XML 69 R56.htm IDEA: XBRL DOCUMENT
v3.5.0.2

Condensed Consolidating Financial Information - Additional Information (Details) | 6 Months Ended
--- | ---
Jun. 30, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract] |
Ownership percentage, guarantors (as percent) | 100.00%

X
- Definition Ownership percentage, guarantor + References No definition available. + Details
Name: | oas_OwnershipPercentageGuarantor
Namespace Prefix: | oas_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- References No definition available. + Details
Name: | us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration