cost of goods sold	273	539.6	1,196.60	1,434.20
Gross margin on revenues	450.2	573.8	1,162.20	1,374.90
OPERATING EXPENSES	'	'	'	'
Other operation and maintenance	102.2	147.1	372.2	447.7
Depreciation and amortization	65.4	93	231.7	270.1
Impairment of assets	0	0	0	0.3
Gain on insurance proceeds	0	0	0	-7.5
Taxes other than income	21.7	29.7	78.1	84.7
Total operating expenses	189.3	269.8	682	795.3
OPERATING INCOME	260.9	304	480.2	579.6
OTHER INCOME (EXPENSE)	'	'	'	'
Equity in earnings of unconsolidated affiliates (Note 1)	46	0	64.5	0
Allowance for equity funds used during construction	1.7	1.3	4.4	4.9
Other income	6.2	2.6	25.4	12.8
Other expense	-5.2	-5.6	-15.9	-11.1
Net other income (expense)	48.7	-1.7	78.4	6.6
INTEREST EXPENSE	'	'	'	'
Interest on long-term debt	35	40.2	110.7	118.3
Allowance for borrowed funds used during construction	-0.9	-0.8	-2.3	-2.8
Interest on short-term debt and other interest charges	-0.4	2.2	3.8	6.6
Interest expense	33.7	41.6	112.2	122.1
INCOME BEFORE TAXES	275.9	260.7	446.4	464.1
INCOME TAX EXPENSE	60.7	68.3	110.2	122.6
NET INCOME	215.2	192.4	336.2	341.5
Less: Net income attributable to noncontrolling interests	0	6.9	6.2	25
NET INCOME ATTRIBUTABLE TO OGE ENERGY	$215.20	$185.50	$330	$316.50
BASIC AVERAGE COMMON SHARES OUTSTANDING	198.4	197.4	198.1	197
DILUTED AVERAGE COMMON SHARES OUTSTANDING	199.7	198.3	199.3	197.9
BASIC EARNINGS PER AVERAGE COMMON SHARE ATTRIBUTABLE TO OGE ENERGY COMMON SHAREHOLDERS	$1.08	$0.94	$1.67	$1.61
DILUTED EARNINGS PER AVERAGE COMMON SHARES ATTRIBUTABLE TO OGE ENERGY COMMON SHAREHOLDERS	$1.08	$0.94	$1.66	$1.60
DIVIDENDS DECLARED PER COMMON SHARE	$0.21	$0.20	$0.63	$0.59

CONDENSED_CONSOLIDATED_STATEME1

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Net income	$215.20	$192.40	$336.20	$341.50
Pension Plan and Restoration of Retirement Income Plan:	'	'	'	'
Amortization of deferred net loss, net of tax of $0.6, $0.4, $1.8 and $1.3, respectively	0.9	0.8	2.8	2.3
Amortization of prior service cost, net of tax of $0, $0, $0 and $0.1, respectively	0	0	0	0.1
Postretirement Benefit Plans:	'	'	'	'
Amortization of deferred net loss, net of tax of $0.3, $0.2, $0.9 and $0.8, respectively	0.6	0.5	1.6	1.5
Amortization of deferred net transition obligation, net of tax of $0, $0.1, $0 and $0.1, respectively	0	0.1	0	0.1
Amortization of prior service cost, net of tax of $(0.3), ($0.3), $(0.8) and ($0.8), respectively	-0.5	-0.5	-1.4	-1.4
Deferred commodity contracts hedging gains reclassified in net income, net of tax of $0.3, $0, $0.2 and ($1.6), respectively	0.3	0	0.2	-3.6
Deferred commodity contracts hedging losses, net of tax of $0, ($0.3), $0 and ($0.5), respectively	0	-0.5	0	-0.5
Amortization of deferred interest rate swap hedging losses, net of tax of $0, $0, $0.1 and $0.1, respectively	0.1	0.1	0.2	0.2
Other comprehensive income (loss), net of tax	1.4	0.5	3.4	-1.3
Comprehensive income (loss)	216.6	192.9	339.6	340.2
Less: Comprehensive income attributable to noncontrolling interests	0	6.9	6.3	24.1
Less: Deconsolidation of Enogex Holdings	0	0	6.1	0
Total comprehensive income attributable to OGE Energy	$216.60	$186	$327.20	$316.10

CONDENSED_CONSOLIDATED_STATEME2

CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME (Unaudited) Parenthetical (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Pension Plan and Restoration of Retirement Income Plan:	'	'	'	'
Amortization of deferred net loss	$0.60	$0.40	$1.80	$1.30
Amortization of prior service cost	0	0	0	0.1
Postretirement Benefit Plans:	'	'	'	'
Amortization of deferred net loss	0.3	0.2	0.9	0.8
Amortization of deferred net transition obligation	0	0.1	0	0.1
Amortization of prior service cost	-0.3	-0.3	-0.8	-0.8
Deferred commodity contracts hedging gains reclassified in net income	0.3	0	0.2	-1.6
Deferred commodity contracts hedging losses	0	-0.3	0	-0.5
Amortization of deferred interest rate swap hedging losses	$0	$0	$0.10	$0.10

CONDENSED_CONSOLIDATED_STATEME3

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012
CASH FLOWS FROM OPERATING ACTIVITIES	'	'
Net income	$336.20	$341.50
Adjustments to reconcile net income to net cash provided from operating activities	'	'
Depreciation and amortization	233	273
Impairment of assets	0	0.3
Deferred income taxes and investment tax credits, net	106.5	130.9
Equity in earnings of unconsolidated affiliates	-64.5	0
Allowance for equity funds used during construction	-4.4	-4.9
(Gain) loss on disposition and abandonment of assets	-8.7	-1.8
Gain on insurance proceeds	0	-7.5
Stock-based compensation	-4.9	-7.1
Distributions from unconsolidated affiliates	17.4	0
Regulatory assets	7.4	17.5
Regulatory liabilities	-16.9	-12.8
Other assets	-9.2	-3.1
Other liabilities	-18.5	-22.4
Change in certain current assets and liabilities	'	'
Accounts receivable, net	-111.8	-68.2
Accrued unbilled revenues	-13.3	-3.2
Income taxes receivable	1.6	1
Fuel, materials and supplies inventories	5.2	13.7
Fuel clause under recoveries	0	1
Other current assets	-0.2	-11.7
Accounts payable	-15.3	-81.5
Accounts payable - unconsolidated affiliates	4.9	0
Fuel clause over recoveries	-97.2	99.4
Other current liabilities	3.9	20.3
Net Cash Provided from Operating Activities	351.2	678
CASH FLOWS FROM INVESTING ACTIVITIES	'	'
Capital expenditures (less allowance for equity funds used during construction)	-772.9	-792.8
Investment in unconsolidated affiliates	-2.7	0
Acquisition of gathering assets	0	-80.5
Proceeds from insurance	0	7.6
Reimbursement of capital expenditures	0	28.2
Proceeds from sale of assets	36.2	0.9
Net Cash Used in Investing Activities	-739.4	-836.6
CASH FLOWS FROM FINANCING ACTIVITIES	'	'
Proceeds from long-term debt	247.4	250
Changes in advances with unconsolidated affiliates	131.8	0
Contributions from noncontrolling interest partners	107	1
Increase in short-term debt	16.1	178.5
Issuance of common stock	10.8	10.9
Repayment of line of credit	0	-150
Payment of long-term debt	-0.2	0
Distributions to noncontrolling interest partners	-2.5	-10.3
Dividends paid on common stock	-124	-115.9
Net Cash Provided from Financing Activities	386.4	164.2
NET (DECREASE) INCREASE IN CASH AND CASH EQUIVALENTS	-1.8	5.6
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	1.8	4.6
CASH AND CASH EQUIVALENTS AT END OF PERIOD	$0	$10.20

CONDENSED_CONSOLIDATED_BALANCE

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
CURRENT ASSETS	'	'
Cash and cash equivalents	$0	$1.80
Accounts receivable, less reserve of $2.0 and $2.6, respectively	257.2	295.3
Accounts receivable - unconsolidated affiliates	9	0
Accrued unbilled revenues	70.7	57.4
Income taxes receivable	5.6	7.2
Fuel inventories	75.5	93.3
Materials and supplies, at average cost	79.5	80.9
Deferred income taxes	230.2	187.7
Assets held for sale	0	25.5
Other	30.3	45.1
Total current assets	758	794.2
OTHER PROPERTY AND INVESTMENTS	'	'
Investment in unconsolidated affiliates	1,295.80	0
Other	56.2	52.2
Total other property and investments	1,352	52.2
PROPERTY, PLANT AND EQUIPMENT	'	'
In service	8,929.50	11,504.40
Construction work in progress	501.1	387.5
Total property, plant and equipment	9,430.60	11,891.90
Less accumulated depreciation	2,935	3,547.10
Net property, plant and equipment	6,495.60	8,344.80
DEFERRED CHARGES AND OTHER ASSETS	'	'
Regulatory assets	496.2	510.6
Intangible assets, net	0	127.4
Goodwill	0	39.4
Other	42.4	53.6
Total deferred charges and other assets	538.6	731
TOTAL ASSETS	9,144.20	9,922.20
CURRENT LIABILITIES	'	'
Short-term debt	447	430.9
Accounts payable	171.1	396.7
Dividends payable	41.4	41.2
Customer deposits	69.5	70.3
Accrued taxes	57.2	48.1
Accrued interest	33.6	55
Accrued compensation	53.3	55.2
Fuel clause over recoveries	12	109.2
Other	56.4	69.8
Total current liabilities	941.5	1,276.40
LONG-TERM DEBT	2,400	2,848.60
DEFERRED CREDITS AND OTHER LIABILITIES	'	'
Accrued benefit obligations	367.7	399.8
Deferred income taxes	2,105.30	1,948.80
Deferred investment tax credits	2.4	3.9
Regulatory liabilities	242.7	245.1
Deferred revenues	0.3	37.7
Other	89.7	89.5
Total deferred credits and other liabilities	2,808.10	2,724.80
Total liabilities	6,149.60	6,849.80
COMMITMENTS AND CONTINGENCIES (NOTE 13)	'	'
STOCKHOLDERS' EQUITY	'	'
Common stockholders' equity	1,067.80	1,047.40
Retained earnings	1,978.70	1,772.40
Accumulated other comprehensive loss, net of tax	-51.9	-49.1
Treasury stock, at cost	0	-3.5
Total OGE Energy stockholders' equity	2,994.60	2,767.20
Noncontrolling interests	0	305.2
Total stockholders' equity	2,994.60	3,072.40
TOTAL LIABILITIES AND STOCKHOLDERS' EQUITY	$9,144.20	$9,922.20

CONDENSED_CONSOLIDATED_BALANCE1

CONDENSED CONSOLIDATED BALANCE SHEETS (Unaudited) Parenthetical (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Allowance for Doubtful Accounts Receivable	$0	$2.60

CONDENSED_CONSOLIDATED_STATEME4

CONDENSED CONSOLIDATED STATEMENTS OF CHANGES IN STOCKHOLDERS' EQUITY (Unaudited) (USD $)	Total	Common Stock	Premium on Common Stock	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interest	Treasury Stock
In Millions, unless otherwise specified	Total	Common Stock	Premium on Common Stock	Retained Earnings	Accumulated Other Comprehensive Income (Loss)	Noncontrolling Interest	Treasury Stock
Balance at Dec. 31, 2011	$2,819.30	$1	$1,034.30	$1,574.80	($40.60)	$256	($6.20)
Changes in Stockholders' Equity	'	'	'	'	'	'	'
Net income	341.5	0	0	316.5	0	25	0
Other comprehensive income (loss), net of tax	-1.3	0	0	0	-0.4	-0.9	0
Dividends declared on common stock	-116.2	0	0	-116.2	0	0	0
Issuance of common stock	10.9	0	10.9	0	0	0	0
Stock-based compensation and other	-8.4	0	-11.6	0	0	-2.9	6.1
Contributions from noncontrolling interest partners	1	0	0	0	0	1	0
Distributions to noncontrolling interest partners	-10.3	0	0	0	0	-10.3	0
Balance at Sep. 30, 2012	3,036.50	1	1,033.60	1,775.10	-41	267.9	-0.1
Balance at Dec. 31, 2012	3,072.40	1	1,046.40	1,772.40	-49.1	305.2	-3.5
Changes in Stockholders' Equity	'	'	'	'	'	'	'
Net income	336.2	0	0	330	0	6.2	0
Other comprehensive income (loss), net of tax	3.4	0	0	0	3.3	0.1	0
Dividends declared on common stock	-124.2	0	0	-124.2	0	0	0
Issuance of common stock	10.8	0	10.8	0	0	0	0
Stock-based compensation and other	-1.5	0	-4.2	0	0	-0.8	3.5
Contributions from noncontrolling interest partners	107	0	22.5	0	0	84.5	0
Distributions to noncontrolling interest partners	-2.5	0	0	0	0	-2.5	0
Deconsolidation of subsidiary	-398.3	0	0	0.5	-6.1	-392.7	0
Deferred income taxes attributable to contributions from noncontrolling interest partners	-8.7	0	-8.7	0	0	0	0
2-for-1 forward stock split	0	1	-1	0	0	0	0
Balance at Sep. 30, 2013	$2,994.60	$2	$1,065.80	$1,978.70	($51.90)	$0	$0

Summary_of_Significant_Account

Summary of Significant Accounting Policies	9 Months Ended
Summary of Significant Accounting Policies	Sep. 30, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'
Summary of Significant Accounting Policies	'
	Summary of Significant Accounting Policies
	Organization

	The Company is an energy and energy services provider offering physical delivery and related services for both electricity and natural gas primarily in the south central United States. The Company conducts these activities through two business segments: (i) electric utility and (ii) natural gas midstream operations. For a discussion of the change in the Company’s business segments due to the formation of Enable Midstream Partners, see Note 12. For periods prior to May 1, 2013, the Company consolidated Enogex Holdings in its Condensed Consolidated Financial Statements. All significant intercompany transactions have been eliminated in consolidation.

	Effective May 1, 2013, OGE Energy, the ArcLight group and CenterPoint Energy, Inc., formed Enable Midstream Partners to own and operate the midstream businesses of OGE Energy and CenterPoint. In the formation transaction, OGE Energy and ArcLight contributed Enogex LLC to Enable Midstream Partners and the Company deconsolidated its previously held investment in Enogex Holdings and acquired an equity interest in Enable Midstream Partners. The Company determined that its contribution of Enogex LLC to Enable Midstream Partners met the requirements of being in substance real estate and was recorded at historical cost. The general partner of Enable Midstream Partners is equally controlled by CenterPoint and OGE Energy, who each have 50 percent of the management rights. Based on the 50/50 management ownership, with neither company having control, effective May 1, 2013, OGE Energy began accounting for its interest in Enable Midstream Partners using the equity method of accounting.

	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. OG&E is the largest electric utility in Oklahoma and its franchised service territory includes the Fort Smith, Arkansas area. OG&E sold its retail natural gas business in 1928 and is no longer engaged in the natural gas distribution business.


	As discussed below, the Company completed a 2-for-1 stock split of the Company's common stock effective July 1, 2013. All share and per share amounts within this Form 10-Q have been retroactively adjusted to reflect the effects of the stock split for all periods presented.
	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 September 30, 2013 and December 31, 2012, the results of its operations for the three and nine months ended September 30, 2013 and 2012 and the results of its cash flows for the nine months ended September 30, 2013 and 2012, have been included and are of a normal recurring nature except as otherwise disclosed.


	Due to seasonal fluctuations and other factors, the Company's operating results for the three and nine months ended September 30, 2013 are not necessarily indicative of the results that may be expected for the year ending December 31, 2013 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 2012 Form 10-K.
	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 actual or anticipated 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 actual or anticipated costs and obligations as regulatory assets or liabilities if it is probable, based on regulatory orders or other available evidence, that the cost or obligation 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 at:


	(In millions)	September 30, 2013			December 31, 2012
	Regulatory Assets
	Current
	Oklahoma demand program rider under recovery (A)	$	9.5		$	9.2
	Oklahoma demand program rider under recovery (A)	$	9.5		$	9.2
	Crossroads wind farm rider under recovery (A)	7.2			14.9
	Crossroads wind farm rider under recovery (A)	7.2			14.9
	Other (A)	6.8			2.9
	Other (A)	6.8			2.9
	Total Current Regulatory Assets	$	23.5		$	27
	Total Current Regulatory Assets	$	23.5		$	27
	Non-Current
	Non-Current
	Benefit obligations regulatory asset	$	350.1		$	370.6
	Benefit obligations regulatory asset	$	350.1		$	370.6
	Income taxes recoverable from customers, net	55.7			54.7
	Income taxes recoverable from customers, net	55.7			54.7
	Smart Grid	43.4			42.8
	Smart Grid	43.4			42.8
	Deferred storm expenses	18.3			12.7
	Deferred storm expenses	18.3			12.7
	Unamortized loss on reacquired debt	12.1			13
	Unamortized loss on reacquired debt	12.1			13
	Deferred pension expenses	1.9			4.5
	Deferred pension expenses	1.9			4.5
	Other	14.7			12.3
	Other	14.7			12.3
	Total Non-Current Regulatory Assets	$	496.2		$	510.6
	Total Non-Current Regulatory Assets	$	496.2		$	510.6
	Regulatory Liabilities
	Regulatory Liabilities
	Current
	Current
	Fuel clause over recoveries	$	12		$	109.2
	Fuel clause over recoveries	$	12		$	109.2
Smart Grid rider over recovery (B)	19.1			24.1
Smart Grid rider over recovery (B)	19.1			24.1
Other (B)	2.6			7.8
Other (B)	2.6			7.8
Total Current Regulatory Liabilities	$	33.7		$	141.1
Total Current Regulatory Liabilities	$	33.7		$	141.1
Non-Current
Non-Current
Accrued removal obligations, net	$	219.2		$	218.2
Accrued removal obligations, net	$	219.2		$	218.2
Pension tracker	14.2			9.2
Pension tracker	14.2			9.2
Deferred pension credits	9.3			17.7
Deferred pension credits	9.3			17.7
Total Non-Current Regulatory Liabilities	$	242.7		$	245.1
Total Non-Current Regulatory Liabilities	$	242.7		$	245.1

(A)	Included in Other Current Assets on the Condensed Consolidated Balance Sheets.

(B)	Included in Other Current Liabilities on the Condensed Consolidated Balance Sheets.
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, which could have significant financial effects.
Use of Estimates

In preparing the Condensed Consolidated Financial Statements, management is required to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and contingent liabilities at the date of the Condensed Consolidated Financial Statements and the reported amounts of revenues and expenses during the reporting period. Changes to these assumptions and estimates could have a material effect on the Company's Condensed Consolidated Financial Statements. However, the Company believes it has taken reasonable, but conservative, positions where assumptions and estimates are used in order to minimize the negative financial impact to the Company that could result if actual results vary from the assumptions and estimates. In management's opinion, the areas of the Company where the most significant judgment is exercised for all Company segments includes the determination of Pension Plan assumptions, impairment estimates of long-lived assets (including intangible assets), income taxes, contingency reserves, asset retirement obligations and the allowance for uncollectible accounts receivable. For the electric utility segment, the most significant judgment is also exercised in the valuation of regulatory assets and liabilities and unbilled revenues. For the natural gas midstream operations segment, the most significant judgment is also exercised in the valuation of operating revenues, natural gas purchases, purchase and sale contracts, assets and depreciable lives of property, plant and equipment, amortization methodologies related to intangible assets and impairment assessments of goodwill and equity method investments.
Investment in Unconsolidated Affiliate

OGE Energy's investment in Enable Midstream Partners 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, OGE Energy is not considered the primary beneficiary of Enable Midstream Partners since it does not have the power to direct the activities of Enable Midstream Partners that are considered most significant to the economic performance of Enable Midstream Partners. As discussed above, OGE Energy accounts for the investment in Enable Midstream Partners 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. OGE Energy's maximum exposure to loss related to Enable Midstream Partners is limited to OGE Energy's equity investment in Enable Midstream Partners as presented on the Company's Condensed Consolidated Balance Sheet at September 30, 2013. 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.

The Company considers distributions received from its unconsolidated affiliates which do not exceed cumulative equity in earnings subsequent to the date of investment to be a return on investment which are classified as operating activities in the Condensed Consolidated Statements of Cash Flows. The Company considers distributions received from its unconsolidated affiliates in excess of cumulative equity in earnings subsequent to the date of investment to be a return of investment which are classified as investing activities in the Condensed Consolidated Statements of Cash Flows.
Asset Retirement Obligation

The following table summarizes changes to the Company's asset retirement obligations during the nine months ended September 30, 2013 and 2012.


	Nine Months Ended
	September 30,
(In millions)	2013			2012
Balance at January 1	$	54		$	24.8
Balance at January 1	$	54		$	24.8
Liabilities settled (A)	(0.4		)	0.3
Liabilities settled (A)	(0.4		)	0.3
Accretion expense	1.7			1.6
Accretion expense	1.7			1.6
Revisions in estimated cash flows (B)	(0.7		)	26.7
Revisions in estimated cash flows (B)	(0.7		)	26.7
Balance at September 30	$	54.6		$	53.4
Balance at September 30	$	54.6		$	53.4

(A)	As a result of the formation of Enable Midstream Partners on May 1, 2013, the Company has no obligations at September 30, 2013 under OGE Holdings' asset retirement obligations previously disclosed in the Company's 2012 10-K.

(B)	Due to changes to OG&E's asset retirement obligations related to its wind farms as a result of changes in the assumption related to the timing of removal used in the valuation of the asset retirement obligations.
Accumulated Other Comprehensive Income (Loss)
The following table summarizes changes in the components of accumulated other comprehensive loss attributable to OGE Energy during the nine months ended September 30, 2013. All amounts below are presented net of tax and noncontrolling interest.


	Pension Plan and Restoration of Retirement Income Plan							Postretirement Benefit Plans
	Net loss			Prior service cost				Net loss			Prior service cost			Deferred commodity contracts hedging gains			Deferred interest rate swap hedging losses			Less: Noncontrolling interest			Total
Balance at December 31, 2012	$	(49.3	)	$	0.1			$	(15.7	)	$	7.2		$	0.1		$	(0.5	)	$	(9.0	)	$	(49.1	)
Balance at December 31, 2012	$	(49.3	)	$	0.1			$	(15.7	)	$	7.2		$	0.1		$	(0.5	)	$	(9.0	)	$	(49.1	)
Amounts reclassified from accumulated other comprehensive income (loss)	2.8			—				1.6			(1.4		)	0.2			0.2			0.1			3.3
	2.8			—				1.6			(1.4		)	0.2			0.2			0.1			3.3
Deconsolidation of Enogex Holdings	2.8			—				1			(0.3		)	(0.7		)	—			8.9			(6.1		)
Deconsolidation of Enogex Holdings	2.8			—				1			(0.3		)	(0.7		)	—			8.9			(6.1		)
Net current period other comprehensive income (loss)	5.6			—				2.6			(1.7		)	(0.5		)	0.2			9			(2.8		)
Net current period other comprehensive income (loss)	5.6			—				2.6			(1.7		)	(0.5		)	0.2			9			(2.8		)
Balance at September 30, 2013	$	(43.7	)	$	0.1			$	(13.1	)	$	5.5		$	(0.4	)	$	(0.3	)	$	—		$	(51.9	)
Balance at September 30, 2013	$	(43.7	)	$	0.1			$	(13.1	)	$	5.5		$	(0.4	)	$	(0.3	)	$	—		$	(51.9	)

The following table summarizes significant amounts reclassified out of accumulated other comprehensive loss by the respective line items in net income during the three and nine months ended September 30, 2013.


Details about Accumulated Other Comprehensive Loss Components	Amount Reclassified from Accumulated Other Comprehensive Income (Loss)						Affected Line Item in the Statement Where Net Income is Presented
	Three Months Ended			Nine Months Ended
	September 30, 2013			September 30, 2013
Gains (losses) on cash flow hedges
Commodity contracts	$	(0.6	)	$	(0.4	)	Cost of goods sold
Interest rate swap	(0.1		)	(0.3		)	Interest expense
	(0.7		)	(0.7		)	Total before tax
	(0.3		)	(0.3		)	Tax benefit
	$	(0.4	)	$	(0.4	)	Net of tax

Amortization of defined benefit pension items
Actuarial gains (losses)	$	(1.5	)	$	(4.6	)	(A)
Prior service cost	—			—			(A)
Prior service cost	—			—			(A)
	(1.5		)	(4.6		)	Total before tax
	(0.6		)	(1.8		)	Tax benefit
	(0.9		)	(2.8		)	Net of tax
	—			(0.1		)	Noncontrolling interest
	—			(0.1		)	Noncontrolling interest
	$	(0.9	)	$	(2.7	)	Net of tax and noncontrolling interest

Amortization of postretirement benefit plan items
Actuarial gains (losses)	$	(0.9	)	$	(2.5	)	(A)
Prior service cost	0.8			2.2			(A)
Prior service cost	0.8			2.2			(A)
	(0.1		)	(0.3		)	Total before tax
	—			(0.1		)	Tax benefit
	—			(0.1		)	Tax benefit
	$	(0.1	)	$	(0.2	)	Net of tax

Total reclassifications for the period	$	(1.4	)	$	(3.3	)	Net of tax and noncontrolling interest

(A)	These accumulated other comprehensive income (loss) components are included in the computation of net periodic benefit cost (see Note 11 for additional information).
Forward Stock Split

On May 16, 2013, the Company's Board of Directors approved a 2-for-1 forward stock split of the Company's common stock, effective July 1, 2013, which entitled each shareholder of record to receive two shares for every one share of Company stock owned by the shareholder. In connection with the stock split, an amendment to the Company's Articles of Incorporation was approved on May 16, 2013 which increased the number of authorized shares of common stock from 225 million to 450 million. All share and per share amounts within this Form 10-Q have been retroactively adjusted to reflect the effects of the stock split for all periods presented.
Reclassifications

As discussed in Note 12, the former natural gas transportation and storage segment and natural gas gathering and processing segment have been combined into the natural gas midstream operations segment and have been restated for all prior periods presented. Effective May 1, 2013, the Company deconsolidated its previously held investment in Enogex Holdings and acquired an equity interest in Enable Midstream Partners.

Accounting_Pronouncement

Accounting Pronouncement	9 Months Ended
Accounting Pronouncement	Sep. 30, 2013
New Accounting Pronouncements and Changes in Accounting Principles [Abstract]	'
New Accounting Pronouncements and Changes in Accounting Principles [Text Block]	'
	Accounting Pronouncement

	In July 2013, the Emerging Issues Task Force issued "Presentation of an Unrecognized Tax Benefit When a Net Operating Loss Carryforward or Tax Credit Carryforward Exists." The new standard requires entities to present an unrecognized tax benefit, or a portion of an unrecognized tax benefit, in the statement of financial position as a reduction to a deferred tax asset for a net operating loss carryforward or a tax credit carryforward, except as follows. To the extent that a net operating loss carryforward or tax credit carryforward at the reporting date is not available under the tax law of the applicable jurisdiction to settle any additional income taxes that would result from the disallowance of a tax position, the unrecognized tax benefit would be presented in the statement of financial position as a liability. The new standard is applicable for all entities that have unrecognized tax benefits when a net operating loss carryforward or a tax credit carryforward exists. The new standard is effective for interim and annual reporting periods beginning after December 15, 2013 and does not require any new financial statement disclosures. This new standard may be applied retrospectively or prospectively with early adoption permitted. The Company retrospectively adopted this new standard effective January 1, 2013.

Investment_in_Unconsolidated_A

Investment in Unconsolidated Affiliates	9 Months Ended
	Sep. 30, 2013
OGE Energy Midstream Partnership with CenterPoint Energy Inc. [Abstract]	'
Equity Method Investments and Joint Ventures Disclosure [Text Block]	'
	Investment in Unconsolidated Affiliates and Related Party Transactions

	On March 14, 2013, OGE Energy entered into a Master Formation Agreement with the ArcLight group and CenterPoint Energy, Inc., pursuant to which OGE Energy, the ArcLight Group and CenterPoint Energy, Inc., agreed to form Enable Midstream Partners to own and operate the midstream businesses of OGE Energy and CenterPoint that will initially be structured as a private limited partnership. This transaction closed on May 1, 2013.
	Pursuant to the Master Formation Agreement, OGE Energy and the ArcLight group indirectly contributed 100 percent of the equity interests in Enogex LLC to Enable Midstream Partners. The Company determined that its contribution of Enogex LLC to Enable Midstream Partners met the requirements of being in substance real estate and was recorded at historical cost. Enogex LLC is a provider of integrated natural gas midstream services. Enogex LLC is engaged in the business of gathering, processing, transporting and storing natural gas. Most of Enogex LLC's natural gas gathering, processing, transportation and storage assets are strategically located in the Arkoma and Anadarko basins of Oklahoma and the Texas Panhandle. CenterPoint Energy Field Services, LLC, a Delaware limited liability company and, prior to the closing of the transaction on May 1, 2013, a wholly owned subsidiary of CenterPoint, that provides natural gas gathering and processing services for certain natural gas fields in the Mid-continent region of the United States, was converted into a Delaware limited partnership that became Enable Midstream Partners. CenterPoint contributed to Enable Midstream Partners its equity interests in each of (i) CenterPoint Energy Gas Transmission Company, LLC, a Delaware limited liability company that is an interstate pipeline that provides natural gas transportation, storage and pipeline services to customers principally in Arkansas, Louisiana, Oklahoma and Texas, (ii) MRT, a Delaware limited liability company that is an interstate pipeline that provides natural gas transportation, storage and pipeline services to customers principally in Arkansas, Illinois and Missouri and (iii) certain of its other midstream subsidiaries and caused its subsidiary CenterPoint Energy Southeastern Pipelines Holding, LLC to contribute a 24.95 percent interest in Southeast Supply Header, LLC, a Delaware limited liability company. CenterPoint indirectly owned a 50 percent interest in Southeast Supply Header, LLC, which owns a 1.0 billion cubic feet per day, 274-mile interstate pipeline that runs from the Perryville Hub in Louisiana to Coden, Alabama.
	Immediately prior to closing, on May 1, 2013, the ArcLight group contributed $107.0 million and OGE Energy contributed $9.1 million to Enogex LLC in order to pay down short-term debt. At September 30, 2013, OGE Energy, through its wholly owned subsidiary OGE Holdings, holds 28.5 percent of the limited partners interests in Enable Midstream Partners.

	CenterPoint has certain put rights, and Enable Midstream Partners has certain call rights, exercisable with respect to any interest in Southeast Supply Header, LLC retained by CenterPoint following the formation of Enable Midstream Partners, under which CenterPoint would contribute to Enable Midstream Partners CenterPoint's retained interest in Southeast Supply Header, LLC at a price equal to the fair market value of such interest at the time the put right or call right is exercised. If CenterPoint were to exercise such put right or Enable Midstream Partners were to exercise such call right, CenterPoint's retained interest in Southeast Supply Header, LLC would be contributed to Enable Midstream Partners in exchange for consideration consisting of a specified number of limited partnership units and, subject to certain restrictions, a cash payment, payable either from CenterPoint to Enable Midstream Partners or from Enable Midstream Partners to CenterPoint, in an amount such that the total consideration exchanged is equal in value to the fair market value of the contributed interest in Southeast Supply Header, LLC.

	The general partner of Enable Midstream Partners is equally controlled by CenterPoint and OGE Energy, who each have 50 percent of the management rights. CenterPoint and OGE Energy also own a 40 percent and 60 percent interest, respectively, in any incentive distribution rights to be held by the general partner of Enable Midstream Partners following an initial public offering of Enable Midstream Partners. In addition, for a period of time, the ArcLight group will have certain protective rights and approval rights over certain material activities of Enable Midstream Partners, including material increases in capital expenditures and certain equity issuances, entering into transactions with related parties and acquiring, pledging or disposing of certain material assets. The general partner of Enable Midstream Partners will initially be governed by a board made up of an equal number of representatives designated by each of CenterPoint Energy, Inc. and OGE Energy. Based on the 50/50 management ownership, with neither company having control, effective May 1, 2013, OGE Energy deconsolidated its interest in Enogex Holdings LLC and began accounting for its interest in Enable Midstream Partners using the equity method of accounting.

	Pursuant to a Registration Rights Agreement dated as of May 1, 2013, OGE Energy and CenterPoint Energy, Inc. agreed to initiate the process for the sale of an equity interest in Enable Midstream Partners in an initial public offering. Enable Midstream Partners has agreed to file a registration statement for the initial public offering no later than May 1, 2014 and, subject to limited exceptions, consummate the initial public offering within 180 days of the filing of the registration statement. The Company currently expects that Enable Midstream Partners will file a registration statement during the fourth quarter of 2013. The initial public offering is subject to market conditions and OGE Energy can give no assurances that the initial public offering will be consummated.

	Effective May 1, 2013, Enable Midstream Partners entered into a $1.4 billion, five-year senior unsecured revolving credit facility in accordance with the terms of the Master Formation Agreement and Enogex LLC's $400 million revolving credit facility was terminated.


	Subject to the exceptions provided below, pursuant to the terms of an Omnibus Agreement dated as of May 1, 2013 among OGE Energy, the ArcLight group and CenterPoint Energy, Inc., each of OGE Energy and CenterPoint Energy, Inc. will be required to hold or otherwise conduct all of its respective Midstream Operations (as defined below) located within the United States in Enable Midstream Partners. This restriction will cease to apply to both OGE Energy and CenterPoint Energy, Inc. as soon as either OGE Energy or CenterPoint Energy, Inc. ceases to hold (i) any interest in the general partner of Enable Midstream Partners or (ii) at least 20 percent of the limited partner interests of Enable Midstream Partners. "Midstream Operations" generally means, subject to certain exceptions, the gathering, compression, treatment, processing, blending, transportation, storage, isomerization and fractionation of crude oil and natural gas, its associated production water and enhanced recovery materials such as carbon dioxide, and its respective constituents and the following products: methane, NGLs (Y-grade, ethane, propane, normal butane, isobutane and natural gasoline), condensate, and refined products and distillates (gasoline, refined product blendstocks, olefins, naphtha, aviation fuels, diesel, heating oil, kerosene, jet fuels, fuel oil, residual fuel oil, heavy oil, bunker fuel, cokes, and asphalts), to the extent such activities are located within the United States.
	In addition, if OGE Energy or CenterPoint Energy, Inc. acquires any assets or equity of any person engaged in Midstream Operations with a value in excess of $50 million (or $100 million in the aggregate with such party's other acquired Midstream Operations that have not been offered to Enable Midstream Partners), the acquiring party will be required to offer Enable Midstream Partners the opportunity to acquire such assets or equity for such value; provided, that the acquiring party will not be obligated to offer any such assets or equity to Enable Midstream Partners if the acquiring party intends to cease using them in Midstream Operations within 12 months. If Enable Midstream Partners does not exercise its option, then the acquiring party will be free to retain and operate such Midstream Operations; provided, however, that if the fair market value of such Midstream Operations is greater than 66 2/3 percent of the fair market value of all of the assets being acquired in such transaction, then the acquiring party will be required to dispose of such Midstream Operations within 24 months.
	As long as the ArcLight group has certain protective rights, the ArcLight group will be prohibited from pursuing any transaction independently from Enable Midstream Partners (i) if the ArcLight group's consent is required for Enable Midstream Partners to pursue such transaction and (ii) the ArcLight group affirmatively votes not to consent to such transaction.

	On May 1, 2013, OGE Energy, OGE Holdings and Enable Midstream Partners entered into a Seconding Agreement. During the term of the Seconding Agreement, OGE Holdings' employees will continue to perform services for Enable Midstream Partners and its subsidiaries.

	Distributions received from Enable Midstream Partners were $17.4 million during the three and nine months ended September 30, 2013.

	Related Party Transactions


	As OGE Energy's interest in Enogex Holdings was deconsolidated on May 1, 2013, operating costs charged and related party transactions between the Company and its affiliate, Enable Midstream Partners, after May 1, 2013, which were previously eliminated in consolidation, are discussed below.

	OGE Energy charged operating costs to Enogex Holdings/Enable Midstream Partners of $6.6 million and $10.9 million during the three and five months ended September 30, 2013, respectively. OGE Energy charges operating costs to its subsidiaries and unconsolidated affiliates based on several factors. Operating costs directly related to specific subsidiaries and unconsolidated affiliates are assigned to those subsidiaries and unconsolidated affiliates. Where more than one subsidiary or unconsolidated affiliate benefits from certain expenditures, the costs are shared between those subsidiaries and unconsolidated affiliates receiving the benefits. Operating costs incurred for the benefit of all subsidiaries and unconsolidated affiliates are allocated among the subsidiaries and unconsolidated affiliates, either as overhead based primarily on labor costs or using the "Distrigas" method. The Distrigas method is a three-factor formula that uses an equal weighting of payroll, net operating revenues and gross property, plant and equipment. OGE Energy adopted the Distrigas method in January 1996 as a result of a recommendation by the OCC Staff. OGE Energy believes this method provides a reasonable basis for allocating common expenses.


	Related Party Transactions with Enable Midstream Partners


		Three Months Ended			Five Months Ended
		September 30,			September 30,
	(In millions)	2013			2013
	Operating Revenues:
	Electricity to power electric compression assets	$	3.9		$	5.2

	Cost of Goods Sold:
	Natural gas transportation services	$	8.7		$	14.5

	Natural gas storage services	3.1			5.4

	Natural gas purchases (A)	9.4			11.9


	(A)	At September 30, 2013, there was $1.4 million of natural gas purchases recorded for these activities.

	Summarized Financial Information of Enable Midstream Partners

	As Enable Midstream Partners began operations on May 1, 2013, summarized unaudited financial information for 100 percent of Enable Midstream Partners is presented below at September 30, 2013 and for the three and five months ended September 30, 2013.


	Balance Sheet	September 30, 2013
		(In millions)
	Current assets	$	427.5

	Non-current assets	10,537.10

	Current liabilities	622.1

Non-current liabilities	2,140.40



	Three Months Ended			Five Months Ended
Income Statement	30-Sep-13			30-Sep-13
	(In millions)
Operating revenues	$	796.4		$	1,298.40

Gross margin	337.1			544.5

Operating income	132			206.7

Net income	123.3			188.4


Enable Midstream Partners concluded that the formation of Enable Midstream Partners was considered a business combination, and CenterPoint Midstream was the acquirer of Enogex Holdings for accounting purposes. Under this method, the fair value of the consideration paid by CenterPoint Midstream for Enogex Holdings is allocated to the assets acquired and liabilities assumed on May 1, 2013 based on their fair value. Enogex Holdings' assets, liabilities and equity have accordingly been adjusted to estimated fair value as of May 1, 2013, resulting in an increase to equity of $2.2 billion. Determining the fair value of certain assets and liabilities assumed is judgmental in nature and often involves the use of significant estimates and assumptions. Enable Midstream Partners utilized appraisers to assist in the determination of fair value of certain assets.

OGE Energy recorded equity in earnings of unconsolidated affiliates of $46.0 million, and $64.5 million for the three and five months ended September 30, 2013, respectively. Equity in earnings of unconsolidated affiliates includes OGE Energy's 28.5 percent share of Enable Midstream Partners earnings adjusted for the amortization of the basis difference of OGE Energy's original investment in Enogex and its underlying equity in net assets of Enable Midstream, based on historical cost as of May 1, 2013. The basis difference is being amortized over approximately 30 years, the average life of the assets to which the basis difference is attributed. Equity in earnings of unconsolidated affiliates is also adjusted for the elimination of the Enogex Holdings fair value adjustments described above.



	Three Months Ended			Five Months Ended
Reconciliation of Equity in Earnings of Unconsolidated Affiliates	30-Sep-13			30-Sep-13
	(In millions)
OGE's 28.5% share of Enable Net Income	$	35.1		$	53.6

Amortization of basis difference	5.9			5.9

Elimination of Enogex Holdings fair value adjustments	5			5

OGE's Equity in earnings of unconsolidated affiliates	$	46		$	64.5

Fair_Value_Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2013
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 and examples of each 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. Instruments classified as Level 1 include natural gas futures, swaps and options transactions for contracts traded on the NYMEX and settled through a NYMEX clearing broker.

	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. Instruments classified as Level 2 include over-the-counter NYMEX natural gas swaps, natural gas basis swaps and natural gas purchase and sales transactions in markets such that the pricing is closely related to the NYMEX pricing.

	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 utilizes the market approach in determining the fair value of its derivative positions by using either NYMEX published market prices, independent broker pricing data or broker/dealer valuations. The valuations of derivatives with pricing based on NYMEX published market prices may be considered Level 1 if they are settled through a NYMEX clearing broker account with daily margining. Over-the-counter derivatives with NYMEX based prices are considered Level 2 due to the impact of counterparty credit risk. Valuations based on independent broker pricing or broker/dealer valuations may be classified as Level 2 only to the extent they may be validated by an additional source of independent market data for an identical or closely related active market. In certain less liquid markets or for longer-term contracts, forward prices are not as readily available. In these circumstances, contracts are valued using internally developed methodologies that consider historical relationships among various quoted prices in active markets that result in management's best estimate of fair value. These contracts are classified as Level 3.

	The impact to the fair value of derivatives due to credit risk is calculated using the probability of default based on Standard & Poor's Ratings Services and/or internally generated ratings. The fair value of derivative assets is adjusted for credit risk. The fair value of derivative liabilities is adjusted for credit risk only if the impact is deemed material.

	Contracts with Master Netting Arrangements

	Fair value amounts recognized for forward, interest rate swap, option and other conditional or exchange contracts executed with the same counterparty under a master netting arrangement may be offset. The reporting entity's choice to offset or not must be applied consistently. A master netting arrangement exists if the reporting entity has multiple contracts, whether for the same type of conditional or exchange contract or for different types of contracts, with a single counterparty that are subject to a contractual agreement that provides for the net settlement of all contracts through a single payment in a single currency in the event of default on or termination of any one contract. Offsetting the fair values recognized for forward, interest rate swap, option and other conditional or exchange contracts outstanding with a single counterparty results in the net fair value of the transactions being reported as an asset or a liability in the Condensed Consolidated Balance Sheets. The Company has presented the fair values of its derivative contracts under master netting agreements using a net fair value presentation.

	The Company had no material financial instruments measured at fair value on a recurring basis at September 30, 2013. The following table summarizes the Company's assets and liabilities that are measured at fair value on a recurring basis at December 31, 2012 as well as presents the Company's commodity contracts fair value included in the Company's Condensed Consolidated Balance Sheet at December 31, 2012. The Company adopted the FASB's accounting guidance requiring additional disclosures for balance sheet offsetting of assets and liabilities effective January 1, 2013. The Company posted $0.2 million of collateral at December 31, 2012 which has been included within netting adjustments in the table below. The Company held no collateral at December 31, 2012. The Company has offset all amounts subject to master netting agreements in the Company's Condensed Consolidated Balance Sheet at December 31, 2012. The Company held no Level 3 investments at December 31, 2012.


	December 31, 2012
	(In millions)	Commodity Contracts						Gas Imbalances (A)
		Assets			Liabilities			Assets (B)		Liabilities (C)
	Quoted market prices in active market for identical assets (Level 1)	$	5		$	5		$	—	$	—

	Significant other observable inputs (Level 2)	0.5			0.5			3.1		3.8

	Total fair value	5.5			5.5			3.1		3.8

	Netting adjustments	(5.0		)	(5.2		)	—		—

	Total	$	0.5		$	0.3		$	3.1	$	3.8


	(A)	The Company uses the market approach to fair value its gas imbalance assets and liabilities, using an average of the Inside FERC Gas Market Report for Panhandle Eastern Pipe Line Co. (Texas, Oklahoma Mainline), ONEOK (Oklahoma) and ANR Pipeline (Oklahoma) indices.

	(B)	Gas imbalance assets exclude fuel reserves for under retained fuel due from shippers of $5.9 million at December 31, 2012, which fuel reserves are based on the value of natural gas at the time the imbalance was created and which are not subject to revaluation at fair market value.

	(C)	Gas imbalance liabilities exclude fuel reserves for over retained fuel due to shippers of $1.2 million at December 31, 2012, which fuel reserves are based on the value of natural gas at the time the imbalance was created and which are not subject to revaluation at fair market value.
	The following table summarizes the fair value and carrying amount of the Company's financial instruments at September 30, 2013 and December 31, 2012.


		September 30, 2013						December 31, 2012
	(In millions)	Carrying Amount			Fair			Carrying Amount		Fair
					Value					Value
	Long-Term Debt
	OG&E Senior Notes	$	2,154.30		$	2,455.20		$	1,904.20	$	2,401.60

	OG&E Industrial Authority Bonds	135.4			135.4			135.4		135.4

	OG&E Tinker Debt	10.4			9.1			10.7		10

	OGE Energy Senior Notes	99.9			103.7			99.9		106.3

	Enogex LLC Senior Notes	(A)			(A)			448.4		493.4

	Enogex LLC Term Loan	(A)			(A)			250		250


	(A)	As a result of the formation of Enable Midstream Partners on May 1, 2013 and the Company's deconsolidation of Enogex Holdings, the Company's consolidated financial statements do not include any obligations for the Enogex LLC Senior Notes and Enogex LLC Term Loan as of May 1, 2013.

	The Company's long-term debt is valued at the carrying amount. The fair value of the Company's long-term debt is based on quoted market prices and estimates of current rates available for similar issues with similar maturities and is classified as Level 2 in the fair value hierarchy except for the Tinker Debt which fair value was based on calculating the net present value of the monthly payments discounted by the Company's current borrowing rate and is classified as Level 3 in the fair value hierarchy.

Derivative_Instruments_and_Hed

Derivative Instruments and Hedging Activities	9 Months Ended
	Sep. 30, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Derivative Instruments and Hedging Activities	'
	Derivative Instruments and Hedging Activities
	The Company is exposed to certain risks relating to its ongoing business operations. The primary risk managed using derivatives instruments is interest rate risk. The Company is also exposed to credit risk in its business operations.

	Interest Rate Risk

	The Company's exposure to changes in interest rates primarily relates to short-term variable-rate debt and commercial paper. The Company manages its interest rate exposure by monitoring and limiting the effects of market changes in interest rates. The Company utilizes interest rate derivatives to alter interest rate exposure in an attempt to reduce the effects of these changes. Interest rate derivatives are used solely to modify interest rate exposure and not to modify the overall leverage of the debt portfolio.

	Credit Risk

	The Company is exposed to certain credit risks relating to its ongoing business operations. Credit risk includes the risk that counterparties that owe the Company money or energy will breach their obligations. If the counterparties to these arrangements fail to perform, the Company may be forced to enter into alternative arrangements. In that event, the Company's financial results could be adversely affected and the Company could incur losses.

	Cash Flow Hedges

	For derivatives that are designated and qualify as a cash flow hedge, the effective portion of the change in fair value of the derivative instrument is reported as a component of Accumulated Other Comprehensive Income (Loss) and recognized into earnings in the same period during which the hedged transaction affects earnings. The ineffective portion of a derivative's change in fair value or hedge components excluded from the assessment of effectiveness is recognized currently in earnings. The Company measures the ineffectiveness of commodity cash flow hedges using the change in fair value method whereby the change in the expected future cash flows designated as the hedge transaction are compared to the change in fair value of the hedging instrument. Forecasted transactions, which are designated as the hedged transaction in a cash flow hedge, are regularly evaluated to assess whether they continue to be probable of occurring. If the forecasted transactions are no longer probable of occurring, hedge accounting will cease on a prospective basis and all future changes in the fair value of the derivative will be recognized directly in earnings.

	The Company previously designated as cash flow hedges derivatives for OGE Holdings' NGLs volumes and corresponding keep-whole natural gas resulting from its natural gas processing contracts (processing hedges) and natural gas positions resulting from its natural gas gathering and processing operations and natural gas transportation and storage operations (operational gas hedges). The Company also previously designated as cash flow hedges certain derivatives for certain natural gas storage inventory positions. Due to the deconsolidation effective May 1, 2013, the Company had no material instruments designated as cash flow hedges at September 30, 2013.

	Fair Value Hedges

	For derivative instruments that are designated and qualify as a fair value hedge, the gain or loss on the derivative as well as the offsetting loss or gain on the hedged item attributable to the hedge risk are recognized currently in earnings. The Company includes the gain or loss on the hedged items in Operating Revenues as the offsetting loss or gain on the related hedging derivative.

	At September 30, 2013 and December 31, 2012, the Company had no derivative instruments that were designated as fair value hedges.

	Derivatives Not Designated as Hedging Instruments

	Derivative instruments not designated as hedging instruments are utilized in OGE Holdings' asset management activities. For derivative instruments not designated as hedging instruments, the gain or loss on the derivative is recognized currently in earnings.

	At September 30, 2013 and December 31, 2012, the Company had no material derivative instruments that were not designated as hedging instruments.

	Balance Sheet Presentation Related to Derivative Instruments

	The Company had no material derivative instruments included in its Condensed Consolidated Balance Sheet at September 30, 2013. The fair value of the derivative instruments that are presented in the Company's Condensed Consolidated Balance Sheet at December 31, 2012 are as follows:


			Fair Value
	Instrument	Balance Sheet Location	Assets			Liabilities
			(In millions)
	Derivatives Designated as Hedging Instruments
	Natural Gas
	Financial Futures/Swaps	Other Current Assets	$	—		$	0.5

	Total		$	—		$	0.5


	Derivatives Not Designated as Hedging Instruments
	Natural Gas
	Financial Futures/Swaps	Current PRM	$	0.1		$	—

		Other Current Assets	5			4.7

	Physical Purchases/Sales	Current PRM	0.4			0.3

	Total		$	5.5		$	5

	Total Gross Derivatives (A)		$	5.5		$	5.5


	(A)	See Note 4 for a reconciliation of the Company's total derivatives fair value to the Company's Condensed Consolidated Balance Sheet at December 31, 2012.

	Income Statement Presentation Related to Derivative Instruments

	The following tables present the effect of derivative instruments on the Company's Condensed Consolidated Statement of Income for the three months ended September 30, 2012.

Derivatives in Cash Flow Hedging Relationships


(In millions)	Amount Recognized in Other Comprehensive Income			Amount Reclassified from Accumulated Other Comprehensive Income (Loss) into Income

							Amount Recognized in Income
Natural Gas Financial Futures/Swaps	$	(0.8	)	$	—		$	—

Interest Rate Swap	—			(0.1		)	—

Total	$	(0.8	)	$	(0.1	)	$	—


Derivatives Not Designated as Hedging Instruments



(In millions)	Amount Recognized in Income
Natural Gas Physical Purchases/Sales	$	(2.7	)
Natural Gas Financial Futures/Swaps	(0.2		)
Total	$	(2.9	)

The following tables present the effect of derivative instruments on the Company's Condensed Consolidated Statement of Income for the nine months ended September 30, 2012.

Derivatives in Cash Flow Hedging Relationships


(In millions)	Amount Recognized in Other Comprehensive Income			Amount Reclassified from Accumulated Other Comprehensive Income (Loss) into Income

							Amount Recognized in Income
Natural Gas Financial Futures/Swaps	$	(1.0	)	$	5.2		$	—

Interest Rate Swap	—			(0.3		)	—

Total	$	(1.0	)	$	4.9		$	—


Derivatives Not Designated as Hedging Instruments


(In millions)	Amount Recognized in Income
Natural Gas Physical Purchases/Sales	$	(8.8	)
Natural Gas Financial Futures/Swaps	0.8

Total	$	(8.0	)

For derivatives designated as cash flow hedges in the tables above, amounts reclassified from Accumulated Other Comprehensive Income (Loss) into income (effective portion) and amounts recognized in income (ineffective portion) for the three and nine months ended September 30, 2012, if any, are reported in Operating Revenues. For derivatives not designated as hedges in the tables above, amounts recognized in income for the three and nine months ended September 30, 2012, if any, are reported in Operating Revenues.

Credit-Risk Related Contingent Features in Derivative Instruments

At September 30, 2013 the Company had no derivative instruments that contain credit-risk related contingent features.

StockBased_Compensation

Stock-Based Compensation	9 Months Ended
	Sep. 30, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Disclosure of Compensation Related Costs, Share-based Payments [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 nine months ended September 30, 2013 and 2012 related to the Company's performance units and restricted stock.


		Three Months Ended				Nine Months Ended
		September 30,				September 30,
	(In millions)	2013		2012		2013		2012
	Performance units
	Total shareholder return	$	2.5	$	1.9	$	6.4	$	5.7

	Earnings per share	0.6		0.7		1.9		2

	Total performance units	3.1		2.6		8.3		7.7

	Restricted stock	0.1		0.1		0.3		0.5

	Total compensation expense	3.2		2.7		8.6		8.2

	Less: Amount paid by unconsolidated affiliates	1.4		—		2		—

	Net compensation expense	$	1.8	$	2.7	$	6.6	$	8.2

	Income tax benefit	$	0.7	$	1	$	2.6	$	3.2


	The Company has issued new shares to satisfy stock option exercises, restricted stock grants and payouts of earned performance units. During the three and nine months ended September 30, 2013, there were 292 shares forfeited and 549,228 shares of new common stock issued, respectively, pursuant to the Company's stock incentive plans related to exercised stock options, restricted stock grants (net of forfeitures) and payouts of earned performance units. During the nine months ended September 30, 2013, there were 125,264 of treasury stock shares issued. During the three and nine months ended September 30, 2013, there were 4,038 shares and 10,512 shares of restricted stock, respectively, returned to the Company to satisfy tax liabilities. The Company received $1.4 million during the nine months ended September 30, 2013 related to exercised stock options. The Company did not realize an income tax benefit for the tax deductions from the exercised stock options during the three and nine months ended September 30, 2013 due to the Company being in a tax net operating loss position in 2013.

	As a result of the formation of Enable Midstream Partners on May 1, 2013, 50 percent of OGE Holdings' 2013 performance unit grants that were previously based on earnings before interest, taxes, depreciation and amortization were converted to stock-based compensation. The performance unit grants converted totaled 91,390, which is comprised of 45,596 total shareholder return performance units with a $25.89 grant date fair value and 45,794 earnings per share performance units with a $26.73 grant date fair value. As a result of a modification to the 2012 performance unit grants, 50 percent of OGE Holdings' 2012 performance unit grants that were previously based on earnings before interest, taxes and depreciation and amortization were converted to stock-based compensation. The performance unit grants converted totaled 82,400 , which is comprised of 41,288 total shareholder return performance units with a $47.71 grant date fair value and 41,112 earnings per share performance units with a $34.94 grant date fair value. The amount of these performance units were adjusted for the effects of the stock split. The impact of the modification of the performance unit grants on stock-based compensation expense for the three and nine months ended September 30, 2013 was not material.

Income_Taxes

Income Taxes	9 Months Ended
Income Taxes	Sep. 30, 2013
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 examinations by tax authorities for years prior to 2010 or state and local tax examinations by tax authorities for years prior to 2005. 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 are being amortized to income over the life of the related property. OG&E continues to amortize its Federal investment tax credits on a ratable basis throughout the year. OG&E earns both Federal and Oklahoma state tax credits associated with production from its wind farms and earns Oklahoma state tax credits associated with its investments in electric generating facilities which further reduce the Company's effective tax rate.


	As previously reported in the Company's 2012 Form 10-K, in January 2013, OG&E determined that a portion of certain Oklahoma investment tax credits previously recognized but not yet utilized may not be available for utilization in future years. During the first quarter of 2013, OG&E recorded a reserve of $7.8 million ($5.1 million after tax) related to a portion of the Oklahoma investment tax credits generated in years prior to 2013 but not yet utilized due to management's determination that it is more likely than not that it will be unable to utilize these credits.



	As a result of acquiring an equity interest in Enable Midstream Partners, the Company has a lower effective tax rate in conjunction with the formation of Enable Midstream Partners in states with lower state tax rates, which reduced income tax expense for the nine months ended September 30, 2013 by $3.9 million. In addition, deferred tax adjustments related to the Company's deconsolidation of Enogex Holdings increased income tax expense for the nine months ended September 30, 2013 by $3.9 million.

	Acquisition of the equity interest in Enable Midstream Partners on May 1, 2013, is also expected to increase the Company's utilization of net operating loss carryforwards throughout 2013. The Company now projects utilization of approximately $122.0 million of Federal net operating loss carryforwards in 2013. State net operating loss utilization is expected to begin in 2014.

	In the third quarter of 2013, the Company recognized a $17.1 million reduction in deferred state income taxes, associated with a remeasurement of the accumulated deferred taxes related to the formation of Enable Midstream Partners, LP.

Common_Equity

Common Equity	9 Months Ended
	Sep. 30, 2013
Common Equity [Text Block]	'
	Common Equity

	Forward Stock Split

	On May 16, 2013, the Company's Board of Directors approved a 2-for-1 forward stock split of the Company's common stock, effective July 1, 2013, which entitled each shareholder of record to receive two shares for every one share of Company stock owned by the shareholder. In connection with the stock split, an amendment to the Company's Articles of Incorporation was approved on May 16, 2013 which increased the number of authorized shares of common stock from 225 million to 450 million. All share and per share amounts within this Form 10-Q have been retroactively adjusted to reflect the effects of the stock split for all periods presented.

	Automatic Dividend Reinvestment and Stock Purchase Plan

	The Company issued 105,595 shares and 304,385 shares, respectively, of common stock under its Automatic Dividend Reinvestment and Stock Purchase Plan during the three and nine months ended September 30, 2013 and received proceeds of $4.0 million and $10.4 million, respectively. The Company may, from time to time, issue additional shares under its Automatic Dividend Reinvestment and Stock Purchase Plan to fund capital requirements or working capital needs. At September 30, 2013, there were 3,940,603 shares of unissued common stock reserved for issuance under the Company's Automatic Dividend Reinvestment and Stock Purchase Plan.

	Earnings Per Share

	Basic earnings per share is calculated by dividing net income attributable to OGE Energy by the weighted average number of the Company's common shares outstanding during the period. In the calculation of diluted earnings 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. Basic and diluted earnings per share for the Company were calculated as follows:


		Three Months Ended				Nine Months Ended
		September 30,				September 30,
	(In millions)	2013		2012		2013		2012
	Net Income Attributable to OGE Energy	$	215.2	$	185.5	$	330	$	316.5

	Average Common Shares Outstanding
	Basic average common shares outstanding	198.4		197.4		198.1		197

	Effect of dilutive securities:
	Contingently issuable shares (performance units)	1.3		0.9		1.2		0.9

	Diluted average common shares outstanding	199.7		198.3		199.3		197.9

	Basic Earnings Per Average Common Share Attributable to OGE Energy Common Shareholders	$	1.08	$	0.94	$	1.67	$	1.61

	Diluted Earnings Per Average Common Share Attributable to OGE Energy Common Shareholders	$	1.08	$	0.94	$	1.66	$	1.6

	Anti-dilutive shares excluded from earnings per share calculation	—		—		—		—

LongTerm_Debt

Long-Term Debt	9 Months Ended
	Sep. 30, 2013
Long-term Debt, Unclassified [Abstract]	'
Long-Term Debt	'
	Long-Term Debt

	At September 30, 2013, 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 as follows:


	SERIES			DATE DUE	AMOUNT
					(In millions)
	0.18%	-	0.34%	Garfield Industrial Authority, January 1, 2025	$	47

	0.12%	-	0.39%	Muskogee Industrial Authority, January 1, 2025	32.4

	0.11%	-	0.30%	Muskogee Industrial Authority, June 1, 2027	56

	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 Financial Statements. OG&E believes that it has sufficient liquidity to meet these obligations.

	Issuance of Long-Term Debt


	On May 8, 2013, OG&E issued $250 million of 3.9% senior notes due May 1, 2043. The proceeds from the issuance were added to OG&E's general funds and were used to repay short-term debt, fund capital expenditures, general corporate expenses and for working capital purposes. OG&E expects to issue additional long-term debt from time to time when market conditions are favorable and when the need arises.

ShortTerm_Debt_and_Credit_Faci

Short-Term Debt and Credit Facilities

9 Months Ended

Sep. 30, 2013

Short-term Debt [Abstract]

Short-Term Debt and Credit Facilities

Short-Term Debt and Credit Facilities

The Company borrows on a short-term basis, as necessary, by the issuance of commercial paper and by borrowings under its revolving credit agreements. The short-term debt balance was $447.0 million and $430.9 million at September 30, 2013 and December 31, 2012, respectively. The following table provides information regarding the Company's revolving credit agreements at September 30, 2013.

Aggregate

Amount

Weighted-Average

Entity

Commitment

Outstanding (A)

Interest Rate

Maturity

(In millions)

OGE Energy (B)

750

447

0.3

(E)

13-Dec-17

(F)

OG&E (C)

400

2.1

0.53

(E)

13-Dec-17

(F)

Total

1,150.00

(D)

449.1

0.3

(A)

Includes direct borrowings under the revolving credit agreements, commercial paper borrowings and letters of credit at September 30, 2013.

(B)

This bank facility is available to back up OGE Energy's commercial paper borrowings and to provide revolving credit borrowings. This bank facility can also be used as a letter of credit facility.

(C)

This bank facility is available to back up OG&E's commercial paper borrowings and to provide revolving credit borrowings. This bank facility can also be used as a letter of credit facility.

(D)

Effective May 1, 2013, Enable Midstream Partners entered into a $1.4 billion, five-year senior unsecured revolving credit facility in accordance with the terms of the Master Formation Agreement and Enogex LLC's $400 million revolving credit facility was terminated.

(E)

Represents the weighted-average interest rate for the outstanding borrowings under the revolving credit agreements, commercial paper borrowings and letters of credit.

(F)

In December 2011, the Company and OG&E entered into unsecured five-year revolving credit agreements to total in the aggregate $1,150.0 million ($750 million for the Company and $400 million for OG&E). Each of the credit facilities contain an option, which may be exercised up to two times, to extend the term for an additional year, subject to consent of a specified percentage of the lenders. Effective July 29, 2013, the Company and OG&E utilized one of these one-year extensions, and received consent from all of the lenders, to extend the maturity of their credit agreements to December 13, 2017.

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 ratings 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 cash collateral or letters of credit.

OG&E must obtain regulatory approval from the FERC in order to borrow on a short-term basis. OG&E has the necessary regulatory approvals to incur up to $800 million in short-term borrowings at any one time for a two-year period beginning January 1, 2013 and ending December 31, 2014.

Retirement_Plans_and_Postretir

Retirement Plans and Postretirement Benefit Plans	9 Months Ended
	Sep. 30, 2013
Retirement Plans and Postretirement Benefit Plans [Abstract]	'
Pension and Other Postretirement Benefits Disclosure [Text Block]	'
	Retirement Plans and Postretirement Benefit Plans

	The details of net periodic benefit cost of the Company's Pension Plan, the Restoration of Retirement Income Plan and the postretirement benefit plans included in the Condensed Consolidated Financial Statements are as follows:

	Net Periodic Benefit Cost


		Pension Plan												Restoration of Retirement
														Income Plan
		Three Months						Nine Months						Three Months				Nine Months
		Ended						Ended						Ended				Ended
		September 30,						September 30,						September 30,				September 30,
	(In millions)	2013 (B)			2012 (B)			2013 (C)			2012 (C)			2013 (B)		2012 (B)		2013 (C)		2012 (C)
	Service cost	$	4.8		$	4.5		$	14.3		$	13.5		$	0.3	$	0.3	$	0.9	$	0.8

	Interest cost	6.6			7.5			20			22.5			0.1		0.1		0.4		0.4

	Expected return on plan assets	(12.1		)	(11.5		)	(36.3		)	(34.5		)	—		—		—		—

	Amortization of net loss	6.6			6			19.8			17.9			0.1		0.1		0.3		0.3

	Amortization of unrecognized prior service cost (A)	0.5			0.5			1.4			1.6			0.1		0.2		0.2		0.5

	Total net periodic benefit cost	6.4			7			19.2			21			0.6		0.7		1.8		2

	Less: Amount paid by unconsolidated affiliates	1.5			—			2.5			—			0.1		—		0.1		—

	Net periodic benefit cost (net of unconsolidated affiliates)	$	4.9		$	7		$	16.7		$	21		$	0.5	$	0.7	$	1.7	$	2


	(A)	Unamortized prior service cost is amortized on a straight-line basis over the average remaining service period to the first eligibility age of participants who are expected to receive a benefit and are active at the date of the plan amendment.

	(B)	In addition to the $5.4 million and $7.7 million of net periodic benefit cost recognized during the three months ended September 30, 2013 and 2012, respectively, OG&E recognized an increase in pension expense during the three months ended September 30, 2013 and 2012 of $1.5 million and $1.9 million, respectively, to maintain the allowable amount to be recovered for pension expense in the Oklahoma jurisdiction which are included in the Pension tracker regulatory liability (see Note 1).

	(C)	In addition to the $18.4 million and $23.0 million of net periodic benefit cost recognized during the nine months ended September 30, 2013 and 2012, respectively, OG&E recognized an increase in pension expense during the nine months ended September 30, 2013 and 2012 of $4.6 million and $7.6 million, respectively, to maintain the allowable amount to be recovered for pension expense in the Oklahoma jurisdiction which are included in the Pension tracker regulatory liability (see Note 1).


		Postretirement Benefit Plans
		Three Months						Nine Months
		Ended						Ended
		September 30,						September 30,
	(In millions)	2013 (B)			2012 (B)			2013 (C)			2012 (C)
	Service cost	$	1.1		$	1		$	3.3		$	3.1

	Interest cost	2.5			2.9			7.7			8.9

	Expected return on plan assets	(0.6		)	(0.8		)	(1.9		)	(2.3		)
	Amortization of transition obligation	—			0.7			—			2.1

	Amortization of net loss	5.4			5.2			16.1			15.4

	Amortization of unrecognized prior service cost (A)	(4.1		)	(4.1		)	(12.4		)	(12.4		)
	Total net periodic benefit cost	4.3			4.9			12.8			14.8

	Less: Amount paid by unconsolidated affiliates	0.6			—			1			—

	Net periodic benefit cost (net of unconsolidated affiliates)	$	3.7		$	4.9		$	11.8		$	14.8


	(A)	Unamortized prior service cost is amortized on a straight-line basis over the average remaining service period to the first eligibility age of participants who are expected to receive a benefit and are active at the date of the plan amendment.

	(B)	In addition to the $3.7 million and $4.9 million of net periodic benefit cost recognized during the three months ended September 30, 2013 and 2012, respectively, OG&E recognized an increase in postretirement medical expense during the three months ended September 30, 2013 and 2012 of $0.1 million and $0.1 million, respectively, to maintain the allowable amount to be recovered for postretirement medical expense in the Oklahoma jurisdiction which are included in the Pension tracker regulatory liability (see Note 1).

(C)	In addition to the $11.8 million and $14.8 million of net periodic benefit cost recognized during the nine months ended September 30, 2013 and 2012, respectively, OG&E recognized an increase in postretirement medical expense during the nine months ended September 30, 2013 and 2012 of $0.4 million and $0.8 million, respectively, to maintain the allowable amount to be recovered for postretirement medical expense in the Oklahoma jurisdiction which are included in the Pension tracker regulatory liability (see Note 1).

The capitalized portion of net periodic pension benefit cost was $1.1 million and $3.7 million during the three and nine months ended September 30, 2013 as compared to $1.6 million and $4.7 million during the same period in 2012. The capitalized portion of net periodic postretirement benefit cost was $0.7 million and $2.3 million during the three and nine months ended September 30, 2013 as compared to $1.0 million and $3.0 million during the same period in 2012.

Pension Plan Funding


The Company previously reported in its 2012 Form 10-K that it may contribute up to $35 million to its Pension Plan during 2013. In May 2013, the Company contributed $35 million to its Pension Plan. No additional contributions are expected in 2013.

Report_of_Business_Segments

Report of Business Segments	9 Months Ended
	Sep. 30, 2013
Segment Reporting [Abstract]	'
Report of Business Segments	'
	Report of Business Segments

	Prior to May 1, 2013, the Company's business was divided into three segments as follows: (i) electric utility, which is engaged in the generation, transmission, distribution and sale of electric energy, (ii) natural gas transportation and storage and (iii) natural gas gathering and processing. On March 14, 2013, OGE Energy entered into a Master Formation Agreement with the ArcLight group and CenterPoint Energy, Inc., pursuant to which OGE Energy, the ArcLight Group and CenterPoint Energy, Inc., agreed to form Enable Midstream Partners to own and operate the midstream businesses of OGE Energy and CenterPoint that will initially be structured as a private limited partnership. As a result, effective May 1, 2013, OGE Energy deconsolidated its interest in Enogex Holdings LLC and began accounting for its interest in Enable Midstream Partners using the equity method of accounting. The Company's business is now divided into two segments for financial reporting purposes as follows: (i) electric utility and (ii) natural gas midstream operations. The former natural gas transportation and storage segment and natural gas gathering and processing segment have been combined into the natural gas midstream operations segment and have been restated for all prior periods presented. Equity in earnings of unconsolidated affiliates in the natural gas midstream operations segment includes OGE Energy's equity interest in Enable Midstream Partners from May 1, 2013 through September 30, 2013. Other than equity in earnings of unconsolidated affiliates, all amounts for the natural gas midstream operations segment are through April 30, 2013. Investment in unconsolidated affiliates in the natural gas midstream operations segment represents OGE Energy's investment in Enable Midstream Partners at September 30, 2013. Other Operations primarily includes the operations of the holding company. Intersegment revenues are recorded at prices comparable to those of unaffiliated customers and are affected by regulatory considerations. In reviewing its segment operating results, the Company focuses on operating income as its measure of segment profit and loss, and, therefore, has presented this information below. The following tables summarize the results of the Company's business segments during the three and nine months ended September 30, 2013 and 2012.


	Three Months Ended	Electric Utility			Natural Gas Midstream Operations			Other Operations			Eliminations			Total
	30-Sep-13
	(In millions)
	Operating revenues	$	723.2		$	—		$	—		$	—		$	723.2

	Cost of goods sold	273			—			—			—			273

	Gross margin on revenues	450.2			—			—			—			450.2

	Other operation and maintenance	105.9			—			(3.7		)	—			102.2

	Depreciation and amortization	62.5			—			2.9			—			65.4

	Taxes other than income	20.8			—			0.9			—			21.7

	Operating income (loss)	$	261		$	—		$	(0.1	)	$	—		$	260.9

	Equity in earnings of unconsolidated affiliates	$	—		$	46		$	—		$	—		$	46


	Investment in unconsolidated affiliates (at historical cost)	$	—		$	1,295.80		$	—		$	—		$	1,295.80

	Total assets	$	7,704.00		$	1,311.30		$	172.2		$	(43.3	)	$	9,144.20



	Three Months Ended	Electric Utility			Natural Gas Midstream Operations			Other Operations			Eliminations			Total
	30-Sep-12
	(In millions)
	Operating revenues	$	721		$	412.4		$	—		$	(20.0	)	$	1,113.40

	Cost of goods sold	271.8			288.6			—			(20.8		)	539.6

	Gross margin on revenues	449.2			123.8			—			0.8			573.8

	Other operation and maintenance	108.6			42.3			(3.8		)	—			147.1

	Depreciation and amortization	63.5			26.5			3			—			93

	Taxes other than income	19.1			9.8			0.8			—			29.7

	Operating income (loss)	$	258		$	45.2		$	—		$	0.8		$	304


	Total assets	$	7,082.30		$	2,562.70		$	276.6		$	(215.6	)	$	9,706.00



	Nine Months Ended	Electric Utility			Natural Gas Midstream Operations			Other Operations			Eliminations			Total
	30-Sep-13
	(In millions)
	Operating revenues	$	1,753.30		$	630.4		$	—		$	(24.9	)	$	2,358.80

	Cost of goods sold	733.6			489			—			(26.0		)	1,196.60

	Gross margin on revenues	1,019.70			141.4			—			1.1			1,162.20

	Other operation and maintenance	318			60.9			(6.7		)	—			372.2

Depreciation and amortization	185.8			36.8			9.1			—			231.7

Taxes other than income	63.9			10.5			3.7			—			78.1

Operating income (loss)	$	452		$	33.2		$	(6.1	)	$	1.1		$	480.2

Equity in earnings of unconsolidated affiliates	$	—		$	64.5		$	—		$	—		$	64.5


Investment in unconsolidated affiliates (at historical cost)	$	—		$	1,295.80		$	—		$	—		$	1,295.80

Total assets	$	7,704.00		$	1,311.30		$	172.2		$	(43.3	)	$	9,144.20



Nine Months Ended	Electric Utility			Natural Gas Midstream Operations			Other Operations			Eliminations			Total
30-Sep-12
(In millions)
Operating revenues	$	1,675.70		$	1,186.00		$	—		$	(52.6	)	$	2,809.10

Cost of goods sold	671.9			816.5			—			(54.2		)	1,434.20

Gross margin on revenues	1,003.80			369.5			—			1.6			1,374.90

Other operation and maintenance	333.9			127.3			(13.5		)	—			447.7

Depreciation and amortization	185.9			74.2			10			—			270.1

Impairment of assets	—			0.3			—			—			0.3

Gain on insurance proceeds	—			(7.5		)	—			—			(7.5		)

Taxes other than income	58.4			22.8			3.5			—			84.7

Operating income (loss)	$	425.6		$	152.4		$	—		$	1.6		$	579.6


Total assets	$	7,082.30		$	2,562.70		$	276.6		$	(215.6	)	$	9,706.00

Commitments_and_Contingencies_

Commitments and Contingencies Commitments and Contingencies (Notes)	9 Months Ended
	Sep. 30, 2013
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 16 and 17 to the Company's Consolidated Financial Statements included in the Company's 2012 Form 10-K appropriately represent, in all material respects, the current status of the Company's material commitments and contingent liabilities.

	OG&E *Minimum Fuel Purchase Commitments*

	OG&E has coal contracts for purchases from January 2012 through December 2016. Also, as previously reported, OG&E had entered into multiple-month term natural gas contracts for 26.1 percent of its 2013 annual forecasted natural gas requirements. In February 2013, through a request for proposal, OG&E entered into various multiple-month term natural gas contracts for 84.0 percent of its remaining forecasted 2013 natural gas requirements. OG&E has entered into multiple-month term natural gas contracts for 25.5 percent of its 2014 annual forecasted natural gas requirements. Additional gas supplies to fulfill OG&E's remaining 2014 natural gas requirements will be acquired through additional requests for proposal in early to mid-2014, along with monthly and daily purchases, all of which are expected to be made at market prices.


	OG&E *Long-Term Service Agreement Commitments*



	OG&E has a long-term parts and service maintenance contract for the upkeep of the McClain Plant. The existing contract will expire on January 1, 2015. In May 2013, a new contract was signed that is expected to run for the earlier of 128,000 factored-fired hours or 3,600 factored-fired starts. Based on historical usage and current expectations for future usage, this contract is expected to run until 2030. The contract requires payments based on both a fixed and variable cost component, depending on how much the McClain Plant is used.




	OG&E has a long-term parts and service maintenance contract for the upkeep of the Redbud Plant. In March 2013, the contract was amended to extend the contract coverage for an additional 24,000 factored-fired hours. Based on historical usage and current expectations for future usage, this contract is expected to run until 2027. The contract requires payments based on both a fixed and variable cost component, depending on how much the Redbud Plant is used.





	Enable Midstream Partners Transportation Contract

	Enable Midstream Partners provides gas transmission delivery services to all of PSO's natural gas-fired electric generation facilities in Oklahoma under a firm intrastate transportation contract. The PSO contract provides for a monthly demand charge plus variable transportation charges including fuel. The stated term of the PSO contract was set to expire January 1, 2014, but the contract remains in effect from year to year thereafter unless either party provides written notice of termination to the other party at least 180 days prior to the commencement of the next succeeding annual period. Because neither party provided notice of termination 180 days prior to January 1, 2014, the PSO contract will remain in effect at least through January 1, 2015.

	OGE Holdings Noncancellable Operating Leases

	As a result of the formation of Enable Midstream Partners on May 1, 2013 and the Company's deconsolidation of Enogex Holdings, the Company has no obligations included in its Consolidated Financial Statements at September 30, 2013 under OGE Holdings' noncancellable lease obligations previously disclosed in the Company's 2012 Form 10-K.

	Enogex Energy Resources, LLC Commitments

	As a result of the formation of Enable Midstream Partners on May 1, 2013 and the Company's deconsolidation of Enogex Holdings, the Company has no obligations included in its Consolidated Financial Statements at September 30, 2013, under Enogex Energy Resources, Inc.'s commitments previously disclosed in the Company's 2012 Form 10-K.

	OG&E *Wind Energy Purchased Power Lawsuit*

	In 2009, OG&E entered into a wind energy purchase power agreement with CPV Keenan for the purchase of all the energy output from its 150 MW wind farm in Woodward County, Oklahoma. In August of 2013, CPV Keenan filed suit against OG&E for the non-payment of curtailment charges, for a non-specified amount in excess of $0.1 million. OG&E believes that it is not liable for curtailment charges in this case. Management believes the range of possible outcomes in this suit is between $0 and approximately $10 million. The Company believes that any possible losses in this case would not be quantitatively material to its financial statements and would not have a material adverse effect on the Company's consolidated financial position, results of operations or cash flows.

	Environmental Laws and Regulations

	Federal Clean Air Act New Source Review Litigation

	As previously reported, in July 2008, OG&E received a request for information from the EPA regarding Federal Clean Air Act compliance at OG&E's Muskogee and Sooner generating plants. In recent years, the EPA has issued similar requests to numerous other electric utilities seeking to determine whether various maintenance, repair and replacement projects should have required permits under the Federal Clean Air Act's new source review process. In January 2012, OG&E received a supplemental request for an update of the previously provided information and for some additional information not previously requested. On May 1, 2012, OG&E responded to the EPA's supplemental request for information. On April 26, 2011, the EPA issued a notice of violation alleging that 13 projects occurred at OG&E's Muskogee and Sooner generating plants between 1993 and 2006 without the required new source review permits. The notice of violation also alleges that OG&E's visible emissions at its Muskogee and Sooner generating plants are not in accordance with applicable new source performance standards.

	In March 2013, the DOJ informed OG&E that it was prepared to initiate enforcement litigation concerning the matters identified in the notice of violation. OG&E subsequently met with EPA and DOJ representatives regarding the notice of violation and proposals for resolving the matter without litigation. On July 8, 2013, the United States, at the request of the EPA, filed a complaint for declaratory relief against OG&E in United States District Court for the Western District of Oklahoma (Case No. CIV-13-690-D) alleging that OG&E did not follow the Federal Clean Air Act procedures for projecting emission increases attributable to eight projects that occurred between 2003 and 2006. This complaint seeks to have OG&E submit a new assessment of whether the projects were likely to result in a significant emissions increase. The Sierra Club has intervened in this proceeding and has asserted claims for declaratory relief that are similar to those requested by the United States. OG&E expects to vigorously defend against these claims, but OG&E cannot predict the outcome of such litigation. On August 12, 2013, the Sierra Club filed a complaint against OG&E in the United States District Court for the Eastern District of Oklahoma (Case No. 13-CV-00356) alleging that OG&E modifications made at Unit 6 of the Muskogee generating plant in 2008 were made without obtaining a prevention of significant deterioration permit and that the plant has exceeded emissions limits for opacity and particulate matter. The Sierra Club seeks permanent injunction preventing OG&E from operating the Muskogee generating plant. At this time, OG&E continues to believe that it has acted in compliance with the Federal Clean Air Act.

	If OG&E does not prevail in these proceedings and if a new assessment of the projects were to conclude that they caused a significant emissions increase, the EPA and the Sierra Club could seek to require OG&E to install additional pollution control equipment, including Dry Scrubbers and selective catalytic reduction systems with capital costs in excess of $1.0 billion and pay fines and significant penalties as a result of the allegations in the notice of violation. Section 113 of the Federal Clean Air Act (along with the Federal Civil Penalties Inflation Adjustment Act of 1996) provides for civil penalties as much as $37,500 per day for each violation. The cost of any required pollution control equipment could also be significant. OG&E cannot predict at this time whether it will be legally required to incur any of these costs.


	Other



	In the normal course of business, the Company is confronted with issues or events that may result in a contingent liability. These generally relate to lawsuits or claims made by third parties, including governmental agencies. When appropriate, management consults with legal counsel and other appropriate experts to assess the claim. If, in management's opinion, the Company has incurred a probable loss as set forth by GAAP, an estimate is made of the loss and the appropriate accounting entries are reflected in the Company's Condensed Consolidated Financial Statements. At the present time, based on currently available information, except as otherwise stated above, in Note 14 below, under "Environmental Laws and Regulations" in Item 2 of Part 1 and in Item 1 of Part II of this Form 10-Q, in Notes 16 and 17 of Notes to Consolidated Financial Statements and Item 3 of Part I of the Company's 2012 Form 10-K, the Company believes that any reasonably possible losses in excess of accrued amounts arising out of pending or threatened lawsuits or claims would not be quantitatively material to its financial statements and would not have a material adverse effect on the Company's consolidated financial position, results of operations or cash flows.

Rate_Matters_and_Regulation

Rate Matters and Regulation	9 Months Ended
Rate Matters and Regulation	Sep. 30, 2013
Regulated Operations [Abstract]	'
Rate Matters and Regulation	'
	Rate Matters and Regulation

	Except as set forth below, the circumstances set forth in Note 17 to the Company's Consolidated Financial Statements included in the Company's 2012 Form 10-K appropriately represent, in all material respects, the current status of the Company's regulatory matters.


	Completed Regulatory Matters



	Crossroads Wind Farm




	As previously reported, OG&E signed memoranda of understanding in February 2010 for approximately 197.8 megawatts of wind turbine generators and certain related balance of plant engineering, procurement and construction services associated with the Crossroads wind farm. Also as part of this project, on June 16, 2011, OG&E entered into an interconnection agreement with the SPP for the Crossroads wind farm which allowed the Crossroads wind farm to interconnect at 227.5 megawatts. On August 31, 2012, OG&E filed an application with the APSC requesting approval to recover the Arkansas portion of the costs of the Crossroads wind farm through a rider until such costs are included in OG&E's base rates as part of its next general rate proceeding. On April 15, 2013, the APSC issued an order authorizing OG&E to recover the Arkansas portion of the cost to construct the Crossroads wind farm, effective retroactively to August 1, 2012. The costs will be recovered through the Energy Cost Recovery Rider.





	Market-Based Rate Authority






	On June 29, 2012, OG&E filed its triennial market power update with the FERC to retain its market-based rate authorization in the SPP's energy imbalance service market but to surrender its market-based rate authorization for any market-based rates sales outside of the SPP's energy imbalance service market. On May 2, 2013, the FERC issued an order accepting OG&E's June 2012 triennial market power update.







	Fuel Adjustment Clause Review for Calendar Year 2011








	On July 31, 2012, the OCC Staff filed an application for a public hearing to review and monitor OG&E's application of the 2011 fuel adjustment clause and for a prudence review of OG&E's electric generation, purchased power and fuel procurement processes and costs in calendar year 2011. On April 9, 2013, the OCC administrative law judge recommended that the OCC find that for the calendar year 2011 OG&E's electric generation, purchased power and fuel procurement processes and costs were prudent. On June 18, 2013, the OCC issued an order approving the administrative law judge’s recommendation.









	Pending Regulatory Matters










FERC Order No. 1000, Final Rule on Transmission Planning and Cost Allocation











On July 21, 2011, the FERC issued Order No. 1000, which revised the FERC's existing regulations governing the process for planning enhancements and expansions of the electric transmission grid in a particular region, along with the corresponding process for allocating the costs of such expansions. Order No. 1000 leaves to individual regions to determine whether a previously-approved project is subject to reevaluation and is therefore governed by the new rule.












Order No. 1000 requires, among other things, public utility transmission providers, such as the SPP, to participate in a process that produces a regional transmission plan satisfying certain standards, and requires that each such regional process consider transmission needs driven by public policy requirements (such as state or Federal policies favoring increased use of renewable energy resources). Order No. 1000 also directs public utility transmission providers to coordinate with neighboring transmission planning regions. In addition, Order No. 1000 establishes specific regional cost allocation principles and directs public utility transmission providers to participate in regional and interregional transmission planning processes that satisfy these principles.













On the issue of determining how entities are to be selected to develop and construct the specific transmission projects, Order No. 1000 directs public utility transmission providers to remove from the FERC-jurisdictional tariffs and agreements provisions that establish any Federal "right of first refusal" for the incumbent transmission owner (such as OG&E) regarding transmission facilities selected in a regional transmission planning process, subject to certain limitations. However, Order No. 1000 is not intended to affect the right of an incumbent transmission owner (such as OG&E) to build, own and recover costs for upgrades to its own transmission facilities, and Order No. 1000 does not alter an incumbent transmission owner's use and control of existing rights of way. Order No. 1000 also clarifies that incumbent transmission owners may rely on regional transmission facilities to meet their reliability needs or service obligations. The SPP currently has a "right of first refusal" for incumbent transmission owners and this provision has played a role in OG&E being selected by the SPP to build various transmission projects in Oklahoma. These changes to the "right of first refusal" apply only to "new transmission facilities," which are described as those subject to evaluation or reevaluation (under the applicable local or regional transmission planning process) subsequent to the effective date of the regulatory compliance filings required by the rule, which were filed on November 13, 2012. On May 29, 2013, the Governor signed House Bill 1932 into law which establishes a right of first refusal for Oklahoma incumbent transmission owners, including OG&E, to build new transmission projects with voltages under 300 kilovolts that interconnect to those incumbent entities' existing facilities. OG&E believes this law is consistent with the language of Order No. 1000.














On July 18, 2013, the FERC issued an order on the SPP's Order No. 1000 compliance filing. This order accepted in part and rejected in part the SPP's plan for complying with Order No. 1000. The FERC rejected the SPP's plan to retain the right of first refusal for projects that would operate between 100 kilovolts and 300 kilovolts. However, the FERC clarified that a right of first refusal was appropriate in certain circumstances. It is not clear how the FERC's order will relate to the recently enacted Oklahoma law addressing a right of first refusal for lower voltages. The SPP was ordered to submit another compliance filing by November 15, 2013.















OGE Energy cannot, at this time, determine the precise impact of Order No. 1000 on OG&E. OG&E has filed a petition for review in the D.C. Circuit relating to the same matter. Nevertheless, at the present time, OGE Energy has no reason to believe that the implementation of Order No. 1000 will impact OG&E's transmission projects currently under development and construction for which OG&E has received a notice to proceed from the SPP.
















Fuel Adjustment Clause Review for Calendar Year 2012

















The OCC routinely reviews the costs recovered from customers through OG&E's fuel adjustment clause. On July 31, 2013, the OCC Staff filed an application to review OG&E's fuel adjustment clause for calendar year 2012, including the prudence of OG&E's electric generation, purchased power and fuel procurement costs. OG&E filed the necessary information and documents needed to satisfy the OCC's minimum filing requirement rules on October 9, 2013. A hearing on this matter is scheduled for April 24, 2014.

Request for Modification to Previous Orders

On August 2, 2013, OG&E filed an application at the OCC seeking to make minor modifications to three previous OCC orders. The purpose of the application was to address the timing of certain requirements contained in those orders. The Company's application proposed to address these issues in OG&E's next general rate case thus avoiding the cost associated with a rate case filing now and benefiting customers by deferring the recovery of certain costs identified in the previous orders. On September 3, 2013, the PUD Staff filed a motion to dismiss OG&E's application. PUD Staff requested that the OCC dismiss OG&E's application and issue an order requiring OG&E to file a rate case for the 2012 test year.

On September 11, 2013, the PUD Staff withdrew their motion to dismiss OG&E's application and on September 12, 2013, filed an application requesting a public hearing, review and possible adjustment of the rates and charges of OG&E based on the 2012 test year. To date, no procedural schedule has been established for either the OG&E application or the PUD Staff application.

OG&E *Energy Efficiency Program Filing*

On October 9, 2013 OG&E filed an application with the APSC requesting approval of interim modifications to approved Energy Efficiency Programs, new tariff revisions and the waiver of certain provisions of the Commission’s Rules for Conservation and Energy Efficiency Programs.

Summary_of_Significant_Account1

Summary of Significant Accounting Policies (Policies)	5 Months Ended	9 Months Ended
Summary of Significant Accounting Policies (Policies)	Sep. 30, 2013	Sep. 30, 2013
Organization, Consolidation and Presentation of Financial Statements [Abstract]	'	'
Consolidation, Policy [Policy Text Block]	'	'
		Organization

		The Company is an energy and energy services provider offering physical delivery and related services for both electricity and natural gas primarily in the south central United States. The Company conducts these activities through two business segments: (i) electric utility and (ii) natural gas midstream operations. For a discussion of the change in the Company’s business segments due to the formation of Enable Midstream Partners, see Note 12. For periods prior to May 1, 2013, the Company consolidated Enogex Holdings in its Condensed Consolidated Financial Statements. All significant intercompany transactions have been eliminated in consolidation.

		Effective May 1, 2013, OGE Energy, the ArcLight group and CenterPoint Energy, Inc., formed Enable Midstream Partners to own and operate the midstream businesses of OGE Energy and CenterPoint. In the formation transaction, OGE Energy and ArcLight contributed Enogex LLC to Enable Midstream Partners and the Company deconsolidated its previously held investment in Enogex Holdings and acquired an equity interest in Enable Midstream Partners. The Company determined that its contribution of Enogex LLC to Enable Midstream Partners met the requirements of being in substance real estate and was recorded at historical cost. The general partner of Enable Midstream Partners is equally controlled by CenterPoint and OGE Energy, who each have 50 percent of the management rights. Based on the 50/50 management ownership, with neither company having control, effective May 1, 2013, OGE Energy began accounting for its interest in Enable Midstream Partners using the equity method of accounting.

		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. OG&E is the largest electric utility in Oklahoma and its franchised service territory includes the Fort Smith, Arkansas area. OG&E sold its retail natural gas business in 1928 and is no longer engaged in the natural gas distribution business.


		As discussed below, the Company completed a 2-for-1 stock split of the Company's common stock effective July 1, 2013. All share and per share amounts within this Form 10-Q have been retroactively adjusted to reflect the effects of the stock split for all periods presented.
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 September 30, 2013 and December 31, 2012, the results of its operations for the three and nine months ended September 30, 2013 and 2012 and the results of its cash flows for the nine months ended September 30, 2013 and 2012, have been included and are of a normal recurring nature except as otherwise disclosed.


		Due to seasonal fluctuations and other factors, the Company's operating results for the three and nine months ended September 30, 2013 are not necessarily indicative of the results that may be expected for the year ending December 31, 2013 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 2012 Form 10-K.
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 actual or anticipated 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 actual or anticipated costs and obligations as regulatory assets or liabilities if it is probable, based on regulatory orders or other available evidence, that the cost or obligation will be included in amounts allowable for recovery or refund in future rates.

		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, which could have significant financial effects.

Use of Estimates, Policy [Policy Text Block]	'	'
		Use of Estimates

		In preparing the Condensed Consolidated Financial Statements, management is required to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and contingent liabilities at the date of the Condensed Consolidated Financial Statements and the reported amounts of revenues and expenses during the reporting period. Changes to these assumptions and estimates could have a material effect on the Company's Condensed Consolidated Financial Statements. However, the Company believes it has taken reasonable, but conservative, positions where assumptions and estimates are used in order to minimize the negative financial impact to the Company that could result if actual results vary from the assumptions and estimates. In management's opinion, the areas of the Company where the most significant judgment is exercised for all Company segments includes the determination of Pension Plan assumptions, impairment estimates of long-lived assets (including intangible assets), income taxes, contingency reserves, asset retirement obligations and the allowance for uncollectible accounts receivable. For the electric utility segment, the most significant judgment is also exercised in the valuation of regulatory assets and liabilities and unbilled revenues. For the natural gas midstream operations segment, the most significant judgment is also exercised in the valuation of operating revenues, natural gas purchases, purchase and sale contracts, assets and depreciable lives of property, plant and equipment, amortization methodologies related to intangible assets and impairment assessments of goodwill and equity method investments.
Equity Method Investments, Policy [Policy Text Block]	'	'
	Based on the 50/50 management ownership, with neither company having control, effective May 1, 2013, OGE Energy began accounting for its interest in Enable Midstream Partners using the equity method of accounting.
	Investment in Unconsolidated Affiliate

	OGE Energy's investment in Enable Midstream Partners 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, OGE Energy is not considered the primary beneficiary of Enable Midstream Partners since it does not have the power to direct the activities of Enable Midstream Partners that are considered most significant to the economic performance of Enable Midstream Partners. As discussed above, OGE Energy accounts for the investment in Enable Midstream Partners 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. OGE Energy's maximum exposure to loss related to Enable Midstream Partners is limited to OGE Energy's equity investment in Enable Midstream Partners as presented on the Company's Condensed Consolidated Balance Sheet at September 30, 2013. 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.

	The Company considers distributions received from its unconsolidated affiliates which do not exceed cumulative equity in earnings subsequent to the date of investment to be a return on investment which are classified as operating activities in the Condensed Consolidated Statements of Cash Flows. The Company considers distributions received from its unconsolidated affiliates in excess of cumulative equity in earnings subsequent to the date of investment to be a return of investment which 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 and examples of each 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. Instruments classified as Level 1 include natural gas futures, swaps and options transactions for contracts traded on the NYMEX and settled through a NYMEX clearing broker.

		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. Instruments classified as Level 2 include over-the-counter NYMEX natural gas swaps, natural gas basis swaps and natural gas purchase and sales transactions in markets such that the pricing is closely related to the NYMEX pricing.

		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 utilizes the market approach in determining the fair value of its derivative positions by using either NYMEX published market prices, independent broker pricing data or broker/dealer valuations. The valuations of derivatives with pricing based on NYMEX published market prices may be considered Level 1 if they are settled through a NYMEX clearing broker account with daily margining. Over-the-counter derivatives with NYMEX based prices are considered Level 2 due to the impact of counterparty credit risk. Valuations based on independent broker pricing or broker/dealer valuations may be classified as Level 2 only to the extent they may be validated by an additional source of independent market data for an identical or closely related active market. In certain less liquid markets or for longer-term contracts, forward prices are not as readily available. In these circumstances, contracts are valued using internally developed methodologies that consider historical relationships among various quoted prices in active markets that result in management's best estimate of fair value. These contracts are classified as Level 3.

		The impact to the fair value of derivatives due to credit risk is calculated using the probability of default based on Standard & Poor's Ratings Services and/or internally generated ratings. The fair value of derivative assets is adjusted for credit risk. The fair value of derivative liabilities is adjusted for credit risk only if the impact is deemed material.

		The Company's long-term debt is valued at the carrying amount. The fair value of the Company's long-term debt is based on quoted market prices and estimates of current rates available for similar issues with similar maturities and is classified as Level 2 in the fair value hierarchy except for the Tinker Debt which fair value was based on calculating the net present value of the monthly payments discounted by the Company's current borrowing rate and is classified as Level 3 in the fair value hierarchy.
Derivatives, Offsetting Fair Value Amounts, Policy [Policy Text Block]	'	'
	'	Fair value amounts recognized for forward, interest rate swap, option and other conditional or exchange contracts executed with the same counterparty under a master netting arrangement may be offset. The reporting entity's choice to offset or not must be applied consistently. A master netting arrangement exists if the reporting entity has multiple contracts, whether for the same type of conditional or exchange contract or for different types of contracts, with a single counterparty that are subject to a contractual agreement that provides for the net settlement of all contracts through a single payment in a single currency in the event of default on or termination of any one contract. Offsetting the fair values recognized for forward, interest rate swap, option and other conditional or exchange contracts outstanding with a single counterparty results in the net fair value of the transactions being reported as an asset or a liability in the Condensed Consolidated Balance Sheets. The Company has presented the fair values of its derivative contracts under master netting agreements using a net fair value presentation.
Derivatives, Policy [Policy Text Block]	'	'

		Fair Value Hedges

		For derivative instruments that are designated and qualify as a fair value hedge, the gain or loss on the derivative as well as the offsetting loss or gain on the hedged item attributable to the hedge risk are recognized currently in earnings. The Company includes the gain or loss on the hedged items in Operating Revenues as the offsetting loss or gain on the related hedging derivative.

		Cash Flow Hedges

		For derivatives that are designated and qualify as a cash flow hedge, the effective portion of the change in fair value of the derivative instrument is reported as a component of Accumulated Other Comprehensive Income (Loss) and recognized into earnings in the same period during which the hedged transaction affects earnings. The ineffective portion of a derivative's change in fair value or hedge components excluded from the assessment of effectiveness is recognized currently in earnings. The Company measures the ineffectiveness of commodity cash flow hedges using the change in fair value method whereby the change in the expected future cash flows designated as the hedge transaction are compared to the change in fair value of the hedging instrument. Forecasted transactions, which are designated as the hedged transaction in a cash flow hedge, are regularly evaluated to assess whether they continue to be probable of occurring. If the forecasted transactions are no longer probable of occurring, hedge accounting will cease on a prospective basis and all future changes in the fair value of the derivative will be recognized directly in earnings.

		The Company previously designated as cash flow hedges derivatives for OGE Holdings' NGLs volumes and corresponding keep-whole natural gas resulting from its natural gas processing contracts (processing hedges) and natural gas positions resulting from its natural gas gathering and processing operations and natural gas transportation and storage operations (operational gas hedges). The Company also previously designated as cash flow hedges certain derivatives for certain natural gas storage inventory positions. Due to the deconsolidation effective May 1, 2013, the Company had no material instruments designated as cash flow hedges at September 30, 2013.

		Derivatives Not Designated as Hedging Instruments

		Derivative instruments not designated as hedging instruments are utilized in OGE Holdings' asset management activities. For derivative instruments not designated as hedging instruments, the gain or loss on the derivative is recognized currently in earnings.
Income Tax, Policy [Policy Text Block]	'	'
		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 are being amortized to income over the life of the related property.
		The Company files consolidated income tax returns in the U.S. Federal jurisdiction and various state jurisdictions.
Earnings Per Share, Policy [Policy Text Block]	'	'
		Earnings Per Share

		Basic earnings per share is calculated by dividing net income attributable to OGE Energy by the weighted average number of the Company's common shares outstanding during the period. In the calculation of diluted earnings 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.

Summary_of_Significant_Account2

Summary of Significant Accounting Policies (Tables)	9 Months Ended
Summary of Significant Accounting Policies (Tables)	Sep. 30, 2013
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 at:


	(In millions)	September 30, 2013			December 31, 2012
	Regulatory Assets
	Current
	Oklahoma demand program rider under recovery (A)	$	9.5		$	9.2
	Oklahoma demand program rider under recovery (A)	$	9.5		$	9.2
	Crossroads wind farm rider under recovery (A)	7.2			14.9
	Crossroads wind farm rider under recovery (A)	7.2			14.9
	Other (A)	6.8			2.9
	Other (A)	6.8			2.9
	Total Current Regulatory Assets	$	23.5		$	27
	Total Current Regulatory Assets	$	23.5		$	27
	Non-Current
	Non-Current
	Benefit obligations regulatory asset	$	350.1		$	370.6
	Benefit obligations regulatory asset	$	350.1		$	370.6
	Income taxes recoverable from customers, net	55.7			54.7
	Income taxes recoverable from customers, net	55.7			54.7
	Smart Grid	43.4			42.8
	Smart Grid	43.4			42.8
	Deferred storm expenses	18.3			12.7
	Deferred storm expenses	18.3			12.7
	Unamortized loss on reacquired debt	12.1			13
	Unamortized loss on reacquired debt	12.1			13
	Deferred pension expenses	1.9			4.5
	Deferred pension expenses	1.9			4.5
	Other	14.7			12.3
	Other	14.7			12.3
	Total Non-Current Regulatory Assets	$	496.2		$	510.6
	Total Non-Current Regulatory Assets	$	496.2		$	510.6
	Regulatory Liabilities
	Regulatory Liabilities
	Current
	Current
	Fuel clause over recoveries	$	12		$	109.2
	Fuel clause over recoveries	$	12		$	109.2
	Smart Grid rider over recovery (B)	19.1			24.1
	Smart Grid rider over recovery (B)	19.1			24.1
	Other (B)	2.6			7.8
	Other (B)	2.6			7.8
	Total Current Regulatory Liabilities	$	33.7		$	141.1
	Total Current Regulatory Liabilities	$	33.7		$	141.1
	Non-Current
	Non-Current
	Accrued removal obligations, net	$	219.2		$	218.2
	Accrued removal obligations, net	$	219.2		$	218.2
	Pension tracker	14.2			9.2
	Pension tracker	14.2			9.2
	Deferred pension credits	9.3			17.7
	Deferred pension credits	9.3			17.7
	Total Non-Current Regulatory Liabilities	$	242.7		$	245.1
	Total Non-Current Regulatory Liabilities	$	242.7		$	245.1

	(A)	Included in Other Current Assets on the Condensed Consolidated Balance Sheets.

	(B)	Included in Other Current Liabilities on the Condensed Consolidated Balance Sheets.
Schedule of Change in Asset Retirement Obligation [Table Text Block]	'
	The following table summarizes changes to the Company's asset retirement obligations during the nine months ended September 30, 2013 and 2012.


		Nine Months Ended
		September 30,
	(In millions)	2013			2012
	Balance at January 1	$	54		$	24.8
	Balance at January 1	$	54		$	24.8
	Liabilities settled (A)	(0.4		)	0.3
	Liabilities settled (A)	(0.4		)	0.3
	Accretion expense	1.7			1.6
	Accretion expense	1.7			1.6
	Revisions in estimated cash flows (B)	(0.7		)	26.7
	Revisions in estimated cash flows (B)	(0.7		)	26.7
	Balance at September 30	$	54.6		$	53.4
	Balance at September 30	$	54.6		$	53.4

	(A)	As a result of the formation of Enable Midstream Partners on May 1, 2013, the Company has no obligations at September 30, 2013 under OGE Holdings' asset retirement obligations previously disclosed in the Company's 2012 10-K.

	(B)	Due to changes to OG&E's asset retirement obligations related to its wind farms as a result of changes in the assumption related to the timing of removal used in the valuation of the asset retirement obligations.
Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]	'
	The following table summarizes changes in the components of accumulated other comprehensive loss attributable to OGE Energy during the nine months ended September 30, 2013. All amounts below are presented net of tax and noncontrolling interest.


		Pension Plan and Restoration of Retirement Income Plan							Postretirement Benefit Plans
		Net loss			Prior service cost				Net loss			Prior service cost			Deferred commodity contracts hedging gains			Deferred interest rate swap hedging losses			Less: Noncontrolling interest			Total
	Balance at December 31, 2012	$	(49.3	)	$	0.1			$	(15.7	)	$	7.2		$	0.1		$	(0.5	)	$	(9.0	)	$	(49.1	)
	Balance at December 31, 2012	$	(49.3	)	$	0.1			$	(15.7	)	$	7.2		$	0.1		$	(0.5	)	$	(9.0	)	$	(49.1	)
	Amounts reclassified from accumulated other comprehensive income (loss)	2.8			—				1.6			(1.4		)	0.2			0.2			0.1			3.3
		2.8			—				1.6			(1.4		)	0.2			0.2			0.1			3.3
	Deconsolidation of Enogex Holdings	2.8			—				1			(0.3		)	(0.7		)	—			8.9			(6.1		)
	Deconsolidation of Enogex Holdings	2.8			—				1			(0.3		)	(0.7		)	—			8.9			(6.1		)
	Net current period other comprehensive income (loss)	5.6			—				2.6			(1.7		)	(0.5		)	0.2			9			(2.8		)
	Net current period other comprehensive income (loss)	5.6			—				2.6			(1.7		)	(0.5		)	0.2			9			(2.8		)
	Balance at September 30, 2013	$	(43.7	)	$	0.1			$	(13.1	)	$	5.5		$	(0.4	)	$	(0.3	)	$	—		$	(51.9	)
	Balance at September 30, 2013	$	(43.7	)	$	0.1			$	(13.1	)	$	5.5		$	(0.4	)	$	(0.3	)	$	—		$	(51.9	)
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 loss by the respective line items in net income during the three and nine months ended September 30, 2013.


	Details about Accumulated Other Comprehensive Loss Components	Amount Reclassified from Accumulated Other Comprehensive Income (Loss)						Affected Line Item in the Statement Where Net Income is Presented
		Three Months Ended			Nine Months Ended
		September 30, 2013			September 30, 2013
	Gains (losses) on cash flow hedges
	Commodity contracts	$	(0.6	)	$	(0.4	)	Cost of goods sold
	Interest rate swap	(0.1		)	(0.3		)	Interest expense
		(0.7		)	(0.7		)	Total before tax
		(0.3		)	(0.3		)	Tax benefit
		$	(0.4	)	$	(0.4	)	Net of tax

	Amortization of defined benefit pension items
	Actuarial gains (losses)	$	(1.5	)	$	(4.6	)	(A)
	Prior service cost	—			—			(A)
	Prior service cost	—			—			(A)
		(1.5		)	(4.6		)	Total before tax
		(0.6		)	(1.8		)	Tax benefit
		(0.9		)	(2.8		)	Net of tax
		—			(0.1		)	Noncontrolling interest
		—			(0.1		)	Noncontrolling interest
		$	(0.9	)	$	(2.7	)	Net of tax and noncontrolling interest

	Amortization of postretirement benefit plan items
	Actuarial gains (losses)	$	(0.9	)	$	(2.5	)	(A)
	Prior service cost	0.8			2.2			(A)
	Prior service cost	0.8			2.2			(A)
		(0.1		)	(0.3		)	Total before tax
		—			(0.1		)	Tax benefit
		—			(0.1		)	Tax benefit
		$	(0.1	)	$	(0.2	)	Net of tax

	Total reclassifications for the period	$	(1.4	)	$	(3.3	)	Net of tax and noncontrolling interest

	(A)	These accumulated other comprehensive income (loss) components are included in the computation of net periodic benefit cost (see Note 11 for additional information).

Investment_in_Unconsolidated_A1

Investment in Unconsolidated Affiliates (Tables)	2 Months Ended
	Jun. 30, 2013
Related Party Transactions [Abstract]	'
Schedule of Related Party Transactions [Table Text Block]	'
	Related Party Transactions with Enable Midstream Partners


		Three Months Ended		Five Months Ended
		September 30,		September 30,
	(In millions)	2013		2013
	Operating Revenues:
	Electricity to power electric compression assets	$	3.9	$	5.2

	Cost of Goods Sold:
	Natural gas transportation services	$	8.7	$	14.5

	Natural gas storage services	3.1		5.4

	Natural gas purchases (A)	9.4		11.9


	(A)	At September 30, 2013, there was $1.4 million of natural gas purchases recorded for these activities.

Investment_in_Unconsolidated_A2

Investment in Unconsolidated Affiliates Summarized Balance Sheet Information of Equity Method Investment (Tables)	Sep. 30, 2013
Summarized Financial Information of Equity Method Investment [Line Items]	'
Summarized Balance Sheet Financial Information, Equity Method Investment [Table Text Block]	'
	As Enable Midstream Partners began operations on May 1, 2013, summarized unaudited financial information for 100 percent of Enable Midstream Partners is presented below at September 30, 2013 and for the three and five months ended September 30, 2013.


	Balance Sheet	September 30, 2013
		(In millions)
	Current assets	$	427.5

	Non-current assets	10,537.10

	Current liabilities	622.1

	Non-current liabilities	2,140.40

Investment_in_Unconsolidated_A3

Investment in Unconsolidated Affiliates Summarized Income Statement of Equity Method Investment (Tables)	2 Months Ended
	Jun. 30, 2013
Summarized Financial Information of Equity Method Investment [Line Items]	'
Summarized Income Statement Financial Information, Equity Method Investment [Table Text Block]	'


		Three Months Ended		Five Months Ended
	Income Statement	30-Sep-13		30-Sep-13
		(In millions)
	Operating revenues	$	796.4	$	1,298.40

	Gross margin	337.1		544.5

	Operating income	132		206.7

	Net income	123.3		188.4

Investment_in_Unconsolidated_A4

Investment in Unconsolidated Affiliates Reconciliation of Equity in Earnings of Unconsolidated Affiliates (Tables)	5 Months Ended
	Sep. 30, 2013
Reconciliation of Equity in Earnings of Unconsolidated Affiliates [Line Items]	'
Reconciliation of Equity in Earnings of Unconsolidated Affiliates [Table Text Block]	'


		Three Months Ended		Five Months Ended
	Reconciliation of Equity in Earnings of Unconsolidated Affiliates	30-Sep-13		30-Sep-13
		(In millions)
	OGE's 28.5% share of Enable Net Income	$	35.1	$	53.6

	Amortization of basis difference	5.9		5.9

	Elimination of Enogex Holdings fair value adjustments	5		5

	OGE's Equity in earnings of unconsolidated affiliates	$	46	$	64.5

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2013
Fair Value Disclosures [Abstract]	'
Schedule of Assets and Liabilities Measured at Fair Value on a Recurring Basis [Table Text Block]	'
	The Company had no material financial instruments measured at fair value on a recurring basis at September 30, 2013. The following table summarizes the Company's assets and liabilities that are measured at fair value on a recurring basis at December 31, 2012 as well as presents the Company's commodity contracts fair value included in the Company's Condensed Consolidated Balance Sheet at December 31, 2012. The Company adopted the FASB's accounting guidance requiring additional disclosures for balance sheet offsetting of assets and liabilities effective January 1, 2013. The Company posted $0.2 million of collateral at December 31, 2012 which has been included within netting adjustments in the table below. The Company held no collateral at December 31, 2012. The Company has offset all amounts subject to master netting agreements in the Company's Condensed Consolidated Balance Sheet at December 31, 2012. The Company held no Level 3 investments at December 31, 2012.


	December 31, 2012
	(In millions)	Commodity Contracts						Gas Imbalances (A)
		Assets			Liabilities			Assets (B)		Liabilities (C)
	Quoted market prices in active market for identical assets (Level 1)	$	5		$	5		$	—	$	—

	Significant other observable inputs (Level 2)	0.5			0.5			3.1		3.8

	Total fair value	5.5			5.5			3.1		3.8

	Netting adjustments	(5.0		)	(5.2		)	—		—

	Total	$	0.5		$	0.3		$	3.1	$	3.8


	(A)	The Company uses the market approach to fair value its gas imbalance assets and liabilities, using an average of the Inside FERC Gas Market Report for Panhandle Eastern Pipe Line Co. (Texas, Oklahoma Mainline), ONEOK (Oklahoma) and ANR Pipeline (Oklahoma) indices.

	(B)	Gas imbalance assets exclude fuel reserves for under retained fuel due from shippers of $5.9 million at December 31, 2012, which fuel reserves are based on the value of natural gas at the time the imbalance was created and which are not subject to revaluation at fair market value.

	(C)	Gas imbalance liabilities exclude fuel reserves for over retained fuel due to shippers of $1.2 million at December 31, 2012, which fuel reserves are based on the value of natural gas at the time the imbalance was created and which are not subject to revaluation at fair market value.
Schedule of Fair Value and Carrying Amount of PRM Financial Instruments [Table Text Block]	'
	The following table summarizes the fair value and carrying amount of the Company's financial instruments at September 30, 2013 and December 31, 2012.


		September 30, 2013						December 31, 2012
	(In millions)	Carrying Amount			Fair			Carrying Amount		Fair
					Value					Value
	Long-Term Debt
	OG&E Senior Notes	$	2,154.30		$	2,455.20		$	1,904.20	$	2,401.60

	OG&E Industrial Authority Bonds	135.4			135.4			135.4		135.4

	OG&E Tinker Debt	10.4			9.1			10.7		10

	OGE Energy Senior Notes	99.9			103.7			99.9		106.3

	Enogex LLC Senior Notes	(A)			(A)			448.4		493.4

	Enogex LLC Term Loan	(A)			(A)			250		250


	(A)	As a result of the formation of Enable Midstream Partners on May 1, 2013 and the Company's deconsolidation of Enogex Holdings, the Company's consolidated financial statements do not include any obligations for the Enogex LLC Senior Notes and Enogex LLC Term Loan as of May 1, 2013.

Derivative_Instruments_and_Hed1

Derivative Instruments and Hedging Activities (Tables)	9 Months Ended
	Sep. 30, 2013
Derivative Instruments and Hedging Activities Disclosure [Abstract]	'
Schedule of Derivative Instruments in Statement of Financial Position, Fair Value [Table Text Block]	'
	Balance Sheet Presentation Related to Derivative Instruments

	The Company had no material derivative instruments included in its Condensed Consolidated Balance Sheet at September 30, 2013. The fair value of the derivative instruments that are presented in the Company's Condensed Consolidated Balance Sheet at December 31, 2012 are as follows:


			Fair Value
	Instrument	Balance Sheet Location	Assets			Liabilities
			(In millions)
	Derivatives Designated as Hedging Instruments
	Natural Gas
	Financial Futures/Swaps	Other Current Assets	$	—		$	0.5

	Total		$	—		$	0.5


	Derivatives Not Designated as Hedging Instruments
	Natural Gas
	Financial Futures/Swaps	Current PRM	$	0.1		$	—

		Other Current Assets	5			4.7

	Physical Purchases/Sales	Current PRM	0.4			0.3

	Total		$	5.5		$	5

	Total Gross Derivatives (A)		$	5.5		$	5.5


	(A)	See Note 4 for a reconciliation of the Company's total derivatives fair value to the Company's Condensed Consolidated Balance Sheet at December 31, 2012.
Schedule of Derivative Instruments, Gain (Loss) in Statement of Financial Performance [Table Text Block]	'
	Income Statement Presentation Related to Derivative Instruments

	The following tables present the effect of derivative instruments on the Company's Condensed Consolidated Statement of Income for the three months ended September 30, 2012.

	Derivatives in Cash Flow Hedging Relationships


	(In millions)	Amount Recognized in Other Comprehensive Income			Amount Reclassified from Accumulated Other Comprehensive Income (Loss) into Income

								Amount Recognized in Income
	Natural Gas Financial Futures/Swaps	$	(0.8	)	$	—		$	—

	Interest Rate Swap	—			(0.1		)	—

	Total	$	(0.8	)	$	(0.1	)	$	—


	Derivatives Not Designated as Hedging Instruments



	(In millions)	Amount Recognized in Income
	Natural Gas Physical Purchases/Sales	$	(2.7	)
	Natural Gas Financial Futures/Swaps	(0.2		)
	Total	$	(2.9	)

	The following tables present the effect of derivative instruments on the Company's Condensed Consolidated Statement of Income for the nine months ended September 30, 2012.

	Derivatives in Cash Flow Hedging Relationships


	(In millions)	Amount Recognized in Other Comprehensive Income			Amount Reclassified from Accumulated Other Comprehensive Income (Loss) into Income

								Amount Recognized in Income
	Natural Gas Financial Futures/Swaps	$	(1.0	)	$	5.2		$	—

	Interest Rate Swap	—			(0.3		)	—

	Total	$	(1.0	)	$	4.9		$	—


	Derivatives Not Designated as Hedging Instruments


	(In millions)	Amount Recognized in Income
	Natural Gas Physical Purchases/Sales	$	(8.8	)
	Natural Gas Financial Futures/Swaps	0.8

	Total	$	(8.0	)

StockBased_Compensation_Tables

Stock-Based Compensation (Tables)	9 Months Ended
	Sep. 30, 2013
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]	'
Schedule of Compensation Cost for Share-based Payment Arrangements, Allocation of Share-based Compensation Costs 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 nine months ended September 30, 2013 and 2012 related to the Company's performance units and restricted stock.


		Three Months Ended				Nine Months Ended
		September 30,				September 30,
	(In millions)	2013		2012		2013		2012
	Performance units
	Total shareholder return	$	2.5	$	1.9	$	6.4	$	5.7

	Earnings per share	0.6		0.7		1.9		2

	Total performance units	3.1		2.6		8.3		7.7

	Restricted stock	0.1		0.1		0.3		0.5

	Total compensation expense	3.2		2.7		8.6		8.2

	Less: Amount paid by unconsolidated affiliates	1.4		—		2		—

	Net compensation expense	$	1.8	$	2.7	$	6.6	$	8.2

	Income tax benefit	$	0.7	$	1	$	2.6	$	3.2

Common_Equity_Tables

Common Equity (Tables)	9 Months Ended
	Sep. 30, 2013
Equity [Abstract]	'
Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]	'
	Basic and diluted earnings per share for the Company were calculated as follows:


		Three Months Ended				Nine Months Ended
		September 30,				September 30,
	(In millions)	2013		2012		2013		2012
	Net Income Attributable to OGE Energy	$	215.2	$	185.5	$	330	$	316.5

	Average Common Shares Outstanding
	Basic average common shares outstanding	198.4		197.4		198.1		197

	Effect of dilutive securities:
	Contingently issuable shares (performance units)	1.3		0.9		1.2		0.9

	Diluted average common shares outstanding	199.7		198.3		199.3		197.9

	Basic Earnings Per Average Common Share Attributable to OGE Energy Common Shareholders	$	1.08	$	0.94	$	1.67	$	1.61

	Diluted Earnings Per Average Common Share Attributable to OGE Energy Common Shareholders	$	1.08	$	0.94	$	1.66	$	1.6

	Anti-dilutive shares excluded from earnings per share calculation	—		—		—		—

LongTerm_Debt_Tables

Long-Term Debt (Tables)	9 Months Ended
	Sep. 30, 2013
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 as follows:


	SERIES			DATE DUE	AMOUNT
					(In millions)
	0.18%	-	0.34%	Garfield Industrial Authority, January 1, 2025	$	47

	0.12%	-	0.39%	Muskogee Industrial Authority, January 1, 2025	32.4

	0.11%	-	0.30%	Muskogee Industrial Authority, June 1, 2027	56

	Total (redeemable during next 12 months)				$	135.4

ShortTerm_Debt_and_Credit_Faci1

Short-Term Debt and Credit Facilities (Tables)

9 Months Ended

Sep. 30, 2013

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 September 30, 2013.

Aggregate

Amount

Weighted-Average

Entity

Commitment

Outstanding (A)

Interest Rate

Maturity

(In millions)

OGE Energy (B)

750

447

0.3

(E)

13-Dec-17

(F)

OG&E (C)

400

2.1

0.53

(E)

13-Dec-17

(F)

Total

1,150.00

(D)

449.1

0.3

(A)

Includes direct borrowings under the revolving credit agreements, commercial paper borrowings and letters of credit at September 30, 2013.

(B)

This bank facility is available to back up OGE Energy's commercial paper borrowings and to provide revolving credit borrowings. This bank facility can also be used as a letter of credit facility.

(C)

This bank facility is available to back up OG&E's commercial paper borrowings and to provide revolving credit borrowings. This bank facility can also be used as a letter of credit facility.

(D)

(E)

Represents the weighted-average interest rate for the outstanding borrowings under the revolving credit agreements, commercial paper borrowings and letters of credit.

(F)

Retirement_Plans_and_Postretir1

Retirement Plans and Postretirement Benefit Plans (Tables)	9 Months Ended
	Sep. 30, 2013
Defined Benefit Pension Plans and Defined Benefit Postretirement Plans Disclosure [Abstract]	'
Schedule of Defined Benefit Plans Disclosures [Table Text Block]	'
	The details of net periodic benefit cost of the Company's Pension Plan, the Restoration of Retirement Income Plan and the postretirement benefit plans included in the Condensed Consolidated Financial Statements are as follows:

	Net Periodic Benefit Cost


		Pension Plan												Restoration of Retirement
														Income Plan
		Three Months						Nine Months						Three Months				Nine Months
		Ended						Ended						Ended				Ended
		September 30,						September 30,						September 30,				September 30,
	(In millions)	2013 (B)			2012 (B)			2013 (C)			2012 (C)			2013 (B)		2012 (B)		2013 (C)		2012 (C)
	Service cost	$	4.8		$	4.5		$	14.3		$	13.5		$	0.3	$	0.3	$	0.9	$	0.8

	Interest cost	6.6			7.5			20			22.5			0.1		0.1		0.4		0.4

	Expected return on plan assets	(12.1		)	(11.5		)	(36.3		)	(34.5		)	—		—		—		—

	Amortization of net loss	6.6			6			19.8			17.9			0.1		0.1		0.3		0.3

	Amortization of unrecognized prior service cost (A)	0.5			0.5			1.4			1.6			0.1		0.2		0.2		0.5

	Total net periodic benefit cost	6.4			7			19.2			21			0.6		0.7		1.8		2

	Less: Amount paid by unconsolidated affiliates	1.5			—			2.5			—			0.1		—		0.1		—

	Net periodic benefit cost (net of unconsolidated affiliates)	$	4.9		$	7		$	16.7		$	21		$	0.5	$	0.7	$	1.7	$	2


	(A)	Unamortized prior service cost is amortized on a straight-line basis over the average remaining service period to the first eligibility age of participants who are expected to receive a benefit and are active at the date of the plan amendment.

	(B)	In addition to the $5.4 million and $7.7 million of net periodic benefit cost recognized during the three months ended September 30, 2013 and 2012, respectively, OG&E recognized an increase in pension expense during the three months ended September 30, 2013 and 2012 of $1.5 million and $1.9 million, respectively, to maintain the allowable amount to be recovered for pension expense in the Oklahoma jurisdiction which are included in the Pension tracker regulatory liability (see Note 1).

	(C)	In addition to the $18.4 million and $23.0 million of net periodic benefit cost recognized during the nine months ended September 30, 2013 and 2012, respectively, OG&E recognized an increase in pension expense during the nine months ended September 30, 2013 and 2012 of $4.6 million and $7.6 million, respectively, to maintain the allowable amount to be recovered for pension expense in the Oklahoma jurisdiction which are included in the Pension tracker regulatory liability (see Note 1).


		Postretirement Benefit Plans
		Three Months						Nine Months
		Ended						Ended
		September 30,						September 30,
	(In millions)	2013 (B)			2012 (B)			2013 (C)			2012 (C)
	Service cost	$	1.1		$	1		$	3.3		$	3.1

	Interest cost	2.5			2.9			7.7			8.9

	Expected return on plan assets	(0.6		)	(0.8		)	(1.9		)	(2.3		)
	Amortization of transition obligation	—			0.7			—			2.1

	Amortization of net loss	5.4			5.2			16.1			15.4

	Amortization of unrecognized prior service cost (A)	(4.1		)	(4.1		)	(12.4		)	(12.4		)
	Total net periodic benefit cost	4.3			4.9			12.8			14.8

	Less: Amount paid by unconsolidated affiliates	0.6			—			1			—

	Net periodic benefit cost (net of unconsolidated affiliates)	$	3.7		$	4.9		$	11.8		$	14.8


	(A)	Unamortized prior service cost is amortized on a straight-line basis over the average remaining service period to the first eligibility age of participants who are expected to receive a benefit and are active at the date of the plan amendment.

	(B)	In addition to the $3.7 million and $4.9 million of net periodic benefit cost recognized during the three months ended September 30, 2013 and 2012, respectively, OG&E recognized an increase in postretirement medical expense during the three months ended September 30, 2013 and 2012 of $0.1 million and $0.1 million, respectively, to maintain the allowable amount to be recovered for postretirement medical expense in the Oklahoma jurisdiction which are included in the Pension tracker regulatory liability (see Note 1).

	(C)	In addition to the $11.8 million and $14.8 million of net periodic benefit cost recognized during the nine months ended September 30, 2013 and 2012, respectively, OG&E recognized an increase in postretirement medical expense during the nine months ended September 30, 2013 and 2012 of $0.4 million and $0.8 million, respectively, to maintain the allowable amount to be recovered for postretirement medical expense in the Oklahoma jurisdiction which are included in the Pension tracker regulatory liability (see Note 1).

Report_of_Business_Segments_Ta

Report of Business Segments (Tables)	9 Months Ended
	Sep. 30, 2013
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 nine months ended September 30, 2013 and 2012.


	Three Months Ended	Electric Utility			Natural Gas Midstream Operations			Other Operations			Eliminations			Total
	30-Sep-13
	(In millions)
	Operating revenues	$	723.2		$	—		$	—		$	—		$	723.2

	Cost of goods sold	273			—			—			—			273

	Gross margin on revenues	450.2			—			—			—			450.2

	Other operation and maintenance	105.9			—			(3.7		)	—			102.2

	Depreciation and amortization	62.5			—			2.9			—			65.4

	Taxes other than income	20.8			—			0.9			—			21.7

	Operating income (loss)	$	261		$	—		$	(0.1	)	$	—		$	260.9

	Equity in earnings of unconsolidated affiliates	$	—		$	46		$	—		$	—		$	46


	Investment in unconsolidated affiliates (at historical cost)	$	—		$	1,295.80		$	—		$	—		$	1,295.80

	Total assets	$	7,704.00		$	1,311.30		$	172.2		$	(43.3	)	$	9,144.20



	Three Months Ended	Electric Utility			Natural Gas Midstream Operations			Other Operations			Eliminations			Total
	30-Sep-12
	(In millions)
	Operating revenues	$	721		$	412.4		$	—		$	(20.0	)	$	1,113.40

	Cost of goods sold	271.8			288.6			—			(20.8		)	539.6

	Gross margin on revenues	449.2			123.8			—			0.8			573.8

	Other operation and maintenance	108.6			42.3			(3.8		)	—			147.1

	Depreciation and amortization	63.5			26.5			3			—			93

	Taxes other than income	19.1			9.8			0.8			—			29.7

	Operating income (loss)	$	258		$	45.2		$	—		$	0.8		$	304


	Total assets	$	7,082.30		$	2,562.70		$	276.6		$	(215.6	)	$	9,706.00



	Nine Months Ended	Electric Utility			Natural Gas Midstream Operations			Other Operations			Eliminations			Total
	30-Sep-13
	(In millions)
	Operating revenues	$	1,753.30		$	630.4		$	—		$	(24.9	)	$	2,358.80

	Cost of goods sold	733.6			489			—			(26.0		)	1,196.60

	Gross margin on revenues	1,019.70			141.4			—			1.1			1,162.20

	Other operation and maintenance	318			60.9			(6.7		)	—			372.2

	Depreciation and amortization	185.8			36.8			9.1			—			231.7

Taxes other than income	63.9			10.5			3.7			—			78.1

Operating income (loss)	$	452		$	33.2		$	(6.1	)	$	1.1		$	480.2

Equity in earnings of unconsolidated affiliates	$	—		$	64.5		$	—		$	—		$	64.5


Investment in unconsolidated affiliates (at historical cost)	$	—		$	1,295.80		$	—		$	—		$	1,295.80

Total assets	$	7,704.00		$	1,311.30		$	172.2		$	(43.3	)	$	9,144.20



Nine Months Ended	Electric Utility			Natural Gas Midstream Operations			Other Operations			Eliminations			Total
30-Sep-12
(In millions)
Operating revenues	$	1,675.70		$	1,186.00		$	—		$	(52.6	)	$	2,809.10

Cost of goods sold	671.9			816.5			—			(54.2		)	1,434.20

Gross margin on revenues	1,003.80			369.5			—			1.6			1,374.90

Other operation and maintenance	333.9			127.3			(13.5		)	—			447.7

Depreciation and amortization	185.9			74.2			10			—			270.1

Impairment of assets	—			0.3			—			—			0.3

Gain on insurance proceeds	—			(7.5		)	—			—			(7.5		)

Taxes other than income	58.4			22.8			3.5			—			84.7

Operating income (loss)	$	425.6		$	152.4		$	—		$	1.6		$	579.6


Total assets	$	7,082.30		$	2,562.70		$	276.6		$	(215.6	)	$	9,706.00

Summary_of_Significant_Account3

Summary of Significant Accounting Policies, Regulated Operations (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012
In Millions, unless otherwise specified	Sep. 30, 2013		Dec. 31, 2012
Schedule of Regulatory Assets and Liabilities [Line Items]	'		'
Total Current Regulatory Assets	$23.50		$27
Total Non-Current Regulatory Assets	496.2		510.6
Fuel clause over recoveries	12		109.2
Total Current Regulatory Liabilities	33.7		141.1
Total Non-Current Regulatory Liabilities	242.7		245.1
Smart Grid rider over recovery [Member]	'		'
Schedule of Regulatory Assets and Liabilities [Line Items]	'		'
Total Current Regulatory Liabilities	19.1	[1]	24.1	[1]
Other [Member]	'		'
Schedule of Regulatory Assets and Liabilities [Line Items]	'		'
Total Current Regulatory Liabilities	2.6	[1]	7.8	[1]
Accrued removal obligations, net	'		'
Schedule of Regulatory Assets and Liabilities [Line Items]	'		'
Total Non-Current Regulatory Liabilities	219.2		218.2
Pension tracker	'		'
Schedule of Regulatory Assets and Liabilities [Line Items]	'		'
Total Non-Current Regulatory Liabilities	14.2		9.2
Deferred pension credits	'		'
Schedule of Regulatory Assets and Liabilities [Line Items]	'		'
Total Non-Current Regulatory Liabilities	9.3		17.7
Crossroads wind farm rider under recovery [Member]	'		'
Schedule of Regulatory Assets and Liabilities [Line Items]	'		'
Total Current Regulatory Assets	7.2	[2]	14.9	[2]
Oklahoma demand program rider under recovery [Member]	'		'
Schedule of Regulatory Assets and Liabilities [Line Items]	'		'
Total Current Regulatory Assets	9.5	[2]	9.2	[2]
Other [Member]	'		'
Schedule of Regulatory Assets and Liabilities [Line Items]	'		'
Total Current Regulatory Assets	6.8	[2]	2.9	[2]
Total Non-Current Regulatory Assets	14.7		12.3
Benefit obligations regulatory asset	'		'
Schedule of Regulatory Assets and Liabilities [Line Items]	'		'
Total Non-Current Regulatory Assets	350.1		370.6
Income taxes recoverable from customers, net	'		'
Schedule of Regulatory Assets and Liabilities [Line Items]	'		'
Total Non-Current Regulatory Assets	55.7		54.7
Smart Grid	'		'
Schedule of Regulatory Assets and Liabilities [Line Items]	'		'
Total Non-Current Regulatory Assets	43.4		42.8
Deferred storm expenses	'		'
Schedule of Regulatory Assets and Liabilities [Line Items]	'		'
Total Non-Current Regulatory Assets	18.3		12.7
Unamortized loss on reacquired debt	'		'
Schedule of Regulatory Assets and Liabilities [Line Items]	'		'
Total Non-Current Regulatory Assets	12.1		13
Deferred pension expenses	'		'
Schedule of Regulatory Assets and Liabilities [Line Items]	'		'
Total Non-Current Regulatory Assets	$1.90		$4.50

[1]	Included in Other Current Liabilities on the Condensed Consolidated Balance Sheets.
[2]	Included in Other Current Assets on the Condensed Consolidated Balance Sheets.

Summary_of_Significant_Account4

Summary of Significant Accounting Policies Asset Retirement Obligation (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013		Sep. 30, 2012
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]	'		'
Balance at January 1	$54		$24.80
Liabilities settled	-0.4	[1]	0.3
Accretion expense	1.7		1.6
Revisions in estimated cash flows	-0.7		26.7	[2]
Balance at September 30	54.6		53.4
OGE Enogex Holdings [Member]	'		'
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]	'		'
Balance at September 30	$0		'

[1]	As a result of the formation of Enable Midstream Partners on May 1, 2013, the Company has no obligations at SeptemberB 30, 2013 under OGE Holdings' asset retirement obligations previously disclosed in the Company's 2012 10-K.
[2]	Due to changes to OG&E's asset retirement obligations related to its wind farms as a result of changes in the assumption related to the timing of removal used in the valuation of the asset retirement obligations.

Summary_of_Significant_Account5

Summary of Significant Accounting Policies Accumulated Other Comprehensive Income (Loss) (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Accumulated Other Comprehensive Income (Loss), Net of Tax	($51.90)	'	($51.90)	'	($49.10)
Amounts reclassified from accumulated other comprehensive income (loss)	-0.9	-0.8	-2.8	-2.3	'
Amounts reclassified from accumulated other comprehensive income (loss)	'	'	3.3	'	'
Deconsolidation of Enogex Holdings	0	0	6.1	0	'
Deconsolidation of Enogex Holdings	'	'	-6.1	'	'
Net current period other comprehensive income (loss)	'	'	-2.8	'	'
Commodity Contract [Member]	'	'	'	'	'
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax	-0.4	'	-0.4	'	0.1
Amounts reclassified from accumulated other comprehensive income (loss)	'	'	0.2	'	'
Deconsolidation of Enogex Holdings	'	'	-0.7	'	'
Net current period other comprehensive income (loss)	'	'	-0.5	'	'
Interest Rate Swap [Member]	'	'	'	'	'
Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax	-0.3	'	-0.3	'	-0.5
Amounts reclassified from accumulated other comprehensive income (loss)	'	'	0.2	'	'
Deconsolidation of Enogex Holdings	'	'	0	'	'
Net current period other comprehensive income (loss)	'	'	0.2	'	'
Noncontrolling Interest [Member]	'	'	'	'	'
Accumulated Other Comprehensive Income (Loss), Net of Tax	0	'	0	'	-9
Amounts reclassified from accumulated other comprehensive income (loss)	'	'	0.1	'	'
Deconsolidation of Enogex Holdings	'	'	8.9	'	'
Net current period other comprehensive income (loss)	'	'	9	'	'
Pension Plans, Defined Benefit [Member] \| Defined Benefit Plan Income Loss [Member]	'	'	'	'	'
Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax	-43.7	'	-43.7	'	-49.3
Amounts reclassified from accumulated other comprehensive income (loss)	'	'	2.8	'	'
Deconsolidation of Enogex Holdings	'	'	2.8	'	'
Net current period other comprehensive income (loss)	'	'	5.6	'	'
Pension Plans, Defined Benefit [Member] \| Defined Benefit Plan Prior Service Cost [Member]	'	'	'	'	'
Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax	0.1	'	0.1	'	0.1
Amounts reclassified from accumulated other comprehensive income (loss)	'	'	0	'	'
Deconsolidation of Enogex Holdings	'	'	0	'	'
Net current period other comprehensive income (loss)	'	'	0	'	'
Other Postretirement Benefit Plans, Defined Benefit [Member] \| Defined Benefit Plan Income Loss [Member]	'	'	'	'	'
Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax	-13.1	'	-13.1	'	-15.7
Amounts reclassified from accumulated other comprehensive income (loss)	'	'	1.6	'	'
Deconsolidation of Enogex Holdings	'	'	1	'	'
Net current period other comprehensive income (loss)	'	'	2.6	'	'
Other Postretirement Benefit Plans, Defined Benefit [Member] \| Defined Benefit Plan Prior Service Cost [Member]	'	'	'	'	'
Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax	5.5	'	5.5	'	7.2
Amounts reclassified from accumulated other comprehensive income (loss)	'	'	-1.4	'	'
Deconsolidation of Enogex Holdings	'	'	-0.3	'	'
Net current period other comprehensive income (loss)	'	'	($1.70)	'	'

Summary_of_Significant_Account6

Summary of Significant Accounting Policies Accumulated Other Comprehensive Income (Loss) Reclassifications out of AOCI (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'	'	'
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax	$0.30	$0	$0.20	($1.60)
Amounts Reclassified from accumulated other comprehensive income (loss)	-0.3	0	-0.2	3.6
Amounts Reclassified from Accumulated OCI, Net of Tax and Noncontrolling Interest	-1.4	'	-3.3	'
Commodity Contract [Member]	'	'	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'	'	'
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax	-0.6	'	-0.4	'
Interest Rate Swap [Member]	'	'	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'	'	'
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax	-0.1	'	-0.3	'
Derivative [Member]	'	'	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'	'	'
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, before Tax	-0.7	'	-0.7	'
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax	-0.3	'	-0.3	'
Amounts Reclassified from accumulated other comprehensive income (loss)	-0.4	'	-0.4	'
Postretirement Benefit Plan [Member]	'	'	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'	'	'
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Gain (Loss), before Tax	-0.9	'	-2.5	'
Other Comprehensive (Income) Loss, Amortization Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Prior Service Cost (Credit), before Tax	0.8	'	2.2	'
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, before Tax	-0.1	'	-0.3	'
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, Tax	0	'	-0.1	'
Amounts reclassified from accumulated other comprehensive income (loss)	-0.1	'	-0.2	'
Pension Plan [Member]	'	'	'	'
Accumulated Other Comprehensive Income (Loss) [Line Items]	'	'	'	'
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Gain (Loss), before Tax	-1.5	'	-4.6	'
Other Comprehensive (Income) Loss, Amortization Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Prior Service Cost (Credit), before Tax	0	'	0	'
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, before Tax	-1.5	'	-4.6	'
Other Comprehensive (Income) Loss, Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, Tax	-0.6	'	-1.8	'
Amounts reclassified from accumulated other comprehensive income (loss)	-0.9	'	-2.8	'
Amortization of Defined Benefit Pension Items, Amount Reclassified from Accumulated OCI, Noncontrolling Interest	0	'	-0.1	'
Amounts Reclassified from Accumulated OCI, Net of Tax and Noncontrolling Interest	($0.90)	'	($2.70)	'

Summary_of_Significant_Account7

Summary of Significant Accounting Policies Forward Stock Split (Details)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Class of Stock [Line Items]	'	'
Common Stock, Shares Authorized	450	225

Investment_in_Unconsolidated_A5

Investment in Unconsolidated Affiliates (Details) (USD $)	5 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013		1-May-13
Value of Midstream Operations Assets or Equity Acquired	'		50
Line of Credit Facility, Maximum Borrowing Capacity	1,150		'
Value of Aggregate Midstream Operations Assets or Equity Acquired by Parties Not Offered in Midstream Partnership	'		100
Enogex LLC [Member]	'		'
Percentage of Enogex LLC Contributed	'		100.00%
Line of Credit Facility, Maximum Borrowing Capacity	400	[1]	'
Southeast Supply Header, LLC [Member]	'		'
Percentage of Subsidiary Contributed	'		24.95%
ArcLight group [Member]	'		'
Contributions to Pay Down Short-Term Debt	'		107
OGE Holdings [Member]	'		'
Contributions to Pay Down Short-Term Debt	'		9.1
OGE Energy [Member]	'		'
Percentage Share of Management Rights	'		50.00%
Limited Liability Company (LLC) or Limited Partnership (LP), Members or Limited Partners, Ownership Interest	28.50%		'
Percent of Incentive Distribution Rights	'		60.00%
Midstream Partnership [Member]	'		'
Line of Credit Facility, Maximum Borrowing Capacity	'		1,400
CenterPoint [Member]	'		'
Percentage Share of Management Rights	'		50.00%
Percent of Incentive Distribution Rights	'		40.00%

[1]	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.

Investment_in_Unconsolidated_A6

Investment in Unconsolidated Affiliates Related Party Transactions (Details) (USD $)

3 Months Ended

9 Months Ended

3 Months Ended

5 Months Ended

3 Months Ended

9 Months Ended

3 Months Ended

5 Months Ended

3 Months Ended

5 Months Ended

3 Months Ended

5 Months Ended

In Millions, unless otherwise specified

Sep. 30, 2013

Sep. 30, 2012

Sep. 30, 2013

Og and E [Member]

Operating Costs Charged [Member]

Natural Gas Transportation [Member]

Natural Gas Storage [Member]

Natural Gas Purchases [Member]

Og and E [Member]

Related Party Transaction [Line Items]

Distributions from unconsolidated affiliates

$17.40

Operating expenses

6.6

10.9

Related Party Transaction, Due from (to) Related Party

1.4

Electricity to power electric compression assets

3.9

5.2

Related Party Transaction, Purchases from Related Party

$8.70

$14.50

$3.10

$5.40

$9.40

[1]

$11.90

[1]

At SeptemberB 30, 2013, there was $1.4 million of natural gas purchases recorded for these activities.

Investment_in_Unconsolidated_A7

Investment in Unconsolidated Affiliates Summarized Balance Sheet Information of Equity Method Investment (Details) (USD $)	Sep. 30, 2013
In Millions, unless otherwise specified	Sep. 30, 2013
Summarized Balance Sheet Information of Equity Method Investment [Abstract]	'
Current assets	$427.50
Non-current assets	10,537.10
Current liabilities	622.1
Non-current liabilities	$2,140.40

Investment_in_Unconsolidated_A8

Investment in Unconsolidated Affiliates Summarized Income Statement of Equity Method Investment (Details) (USD $)	3 Months Ended	5 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2013
Summarized Income Statement of Equity Method Investment [Abstract]	'	'
Operating revenues	$796.40	$1,298.40
Gross margin	337.1	544.5
Operating income	132	206.7
Net income	$123.30	$188.40

Investment_in_Unconsolidated_A9

Investment in Unconsolidated Affiliates Reconciliation of Equity in Earnings of Unconsolidated Affiliates (Details) (USD $)	3 Months Ended		5 Months Ended	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2012
Equity Method Investments and Joint Ventures [Abstract]	'	'	'	'	'
OGE's 28.5% share of Enable Net Income	$35.10	'	$53.60	'	'
Amortization of basis difference	5.9	'	5.9	'	'
Elimination of Enogex Holdings fair value adjustments	5	'	5	'	'
Equity in earnings of unconsolidated affiliates (Note 1)	$46	$0	$64.50	$64.50	$0

Fair_Value_Measurements_Fair_V

Fair Value Measurements, Fair Value Hierarchy (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Securities Held as Collateral, at Fair Value	'	$0
Collateral Already Posted, Aggregate Fair Value	'	0.2
Fair Value, Inputs, Level 3 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Commodity Contract Assets	'	0
Fair Value, Measurements, Recurring [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Derivative Assets (Liabilities), at Fair Value, Net	0	'
Gas Imbalance Asset Fair Value Disclosure	'	3.1	[1],[2]
Gas Imbalance Liability Fair Value Disclosure	'	3.8	[1],[3]
Fair Value, Measurements, Recurring [Member] \| Estimate of Fair Value, Fair Value Disclosure [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Gas Imbalance Asset Fair Value Disclosure	'	3.1	[1],[2]
Gas Imbalance Liability Fair Value Disclosure	'	3.8	[1],[3]
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Gas Imbalance Asset Fair Value Disclosure	'	0	[1],[2]
Gas Imbalance Liability Fair Value Disclosure	'	0	[1],[3]
Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Gas Imbalance Asset Fair Value Disclosure	'	3.1	[1],[2]
Gas Imbalance Liability Fair Value Disclosure	'	3.8	[1],[3]
Fair Value, Measurements, Recurring [Member] \| Netting and Collateral [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Gas Imbalance Asset Fair Value Disclosure	'	0	[1],[2]
Gas Imbalance Liability Fair Value Disclosure	'	0	[1],[3]
Commodity Contract [Member] \| Fair Value, Measurements, Recurring [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Commodity Contract Assets	'	0.5
Commodity Contracts Liabilities	'	0.3
Commodity Contract [Member] \| Fair Value, Measurements, Recurring [Member] \| Estimate of Fair Value, Fair Value Disclosure [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Commodity Contract Assets	'	5.5
Commodity Contracts Liabilities	'	5.5
Commodity Contract [Member] \| Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 1 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Commodity Contract Assets	'	5
Commodity Contracts Liabilities	'	5
Commodity Contract [Member] \| Fair Value, Measurements, Recurring [Member] \| Fair Value, Inputs, Level 2 [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Commodity Contract Assets	'	0.5
Commodity Contracts Liabilities	'	0.5
Commodity Contract [Member] \| Fair Value, Measurements, Recurring [Member] \| Netting and Collateral [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Commodity Contract Assets	'	-5
Commodity Contracts Liabilities	'	-5.2
Portion Not Subject to Revaluation at Fair Market Value [Member]	'	'
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]	'	'
Fuel Reserves for Under Retained Fuel Due From Shippers	'	5.9
Fuel Reserves For Over Retained Fuel Due To Shippers	'	$1.20

[1]	The Company uses the market approach to fair value its gas imbalance assets and liabilities, using an average of the Inside FERC Gas Market Report for Panhandle Eastern Pipe Line Co. (Texas, Oklahoma Mainline), ONEOK (Oklahoma) and ANR Pipeline (Oklahoma) indices.
[2]	Gas imbalance assets exclude fuel reserves for under retained fuel due from shippers of $5.9 million at DecemberB 31, 2012, which fuel reserves are based on the value of natural gas at the time the imbalance was created and which are not subject to revaluation at fair market value.
[3]	Gas imbalance liabilities exclude fuel reserves for over retained fuel due to shippers of $1.2 million at DecemberB 31, 2012, which fuel reserves are based on the value of natural gas at the time the imbalance was created and which are not subject to revaluation at fair market value.

Fair_Value_Measurements_Carryi

Fair Value Measurements Carrying and Fair Value Amounts (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
OG&E Senior Notes [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Long-Term Debt, Carrying Amount	$2,154.30	$1,904.20
Long-Term Debt, Fair Value	2,455.20	2,401.60
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	10.4	10.7
Long-Term Debt, Fair Value	9.1	10
OGE Energy Senior Notes [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Long-Term Debt, Carrying Amount	99.9	99.9
Long-Term Debt, Fair Value	103.7	106.3
Enogex LLC Senior Notes [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Long-Term Debt, Carrying Amount	'	448.4	[1]
Long-Term Debt, Fair Value	'	493.4	[1]
Enogex LLC Term Loan [Member]	'	'
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]	'	'
Long-Term Debt, Carrying Amount	'	250	[1]
Long-Term Debt, Fair Value	'	$250	[1]

[1]	As a result of the formation of Enable Midstream Partners on May 1, 2013 and the Company's deconsolidation of Enogex Holdings, the Company's consolidated financial statements do not include any obligations for the Enogex LLC Senior Notes and Enogex LLC Term Loan as of May 1, 2013.

Derivative_Instruments_and_Hed2

Derivative Instruments and Hedging Activities, Quantitative Disclosures Related to Derivative Instruments (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012
Fair Value Hedging [Member]	'	'
Derivative [Line Items]	'	'
Fair Value Hedges, Net	$0	$0
Not Designated as Hedging Instrument [Member]	'	'
Derivative [Line Items]	'	'
Other Derivatives Not Designated as Hedging Instruments at Fair Value, Net	0	0
Cash Flow Hedging [Member]	'	'
Derivative [Line Items]	'	'
Cash Flow Hedges Derivative Instruments at Fair Value, Net	$0	'

Derivative_Instruments_and_Hed3

Derivative Instruments and Hedging Activities, Balance Sheet Presentation Related to Derivative Instruments (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012		Dec. 31, 2012	Dec. 31, 2012	Dec. 31, 2012	Dec. 31, 2012	Dec. 31, 2012	Dec. 31, 2012
In Millions, unless otherwise specified		Enogex [Member]		Enogex [Member]	Enogex [Member]	Enogex [Member]	Enogex [Member]	Enogex [Member]	Enogex [Member]
				Designated as Hedging Instrument [Member]	Designated as Hedging Instrument [Member]	Not Designated as Hedging Instrument [Member]	Not Designated as Hedging Instrument [Member]	Not Designated as Hedging Instrument [Member]	Not Designated as Hedging Instrument [Member]
					Natural gas [Member]		Natural gas [Member]	Natural gas [Member]	Natural gas [Member]
					Fixed Swaps/Futures [Member]		Fixed Swaps/Futures [Member]	Fixed Swaps/Futures [Member]	Physical [Member]
					Other Current Assets [Member]		Current PRM [Member]	Other Current Assets [Member]	Current PRM [Member]
Derivatives, Fair Value [Line Items]	'	'		'	'	'	'	'	'
Assets	$0	$5.50	[1]	$0	$0	$5.50	$0.10	$5	$0.40
Liabilities	'	$5.50	[1]	$0.50	$0.50	$5	$0	$4.70	$0.30

[1]	See Note 4 for a reconciliation of the Company's total derivatives fair value to the Company's Condensed Consolidated Balance Sheet at DecemberB 31, 2012.

Derivative_Instruments_and_Hed4

Derivative Instruments and Hedging Activities, Income Statement Presentation Related to Derivative Instruments (Details) (USD $)

Sep. 30, 2013

Sep. 30, 2012

In Millions, unless otherwise specified

Enogex [Member]

OGE Energy Corp. [Member]

Cash Flow Hedging [Member]

Not Designated as Hedging Instrument [Member]

Natural gas [Member]

Sales [Member]

Interest Rate Swap [Member]

Fixed Swaps/Futures [Member]

Natural gas [Member]

Cash Flow Hedging [Member]

Not Designated as Hedging Instrument [Member]

Physical [Member]

Not Designated as Hedging Instrument [Member]

Derivative Instruments, Gain (Loss) [Line Items]

Amount Recognized in Other Comprehensive Income

($0.80)

($1)

($0.80)

($1)

Amount Reclassifed from Accumulated Other Comprehensive Income (Loss) into Income

-0.1

4.9

5.2

-0.1

-0.3

Amount Recognized in Income

-2.9

-8

-0.2

0.8

-2.7

-8.8

Derivative Instruments With Credit Risk Related Contingent Features

StockBased_Compensation_Detail

Stock-Based Compensation (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, except Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Income tax benefit	$0.70	$1	$2.60	$3.20
Stock-Based Compensation Activity	'	'	'	'
Number of shares issued	'	'	125,264	'
Cash Received from Exercise of Stock Options	0	'	1.4	'
Tax Benefit Realized from Exercise of Stock Options	0	'	0	'
2013 Performance Units Grants [Member]	'	'	'	'
Stock-Based Compensation Activity	'	'	'	'
Number of shares granted	91,390	'	'	'
Performance Shares [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Compensation expense	3.1	2.6	8.3	7.7
Restricted Stock [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Compensation expense	0.1	0.1	0.3	0.5
Stock Compensation Plan [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Compensation expense	3.2	2.7	8.6	8.2
Less: Amount paid by unconsolidated affiliates	1.4	0	2	0
Net compensation expense	1.8	2.7	6.6	8.2
2012 Performance Unit Grants [Member]	'	'	'	'
Stock-Based Compensation Activity	'	'	'	'
Number of shares granted	82,400	'	'	'
Common Stock	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures	-292	'	549,228	'
Restricted Stock [Member]	'	'	'	'
Stock-Based Compensation Activity	'	'	'	'
Shares Paid for Tax Withholding for Share Based Compensation	4,038	'	10,512	'
Treasury Stock [Member]	'	'	'	'
Stock-Based Compensation Activity	'	'	'	'
Number of shares issued	0	'	'	'
Total Shareholder Return [Member] \| 2013 Performance Units Grants [Member]	'	'	'	'
Stock-Based Compensation Activity	'	'	'	'
Number of shares granted	45,596	'	'	'
Fair value of shares granted	$25.89	'	'	'
Total Shareholder Return [Member] \| Performance Shares [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Compensation expense	2.5	1.9	6.4	5.7
Total Shareholder Return [Member] \| 2012 Performance Unit Grants [Member]	'	'	'	'
Stock-Based Compensation Activity	'	'	'	'
Number of shares granted	41,288	'	'	'
Fair value of shares granted	$47.71	'	'	'
Performance Units Related to Earnings Per Share [Member] \| 2013 Performance Units Grants [Member]	'	'	'	'
Stock-Based Compensation Activity	'	'	'	'
Number of shares granted	45,794	'	'	'
Fair value of shares granted	$26.73	'	'	'
Performance Units Related to Earnings Per Share [Member] \| Performance Shares [Member]	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'
Compensation expense	$0.60	$0.70	$1.90	$2
Performance Units Related to Earnings Per Share [Member] \| 2012 Performance Unit Grants [Member]	'	'	'	'
Stock-Based Compensation Activity	'	'	'	'
Number of shares granted	41,112	'	'	'
Fair value of shares granted	$34.94	'	'	'

Income_Taxes_Details

Income Taxes (Details) (USD $)	3 Months Ended	9 Months Ended		3 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013
	Sep. 30, 2013	FIN 48 [Member]	FIN 48 reserve, net of tax [Member]	Federal operating loss [Member]
Income Tax Reconciliation, Tax Contingencies, State and Local	'	$7.80	$5.10	'
Reduction in income tax expense related to the Midstream Partnership	3.9	'	'	'
Increase in income tax expense related to deconsolidation	3.9	'	'	'
Net Operating Loss Carryforwards Utilized	'	'	'	122
Deferred Income Tax Expense (Benefit)	$17.10	'	'	'

Common_Equity_Forward_Stock_Sp

Common Equity Forward Stock Split (Details)	Sep. 30, 2013	Dec. 31, 2012
In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Common Stock, Shares Authorized	450	225

Common_Equity_Automatic_Divide

Common Equity Automatic Dividend Reinvestment and Stock Purchase Plan (Details) (USD $)	9 Months Ended		3 Months Ended	9 Months Ended
In Millions, except Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2013
	Sep. 30, 2013	Sep. 30, 2012	Automatic Dividend Reinvestment and Stock Purchase Plan [Member]	Automatic Dividend Reinvestment and Stock Purchase Plan [Member]
Stock Issued During Period, Shares, Dividend Reinvestment Plan and Stock Purchase Plan	'	'	105,595	304,385
Proceeds From Issuance of Shares Under Dividend Reinvestment Plan And Stock Purchase Plan	$10.80	$10.90	$4	$10.40
Shares Held in Reserve Related to Dividend Reinvestment Plan and Stock Purchase Plan	'	'	3,940,603	3,940,603

Common_Equity_Earnings_Per_Sha

Common Equity Earnings Per Share (Details) (USD $)	3 Months Ended		9 Months Ended
In Millions, except Per Share data, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Equity [Abstract]	'	'	'	'
Net Income Attributable to OGE Energy	$215.20	$185.50	$330	$316.50
Basic average common shares outstanding	198.4	197.4	198.1	197
Contingently issuable shares (performance units)	1.3	0.9	1.2	0.9
Diluted average common shares outstanding	199.7	198.3	199.3	197.9
Earnings Per Share, Basic and Diluted [Abstract]	'	'	'	'
Basic Earnings Per Average Common Share Attributable to OGE Energy Common Shareholders	$1.08	$0.94	$1.67	$1.61
Diluted Earnings Per Average Common Share Attributable to OGE Energy Common Shareholders	$1.08	$0.94	$1.66	$1.60
Anti-dilutive shares excluded from earnings per share calculation	0	0	0	0

LongTerm_Debt_Details

Long-Term Debt (Details) (USD $)	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013
Debt Instrument [Line Items]	'
Percent of Principal Amount Subject to Optional Tender	100.00%
Garfield Industrial Authority Bond [Member]	'
Debt Instrument [Line Items]	'
Date Due	1-Jan-25
Muskogee Industrial Authority Bond Due 2025 [Member]	'
Debt Instrument [Line Items]	'
Date Due	1-Jan-25
Muskogee Industrial Authority Bond Due 2027 [Member]	'
Debt Instrument [Line Items]	'
Date Due	1-Jun-27
Redeemable during the next 12 months	'
Debt Instrument [Line Items]	'
Long-term debt	135.4
Redeemable during the next 12 months \| Garfield Industrial Authority Bond [Member]	'
Debt Instrument [Line Items]	'
Series Minimum	0.18%
Series Maximum	0.34%
Redeemable during the next 12 months \| Muskogee Industrial Authority Bond Due 2025 [Member]	'
Debt Instrument [Line Items]	'
Series Minimum	0.12%
Series Maximum	0.39%
Redeemable during the next 12 months \| Muskogee Industrial Authority Bond Due 2027 [Member]	'
Debt Instrument [Line Items]	'
Series Minimum	0.11%
Series Maximum	0.30%
OG&E [Member] \| Redeemable during the next 12 months \| Garfield Industrial Authority Bond [Member]	'
Debt Instrument [Line Items]	'
Long term debt, gross	47
OG&E [Member] \| Redeemable during the next 12 months \| Muskogee Industrial Authority Bond Due 2025 [Member]	'
Debt Instrument [Line Items]	'
Long term debt, gross	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, gross	56
Senior Notes [Member] \| OG&E [Member] \| Series due May 1, 2043 [Member]	'
Debt Instrument [Line Items]	'
Long term debt, gross	250
Debt Instrument, Interest Rate, Stated Percentage	3.90%
Date Due	1-May-43

ShortTerm_Debt_and_Credit_Faci2

Short-Term Debt and Credit Facilities (Details) (USD $)	Sep. 30, 2013		Dec. 31, 2012	Sep. 30, 2013		Sep. 30, 2013		1-May-13	Sep. 30, 2013
In Millions, unless otherwise specified	Sep. 30, 2013		Dec. 31, 2012	OGE Energy [Member]		OG&E [Member]		Midstream Partnership [Member]	Enogex LLC [Member]
Line of Credit Facility [Line Items]	'		'	'		'		'	'
Short-term debt	$447		$430.90	'		'		'	'
Line of Credit Facility [Abstract]	'		'	'		'		'	'
Aggregate Commitment	1,150		'	750	[1]	400	[2]	1,400	400	[2]
Amount Outstanding	449.1	[3]	'	447	[1],[3]	2.1	[2],[3]	'	'
Total	1,150	[4]	'	'		'		'	'
Weighted Average Interest Rate	0.30%		'	0.30%	[1],[5]	0.53%	[2],[5]	'	'
Maturity	'		'	13-Dec-17	[6]	13-Dec-17	[6]	'	'
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]	This bank facility is available to back up OGE Energy's commercial paper borrowings and to provide revolving credit borrowings. This bank facility can also be used as a letter of credit facility.
[2]	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.
[3]	Includes direct borrowings under the revolving credit agreements, commercial paper borrowings and letters of credit at SeptemberB 30, 2013.
[4]	Effective May 1, 2013, Enable Midstream Partners entered into a $1.4 billion, five-year senior unsecured revolving credit facility in accordance with the terms of the Master Formation Agreement and Enogex LLC's $400 million revolving credit facility was terminated.
[5]	Represents the weighted-average interest rate for the outstanding borrowings under the revolving credit agreements, commercial paper borrowings and letters of credit.
[6]	In December 2011, the Company and OG&E entered into unsecured five-year revolving credit agreements to total in the aggregate $1,150.0 million ($750 million for the Company and $400 million for OG&E). Each of the credit facilities contain an option, which may be exercised up to two times, to extend the term for an additional year, subject to consent of a specified percentage of the lenders. Effective July 29, 2013, the Company and OG&E utilized one of these one-year extensions, and received consent from all of the lenders, to extend the maturity of their credit agreements to December 13, 2017.

Retirement_Plans_and_Postretir2

Retirement Plans and Postretirement Benefit Plans (Details) (USD $)	3 Months Ended				9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013		Sep. 30, 2012		Sep. 30, 2013		Sep. 30, 2012
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]	'		'		'		'
Defined Benefit Plans, Estimated Future Employer Contributions in Next Fiscal Year	$35		'		'		'
Defined Benefit Plan, Contributions by Employer	35		'		'		'
Pension Plans, Defined Benefit [Member]	'		'		'		'
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]	'		'		'		'
Net periodic benefit cost (net of unconsolidated affiliates)	5.4		7.7		18.4		23
Pension Plan [Member]	'		'		'		'
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]	'		'		'		'
Service cost	4.8		4.5		14.3		13.5
Interest cost	6.6		7.5		20		22.5
Expected return on plan assets	-12.1		-11.5		-36.3		-34.5
Amortization of net loss	6.6		6		19.8		17.9
Amortization of unrecognized prior service cost	0.5	[1]	0.5	[1]	1.4	[1]	1.6	[1]
Total net periodic benefit cost	6.4		7		19.2		21
Less: Amount paid by unconsolidated affiliates	1.5		0		2.5		0
Net periodic benefit cost (net of unconsolidated affiliates)	4.9	[2]	7	[2]	16.7	[3]	21	[3]
Capitalized Portion of Net Periodic Benefit Cost	1.1		1.6		3.7		4.7
Restoration of Retirement Income Plan [Member]	'		'		'		'
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]	'		'		'		'
Service cost	0.3		0.3		0.9		0.8
Interest cost	0.1		0.1		0.4		0.4
Expected return on plan assets	0		0		0		0
Amortization of net loss	0.1		0.1		0.3		0.3
Amortization of unrecognized prior service cost	0.1	[1]	0.2	[1]	0.2	[1]	0.5	[1]
Total net periodic benefit cost	0.6		0.7		1.8		2
Less: Amount paid by unconsolidated affiliates	0.1		0		0.1		0
Net periodic benefit cost (net of unconsolidated affiliates)	0.5	[2]	0.7	[2]	1.7	[3]	2	[3]
Postretirement Benefit Plan [Member]	'		'		'		'
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]	'		'		'		'
Service cost	1.1		1		3.3		3.1
Interest cost	2.5		2.9		7.7		8.9
Expected return on plan assets	-0.6		-0.8		-1.9		-2.3
Amortization of transition obligation	0		0.7		0		2.1
Amortization of net loss	5.4		5.2		16.1		15.4
Amortization of unrecognized prior service cost	-4.1	[1]	-4.1	[1]	-12.4	[1]	-12.4	[1]
Total net periodic benefit cost	4.3		4.9		12.8		14.8
Less: Amount paid by unconsolidated affiliates	0.6		0		1		0
Net periodic benefit cost (net of unconsolidated affiliates)	3.7	[4]	4.9	[4]	11.8	[5]	14.8	[5]
Capitalized Portion of Net Periodic Benefit Cost	0.7		1		2.3		3
OKLAHOMA \| Pension Plans, Defined Benefit [Member]	'		'		'		'
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]	'		'		'		'
Additional Pension Expense to Meet State Requirements	1.5		1.9		4.6		7.6
OKLAHOMA \| Postretirement Benefit Plan [Member]	'		'		'		'
Defined Benefit Plan, Net Periodic Benefit Cost [Abstract]	'		'		'		'
Additional Pension Expense to Meet State Requirements	$0.10		$0.10		$0.40		$0.80

[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]	In addition to the $5.4 million and $7.7 million of net periodic benefit cost recognized during the three months ended SeptemberB 30, 2013 and 2012, respectively, OG&E recognized an increase in pension expense during the three months ended SeptemberB 30, 2013 and 2012 of $1.5 million and $1.9 million, respectively, to maintain the allowable amount to be recovered for pension expense in the Oklahoma jurisdiction which are included in the Pension tracker regulatory liability (see Note 1).
[3]	In addition to the $18.4 million and $23.0 million of net periodic benefit cost recognized during the nine months ended SeptemberB 30, 2013 and 2012, respectively, OG&E recognized an increase in pension expense during the nine months ended SeptemberB 30, 2013 and 2012 of $4.6 million and $7.6 million, respectively, to maintain the allowable amount to be recovered for pension expense in the Oklahoma jurisdiction which are included in the Pension tracker regulatory liability (see Note 1).
[4]	In addition to the $3.7 million and $4.9 million of net periodic benefit cost recognized during the three months ended SeptemberB 30, 2013 and 2012, respectively, OG&E recognized an increase in postretirement medical expense during the three months ended SeptemberB 30, 2013 and 2012 of $0.1 million and $0.1 million, respectively, to maintain the allowable amount to be recovered for postretirement medical expense in the Oklahoma jurisdiction which are included in the Pension tracker regulatory liability (see Note 1).
[5]	In addition to the $11.8 million and $14.8 million of net periodic benefit cost recognized during the nine months ended SeptemberB 30, 2013 and 2012, respectively, OG&E recognized an increase in postretirement medical expense during the nine months ended SeptemberB 30, 2013 and 2012 of $0.4 million and $0.8 million, respectively, to maintain the allowable amount to be recovered for postretirement medical expense in the Oklahoma jurisdiction which are included in the Pension tracker regulatory liability (see Note 1).

Report_of_Business_Segments_De

Report of Business Segments (Details) (USD $)	3 Months Ended		5 Months Ended	9 Months Ended
In Millions, unless otherwise specified	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Segment Reporting Information [Line Items]	'	'	'	'	'	'
Operating revenues	$723.20	$1,113.40	'	$2,358.80	$2,809.10	'
Cost of goods sold	273	539.6	'	1,196.60	1,434.20	'
Gross margin on revenues	450.2	573.8	'	1,162.20	1,374.90	'
Other operation and maintenance	102.2	147.1	'	372.2	447.7	'
Depreciation and amortization	65.4	93	'	231.7	270.1	'
Impairment of assets	0	0	'	0	0.3	'
Gain on insurance proceeds	0	0	'	0	-7.5	'
Taxes other than income	21.7	29.7	'	78.1	84.7	'
Operating income (loss)	260.9	304	'	480.2	579.6	'
Equity in earnings of unconsolidated affiliates	46	0	64.5	64.5	0	'
Investment in unconsolidated affiliates	1,295.80	'	1,295.80	1,295.80	'	0
Total assets	9,144.20	9,706	9,144.20	9,144.20	9,706	9,922.20
Electric Utility [Member]	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'
Operating revenues	723.2	721	'	1,753.30	1,675.70	'
Cost of goods sold	273	271.8	'	733.6	671.9	'
Gross margin on revenues	450.2	449.2	'	1,019.70	1,003.80	'
Other operation and maintenance	105.9	108.6	'	318	333.9	'
Depreciation and amortization	62.5	63.5	'	185.8	185.9	'
Impairment of assets	'	'	'	'	0	'
Gain on insurance proceeds	'	'	'	'	0	'
Taxes other than income	20.8	19.1	'	63.9	58.4	'
Operating income (loss)	261	258	'	452	425.6	'
Equity in earnings of unconsolidated affiliates	0	'	'	0	'	'
Investment in unconsolidated affiliates	0	'	0	0	'	'
Total assets	7,704	7,082.30	7,704	7,704	7,082.30	'
Natural Gas Midstream Operations [Member]	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'
Operating revenues	0	412.4	'	630.4	1,186	'
Cost of goods sold	0	288.6	'	489	816.5	'
Gross margin on revenues	0	123.8	'	141.4	369.5	'
Other operation and maintenance	0	42.3	'	60.9	127.3	'
Depreciation and amortization	0	26.5	'	36.8	74.2	'
Impairment of assets	'	'	'	'	0.3	'
Gain on insurance proceeds	'	'	'	'	-7.5	'
Taxes other than income	0	9.8	'	10.5	22.8	'
Operating income (loss)	0	45.2	'	33.2	152.4	'
Equity in earnings of unconsolidated affiliates	46	'	'	64.5	'	'
Investment in unconsolidated affiliates	1,295.80	'	1,295.80	1,295.80	'	'
Total assets	1,311.30	2,562.70	1,311.30	1,311.30	2,562.70	'
Other Operations [Member]	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'
Operating revenues	0	0	'	0	0	'
Cost of goods sold	0	0	'	0	0	'
Gross margin on revenues	0	0	'	0	0	'
Other operation and maintenance	-3.7	-3.8	'	-6.7	-13.5	'
Depreciation and amortization	2.9	3	'	9.1	10	'
Impairment of assets	'	'	'	'	0	'
Gain on insurance proceeds	'	'	'	'	0	'
Taxes other than income	0.9	0.8	'	3.7	3.5	'
Operating income (loss)	-0.1	0	'	-6.1	0	'
Equity in earnings of unconsolidated affiliates	0	'	'	0	'	'
Investment in unconsolidated affiliates	0	'	0	0	'	'
Total assets	172.2	276.6	172.2	172.2	276.6	'
Eliminations [Member]	'	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'	'
Operating revenues	0	-20	'	-24.9	-52.6	'
Cost of goods sold	0	-20.8	'	-26	-54.2	'
Gross margin on revenues	0	0.8	'	1.1	1.6	'
Other operation and maintenance	0	0	'	0	0	'
Depreciation and amortization	0	0	'	0	0	'
Impairment of assets	'	'	'	'	0	'
Gain on insurance proceeds	'	'	'	'	0	'
Taxes other than income	0	0	'	0	0	'
Operating income (loss)	0	0.8	'	1.1	1.6	'
Equity in earnings of unconsolidated affiliates	0	'	'	0	'	'
Investment in unconsolidated affiliates	0	'	0	0	'	'
Total assets	($43.30)	($215.60)	($43.30)	($43.30)	($215.60)	'

Commitments_and_Contingencies_1

Commitments and Contingencies (Details) (USD $)	Sep. 30, 2013	Dec. 31, 2012	Mar. 31, 2014	Oct. 31, 2013	Oct. 31, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013	Sep. 30, 2013
			OG&E minimum fuel purchase commitments [Member]	OG&E minimum fuel purchase commitments [Member]	OG&E minimum fuel purchase commitments [Member]	OG&E long-term service agreement commitments [Member]	OG&E long-term service agreement commitments [Member]	Enogex [Member]	OG&E Wind Energy Purchase Power Lawsuit [Member]
						McClain Plant [Member]	Redbud Plant [Member]
Long-term Purchase Commitment [Line Items]	'	'	'	'	'	'	'	'	'
Percentage of OG&E's Projected 2013 Requirements	'	'	'	84.00%	26.10%	'	'	'	'
Percentage of OG&E's Projected 2014 Requirements	'	'	25.50%	'	'	'	'	'	'
Factored-Fired Hours	'	'	'	'	'	128,000	24,000	'	'
Factored-Fired Starts	'	'	'	'	'	3,600	'	'	'
Operating Leases, Future Minimum Payments Due	$0	'	'	'	'	'	'	'	'
Commitments and Contingencies	'	'	'	'	'	'	'	0	'
Loss Contingency, Damages Sought, Value	'	'	'	'	'	'	'	'	100,000
Loss Contingency, Range of Possible Loss, Minimum	'	'	'	'	'	'	'	'	0
Loss Contingency, Range of Possible Loss, Maximum	'	'	'	'	'	'	'	'	10,000,000
Estimated Environmental Capital Costs	1,000,000,000	'	'	'	'	'	'	'	'
Potential Penalty Under the Federal Clean Air Act	$37,500	'	'	'	'	'	'	'	'