XML 60 R60.htm IDEA: XBRL DOCUMENT
v3.3.0.814

Subsequent Events (Details) | 1 Months Ended | 9 Months Ended |  |  |  |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | --- | --- | ---
Oct. 31, 2015 USD ($) | Sep. 30, 2015 USD ($) MBbls | Nov. 05, 2015 MBbls | Oct. 30, 2015 MBbls $ / bbl | Oct. 06, 2015 USD ($) | Oct. 05, 2015 USD ($) | Oct. 01, 2015 USD ($) | Apr. 13, 2015 USD ($) | Apr. 12, 2015 USD ($) | Dec. 31, 2012
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |
Future obligations under cost sharing agreements | $ |  | $ 2,300,000 |  |  |  |  |  |  |  |
Subsequent Event [Member] |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |
Average swap price (in dollars per barrel) | $ / bbl |  |  |  | 52.19 |  |  |  |  |  |
Future obligations under cost sharing agreements | $ | $ 4,900,000 |  |  |  |  |  |  |  |  |
Revolving Credit Facility [Member] |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |
Line of credit facility maximum increase to aggregate commitments | $ |  |  |  |  |  |  |  | $ 1,700,000,000 | $ 2,000,000,000 |
Revolving Credit Facility [Member] | Subsequent Event [Member] |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |
Line of credit facility maximum increase to aggregate commitments | $ |  |  |  |  | $ 1,525,000,000.0 | $ 1,700,000,000 |  |  |  |
2015 Swaps [Member] | Subsequent Event [Member] |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |
Derivative, notional amount of oil (barrels) |  |  |  | 120 |  |  |  |  |  |
2016 Swaps [Member] | Subsequent Event [Member] |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |
Derivative, notional amount of oil (barrels) |  |  |  | 3,139 |  |  |  |  |  |
2017 Swaps [Member] | Subsequent Event [Member] |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |
Derivative, notional amount of oil (barrels) |  |  |  | 1,615 |  |  |  |  |  |
2018 Swaps [Member] | Subsequent Event [Member] |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |
Derivative, notional amount of oil (barrels) |  |  |  | 124 |  |  |  |  |  |
2019 Notes [Member] | Senior Unsecured Debt [Member] |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |
Stated interest rate |  |  |  |  |  |  |  |  |  | 7.25%
2021 Notes [Member] | Senior Unsecured Debt [Member] |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |
Stated interest rate |  |  |  |  |  |  |  |  |  | 6.50%
2023 Notes [Member] | Senior Unsecured Debt [Member] |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |
Stated interest rate |  |  |  |  |  |  |  |  |  | 6.875%
Drilling contracts [Member] |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |
Payments upon early contract termination | $ |  | $ 5,300,000 |  |  |  |  | $ 7,100,000 |  |  |
Williston Basin Project [Member] | Long Term Commitments [Member] | Crude oil [Member] |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |
Minimum quantity of delivery |  | 29,200 |  |  |  |  |  |  |  |
Williston Basin Project [Member] | Long Term Commitments [Member] | Crude oil [Member] | Subsequent Event [Member] |  |  |  |  |  |  |  |  |  |
Subsequent Event [Line Items] |  |  |  |  |  |  |  |  |  |
Minimum quantity of delivery |  |  | 7,100 |  |  |  |  |  |  |

X
- Definition Aggregate notional amount of derivative expressed in nonmonetary units. For example, the number of barrels specified in a fuel oil forward purchase contract. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Article 12 -Section 13 -Sentence Column B + Details
Name: | invest_DerivativeNonmonetaryNotionalAmount
Namespace Prefix: | invest_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | instant

X
- Definition Future Obligations Under Cost Sharing Agreements + References No definition available. + Details
Name: | oas_FutureObligationsUnderCostSharingAgreements
Namespace Prefix: | oas_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition The aggregate commitment may be increased to this amount by increasing the commitment of one or more lender(s) under the credit facility. + References No definition available. + Details
Name: | oas_LineOfCreditFacilityMaximumIncreaseToAggregateCommitments
Namespace Prefix: | oas_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Contractual interest rate for funds borrowed, under the debt agreement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DebtInstrumentInterestRateStatedPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Average fixed price related to the group of price risk swap derivatives. + References No definition available. + Details
Name: | us-gaap_DerivativeSwapTypeAverageFixedPrice
Namespace Prefix: | us-gaap_
Data Type: | us-types:perUnitItemType
Balance Type: | na
Period Type: | instant

X
- Definition Reflects the estimated amount of loss from the specified contingency as of the balance sheet date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14435-108349 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 9 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=25496072&loc=d3e14557-108349 + Details
Name: | us-gaap_LossContingencyEstimateOfPossibleLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Total amount of product committed to be supplied under existing contracts or agreements. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K (SK) -Number 229 -Section 1207 -Paragraph (a) -Subparagraph (2) + Details
Name: | us-gaap_OilAndGasDeliveryCommitmentsAndContractsRemainingContractualVolume
Namespace Prefix: | us-gaap_
Data Type: | num:volumeItemType
Balance Type: | na
Period Type: | instant

X
- Definition Detail information of subsequent event by type. User is expected to use existing line items from elsewhere in the taxonomy as the primary line items for this disclosure, which is further associated with dimension and member elements pertaining to a subsequent event. + References No definition available. + Details
Name: | us-gaap_SubsequentEventLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_SubsequentEventTypeAxis=us-gaap_SubsequentEventMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=us-gaap_RevolvingCreditFacilityMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeByNatureAxis=oas_TwoThousandFifteenSwapsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeByNatureAxis=oas_TwoThousandSixteenSwapsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeByNatureAxis=oas_TwoThousandSeventeenSwapsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DerivativeByNatureAxis=oas_TwoThousandEighteenSwapsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=oas_TwoThousandNineteenNotesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=us-gaap_UnsecuredDebtMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=oas_TwoThousandTwentyOneNotesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=oas_TwoThousandTwentyThreeNotesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LossContingenciesByNatureOfContingencyAxis=oas_DrillingContractsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ProductOrServiceAxis=oas_WillistonBasinProjectMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_SupplyCommitmentAxis=oas_LongTermCommitmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_EnergyAxis=us-gaap_CrudeOilMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |