XML 38 R76.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Common Stock - Additional Information (Details) (USD $) In Thousands, except Share data, unless otherwise specified | 12 Months Ended | 0 Months Ended
--- | --- | ---
Dec. 31, 2014 | Dec. 31, 2013 | Dec. 31, 2012 | Dec. 09, 2013
Class of Stock [Line Items] |  |  |  |
Common stock, par value (in usd per share) | $ 0.01 us-gaap_CommonStockParOrStatedValuePerShare | $ 0.01 us-gaap_CommonStockParOrStatedValuePerShare |  |
Shares issued, price per share |  |  |  | $ 44.94 us-gaap_SharesIssuedPricePerShare
Proceeds from issuance of common stock |  | $ 314,400 oas_ProceedsfromIssuanceofCommonStockNetofDiscountsandExpenses |  |
Principal payments on revolving credit facility | 455,570 us-gaap_RepaymentsOfLongTermLinesOfCredit | 264,430 us-gaap_RepaymentsOfLongTermLinesOfCredit | 0 us-gaap_RepaymentsOfLongTermLinesOfCredit |
Common Stock [Member] |  |  |  |
Class of Stock [Line Items] |  |  |  |
Issuance of common stock, shares |  |  |  | 7,000,000 us-gaap_StockIssuedDuringPeriodSharesNewIssues / us-gaap_StatementClassOfStockAxis = us-gaap_CommonStockMember
Common stock, par value (in usd per share) |  |  |  | $ 0.01 us-gaap_CommonStockParOrStatedValuePerShare / us-gaap_StatementClassOfStockAxis = us-gaap_CommonStockMember
Common Stock [Member] |  |  |  |
Class of Stock [Line Items] |  |  |  |
Issuance of common stock, shares |  | 7,000,000 us-gaap_StockIssuedDuringPeriodSharesNewIssues / us-gaap_StatementEquityComponentsAxis = us-gaap_CommonStockMember |  |
Proceeds from issuance of common stock |  | 70 oas_ProceedsfromIssuanceofCommonStockNetofDiscountsandExpenses / us-gaap_StatementEquityComponentsAxis = us-gaap_CommonStockMember |  |
Additional Paid-in Capital [Member] |  |  |  |
Class of Stock [Line Items] |  |  |  |
Proceeds from issuance of common stock |  | 314,300 oas_ProceedsfromIssuanceofCommonStockNetofDiscountsandExpenses / us-gaap_StatementEquityComponentsAxis = us-gaap_AdditionalPaidInCapitalMember |  |
Revolving Credit Facility [Member] |  |  |  |
Class of Stock [Line Items] |  |  |  |
Principal payments on revolving credit facility |  | $ 264,400 us-gaap_RepaymentsOfLongTermLinesOfCredit / us-gaap_LongtermDebtTypeAxis = us-gaap_RevolvingCreditFacilityMember |  |

X
- Definition Proceeds from Issuance of Common Stock, Net of Discounts and Expenses + References No definition available. + Details
Name: | oas_ProceedsfromIssuanceofCommonStockNetofDiscountsandExpenses
Namespace Prefix: | oas_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_ClassOfStockLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Face amount or stated value per share of common stock. + 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 210.5-02.29) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 30 -Article 5 + Details
Name: | us-gaap_CommonStockParOrStatedValuePerShare
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition The cash outflow for the settlement of obligation drawn from a contractual arrangement with the lender, including letter of credit, standby letter of credit and revolving credit arrangements, under which borrowings can be made up to a specific amount at any point in time with maturities due beyond one year or the operating cycle, if longer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 15 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3291-108585 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Glossary Financing Activities -URI http://asc.fasb.org/extlink&oid=6513228 + Details
Name: | us-gaap_RepaymentsOfLongTermLinesOfCredit
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount per share or per unit of equity securities issued by non-development stage entity. + References No definition available. + Details
Name: | us-gaap_SharesIssuedPricePerShare
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of new stock issued during the period. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644 Reference 3: http://www.xbrl.org/2003/role/presentationRef -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 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29, 30 -Article 5 + Details
Name: | us-gaap_StockIssuedDuringPeriodSharesNewIssues
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

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

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

X
- Details
Name: | us-gaap_StatementEquityComponentsAxis=us-gaap_AdditionalPaidInCapitalMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

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