XML 64 R66.htm IDEA: XBRL DOCUMENT
v3.19.3.a.u2

Stock Based Compensation (Details) - USD ($) $ / shares in Units, $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2019 | Dec. 31, 2018 | Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |
Number of Shares Authorized |  | 7,400,000 |  |  |
Tax Benefit from Compensation Expense |  | $ 3.6 |  | $ 3.4 | $ 3.5
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward] |  |  |  |  |
Minimum payout range |  | 0.00% |  |  |
Maximum payout range |  | 200.00% |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] |  |  |  |  |
Total Compensation Cost Not yet Recognized |  | $ 11.0 |  |  |
Performance Units Related to Earnings Per Share [Member] |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted |  | 0 | [1] | 87,308 | 86,857
Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value |  | $ 0 |  | $ 31.03 | $ 34.83
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward] |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number |  | 155,171 |  | 251,825 |
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted |  | 0 | [1] | 87,308 | 86,857
Equity Instruments Other than Options, Converted in Period | [2] | (91,356) |  |  |
Equity Instruments Other than Options, Forfeited in Period |  | (5,298) |  |  |
Awards Other than Options, Fully Vested |  | 74,053 |  |  |
Equity Instruments Other than Options, Converted, Aggregrate Intrinsic Value |  | $ 7.2 |  |  |
Equity Instruments Other than Options, Vested in Period, Aggregate Intrinsic Value |  | 6.6 |  |  |
Equity Instruments Other than Options, Outstanding, Aggregrate Intrinsic Value |  | 11.5 |  |  |
Equity Instruments Other than Options, Fully Vested, Aggregrate Intrinsic Value |  | $ 4.7 |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] |  |  |  |  |
Equity Instruments Other than Options, Nonvested, Number, Beginning Balance |  | 160,469 |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted |  | 0 | [1] | 87,308 | 86,857
Equity Instruments Other than Options, Vested in Period |  | (74,053) |  |  |
Equity Instruments Other than Options, Forfeited in Period |  | (5,298) |  |  |
Equity Instruments Other than Options, Nonvested, Number, Ending Balance |  | 81,118 |  | 160,469 |
Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value |  | $ 31.03 |  | $ 32.82 |
Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value |  | 0 |  | $ 31.03 | $ 34.83
Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value |  | 34.83 |  |  |
Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value |  | $ 32.07 |  |  |
Awards Other than Options, Vested and Expected to Vest, Outstanding | [3] | 77,617 |  |  |
Fair Value of Vested Performance Units and Restricted Stock |  | $ 5.2 |  | $ 4.9 | $ 1.2
Total Compensation Cost Not yet Recognized |  | $ 0.8 |  |  |
Total Compensation Cost Not yet Recognized, Period for Recognition |  | 1 year |  |  |
Total Shareholder Return [Member] |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted |  | 208,647 | [1] | 261,916 | 260,570
Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value |  | $ 47.00 |  | $ 36.86 | $ 41.77
Expected Dividend Rate |  | 4.00% |  | 3.60% | 3.80%
Expected Volatility Rate |  | 17.00% |  | 19.00% | 19.90%
Risk Free Interest Rate |  | 2.47% |  | 2.38% | 1.44%
Expected Term |  | 2 years 10 months 9 days |  | 2 years 10 months 9 days | 2 years 9 months 18 days
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward] |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number |  | 664,817 |  | 755,480 |
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted |  | 208,647 | [1] | 261,916 | 260,570
Equity Instruments Other than Options, Converted in Period | [2] | (274,078) |  |  |
Equity Instruments Other than Options, Forfeited in Period |  | (25,232) |  |  |
Awards Other than Options, Fully Vested |  | 222,163 |  |  |
Equity Instruments Other than Options, Converted, Aggregrate Intrinsic Value |  | $ 19.8 |  |  |
Equity Instruments Other than Options, Vested in Period, Aggregate Intrinsic Value |  | 11.5 |  |  |
Equity Instruments Other than Options, Outstanding, Aggregrate Intrinsic Value |  | 35.4 |  |  |
Equity Instruments Other than Options, Fully Vested, Aggregrate Intrinsic Value |  | $ 22.8 |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] |  |  |  |  |
Equity Instruments Other than Options, Nonvested, Number, Beginning Balance |  | 481,402 |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted |  | 208,647 | [1] | 261,916 | 260,570
Equity Instruments Other than Options, Vested in Period |  | (222,163) |  |  |
Equity Instruments Other than Options, Forfeited in Period |  | (25,232) |  |  |
Equity Instruments Other than Options, Nonvested, Number, Ending Balance |  | 442,654 |  | 481,402 |
Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value |  | $ 41.43 |  | $ 39.17 |
Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value |  | 47.00 |  | $ 36.86 | $ 41.77
Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value |  | 41.76 |  |  |
Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value |  | $ 41.45 |  |  |
Awards Other than Options, Vested and Expected to Vest, Outstanding | [3] | 418,331 |  |  |
Fair Value of Vested Performance Units and Restricted Stock |  | $ 9.3 |  | $ 5.9 | $ 6.3
Total Compensation Cost Not yet Recognized |  | $ 8.7 |  |  |
Total Compensation Cost Not yet Recognized, Period for Recognition |  | 1 year 8 months 1 day |  |  |
Performance Shares [Member] |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |
Compensation Expense |  | $ 13.0 |  | 13.3 | 9.0
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] |  |  |  |  |
Total Compensation Cost Not yet Recognized |  | 9.5 |  |  |
Restricted Stock [Member] |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |
Compensation Expense |  | $ 0.9 |  | $ 0.1 | $ 0.1
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted |  | 75,929 |  | 826 | 3,145
Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value |  | $ 41.71 |  | $ 36.28 | $ 34.96
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward] |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number |  | 72,880 |  | 2,711 |
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted |  | 75,929 |  | 826 | 3,145
Equity Instruments Other than Options, Forfeited in Period |  | (3,599) |  |  |
Equity Instruments Other than Options, Vested in Period, Aggregate Intrinsic Value |  | $ 0.1 |  |  |
Equity Instruments Other than Options, Outstanding, Aggregrate Intrinsic Value |  | 3.2 |  |  |
Equity Instruments Other than Options, Fully Vested, Aggregrate Intrinsic Value |  | $ 2.4 |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward] |  |  |  |  |
Equity Instruments Other than Options, Nonvested, Number, Beginning Balance |  | 2,711 |  |  |
Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Granted |  | 75,929 |  | 826 | 3,145
Equity Instruments Other than Options, Vested in Period |  | (2,161) |  |  |
Equity Instruments Other than Options, Forfeited in Period |  | (3,599) |  |  |
Equity Instruments Other than Options, Nonvested, Number, Ending Balance |  | 72,880 |  | 2,711 |
Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value |  | $ 41.66 |  | $ 35.00 |
Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value |  | 41.71 |  | $ 36.28 | $ 34.96
Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value |  | 34.66 |  |  |
Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value |  | $ 41.78 |  |  |
Awards Other than Options, Vested and Expected to Vest, Outstanding | [3] | 54,102 |  |  |
Fair Value of Vested Performance Units and Restricted Stock |  | $ 0.1 |  | $ 0.1 | $ 0.1
Total Compensation Cost Not yet Recognized |  | $ 1.5 |  |  |
Total Compensation Cost Not yet Recognized, Period for Recognition |  | 1 year 11 months 23 days |  |  |
Stock Compensation Plan [Member] |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |
Compensation Expense, Net of Unconsolidated Affiliates |  | $ 13.9 |  | 13.4 | 9.1
Performance Units Related to Earnings Per Share [Member] | Performance Shares [Member] |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |
Compensation Expense |  | 4.3 |  | 5.1 | 1.4
Total Shareholder Return [Member] | Performance Shares [Member] |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |
Compensation Expense |  | $ 8.7 |  | $ 8.2 | $ 7.6
Common Stock [Member] |  |  |  |  |
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |
Stock Issued During Period, Shares, Share-based Compensation, Net of Forfeitures |  | 443,900 |  | 26,211 | 2,298
[1] | For performance units, this represents the target number of performance units granted. Actual number of performance units earned, if any, is dependent upon performance and may range from zero percent to 200 percent of the target.
[2] | These amounts represent performance units that vested at December 31, 2018 which were settled in February 2019.
[3] | The intrinsic value of the performance units based on total shareholder return and earnings per share is $22.8 million and $4.7 million, respectively. The intrinsic value of restricted stock units is $2.4 million.

X
- Definition Allocated Share-Based Compensation Expense, Net of Unconsolidated Affiliates + References No definition available. + Details
Name: | oge_AllocatedShareBasedCompensationExpenseNetOfUnconsolidatedAffiliates
Namespace Prefix: | oge_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Awards Other than Options, Fully Vested + References No definition available. + Details
Name: | oge_AwardsOtherThanOptionsFullyVested
Namespace Prefix: | oge_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Awards Other than Options, Vested and Expected to Vest + References No definition available. + Details
Name: | oge_AwardsOtherThanOptionsVestedAndExpectedToVest
Namespace Prefix: | oge_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Equity Instruments Other than Options, Converted, Aggregrate Intrinsic Value + References No definition available. + Details
Name: | oge_EquityInstrumentsOtherThanOptionsConvertedAggregrateIntrinsicValue
Namespace Prefix: | oge_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Equity Instruments Other than Options, Converted in Period + References No definition available. + Details
Name: | oge_EquityInstrumentsOtherThanOptionsConvertedInPeriod
Namespace Prefix: | oge_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Fair Value of Vested Performance Units and Restricted Stock + References No definition available. + Details
Name: | oge_FairValueOfVestedPerformanceUnitsAndRestrictedStock
Namespace Prefix: | oge_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Maximum payout range + References No definition available. + Details
Name: | oge_MaximumPayoutRange
Namespace Prefix: | oge_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Minimum payout range + References No definition available. + Details
Name: | oge_MinimumPayoutRange
Namespace Prefix: | oge_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of expense for award under share-based payment arrangement. Excludes amount capitalized. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5047-113901 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 14.F) -URI http://asc.fasb.org/extlink&oid=115993241&loc=d3e301413-122809 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(1)(i) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
Name: | us-gaap_AllocatedShareBasedCompensationExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of cost not yet recognized for nonvested award under share-based payment arrangement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
Name: | us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Weighted-average period over which cost not yet recognized is expected to be recognized for award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (i) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
Name: | us-gaap_EmployeeServiceShareBasedCompensationNonvestedAwardsTotalCompensationCostNotYetRecognizedPeriodForRecognition1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of tax benefit for recognition of expense of award under share-based payment arrangement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(1)(i) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
Name: | us-gaap_EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The number of equity-based payment instruments, excluding stock (or unit) options, that were forfeited during the reporting period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iv)(3) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Weighted average fair value as of the grant date of equity-based award plans other than stock (unit) option plans that were not exercised or put into effect as a result of the occurrence of a terminating event. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(3) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(1) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(i)-(ii) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Per share or unit weighted-average fair value of nonvested award under share-based payment arrangement. Excludes share and unit options. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(i)-(ii) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(2) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition The weighted average fair value as of grant date pertaining to an equity-based award plan other than a stock (or unit) option plan for which the grantee gained the right during the reporting period, by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash in accordance with the terms of the arrangement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(2)(iii)(2) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | duration

X
- Definition The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (f)(2)(iii) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (f)(2)(ii) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The risk-free interest rate assumption that is used in valuing an option on its own shares. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (f)(2)(iv) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Net number of non-option equity instruments granted to participants. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(iv)(1) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsGranted
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of equity instruments other than options outstanding, including both vested and non-vested instruments. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(ii) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c)(1)(i) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingNumber
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period. + References No definition available. + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsOutstandingRollForward
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of shares authorized for issuance under share-based payment arrangement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Intrinsic value of nonvested award under share-based payment arrangement. Excludes share and unit options. + References No definition available. + Details
Name: | us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueNonvested
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Intrinsic value of outstanding award under share-based payment arrangement. Excludes share and unit options. + References No definition available. + Details
Name: | us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueOutstanding
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Intrinsic value of vested award under share-based payment arrangement. Excludes share and unit options. + References No definition available. + Details
Name: | us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardEquityInstrumentsOtherThanOptionsAggregateIntrinsicValueVested
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Expected term of award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (f)(2)(i) -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB Topic 14.D.2) -URI http://asc.fasb.org/extlink&oid=115993241&loc=d3e301413-122809 + Details
Name: | us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number, after forfeiture, of shares or units issued under share-based payment arrangement. Excludes shares or units issued under employee stock ownership plan (ESOP). + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=109259400&loc=d3e21463-112644 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(28)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_AwardTypeAxis=oge_PerformanceUnitsRelatedToEarningsPerShareMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardTypeAxis=oge_TotalShareholderReturnMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardTypeAxis=us-gaap_PerformanceSharesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardTypeAxis=us-gaap_RestrictedStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardTypeAxis=us-gaap_StockCompensationPlanMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PlanNameAxis=oge_PerformanceUnitsRelatedToEarningsPerShareMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PlanNameAxis=oge_TotalShareholderReturnMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | oge_ShareBasedCompensationSharesIssuedReturnedAndCashRecievedFromExerciseAxis=us-gaap_CommonStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |