XML 45 R75.htm IDEA: XBRL DOCUMENT v2.4.0.6

Significant Concentrations - Schedule of Purchasers Accounted More than Ten Percent of Total Sales (Detail)	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Musket Corporation [Member]
Significant Concentrations [Line Items]
Percent of sales to total sales	10.00%			[1]		[1]
Texon L.P. [Member]
Significant Concentrations [Line Items]
Percent of sales to total sales		[1]	18.00%		19.00%
Plains All American Pipeline L.P. [Member]
Significant Concentrations [Line Items]
Percent of sales to total sales		[1]	16.00%		28.00%
Enserco Energy Inc. [Member]
Significant Concentrations [Line Items]
Percent of sales to total sales		[1]	15.00%			[1]
Whiting Petroleum Corporation [Member]
Significant Concentrations [Line Items]
Percent of sales to total sales		[1]		[1]	11.00%
[1] Not applicable as the sales to these purchasers did not account for more than 10% of the Company's total sales for such respective periods.

X

- Details

Name:	oas_SignificantConcentrationsLineItems
Namespace Prefix:	oas_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

X

- Definition

The percentage of net product revenue to total net revenue from the sale of goods as of year end.

+ References

No definition available.

+ Details

Name:	us-gaap_SalesRevenueGoodsNetPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant