Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities:
Net income including non-controlling interests	$ 3,712	$ 23,825
Adjustments to reconcile net income including non-controlling interests to net cash provided by operating activities:
Depreciation, depletion and amortization	149,265	126,666
Impairment	93	2,682
Deferred income taxes	828	16,037
Derivative instruments	71,116	(56,075)
Equity-based compensation expenses	6,754	6,708
Deferred financing costs amortization and other	5,475	4,940
Working capital and other changes:
Change in accounts receivable, net	(5,708)	(22,478)
Change in inventory	(3,672)	(3,679)
Change in prepaid expenses	492	282
Change in other current assets	0	(110)
Change in long-term inventory and other assets	(315)	(4)
Change in accounts payable, interest payable and accrued liabilities	(244)	6,060
Change in other current liabilities	0	2,945
Change in other liabilities	563	0
Net cash provided by operating activities	228,359	107,799
Cash flows from investing activities:
Capital expenditures	(254,838)	(96,047)
Acquisitions	(520,728)	0
Derivative settlements	(36,974)	(7,960)
Advances from joint interest partners	(28)	(759)
Net cash used in investing activities	(812,568)	(104,766)
Cash flows from financing activities:
Proceeds from Revolving Credit Facilities	1,470,000	246,000
Principal payments on Revolving Credit Facilities	(875,000)	(241,000)
Deferred financing costs	(215)	0
Purchases of treasury stock	(6,021)	(5,419)
Distributions to non-controlling interests	(3,450)	0
Other	(90)	(55)
Net cash provided by (used in) financing activities	585,224	(474)
Increase in cash and cash equivalents	1,015	2,559
Cash and cash equivalents:
Beginning of period	16,720	11,226
End of period	17,735	13,785
Supplemental non-cash transactions:
Change in accrued capital expenditures	12,855	8,396
Change in asset retirement obligations	3,453	787
Issuance of shares in connection with the Permian Basin Acquisition	$ 371,220	$ 0

Change In Capital Expenditures Incurred But Not Yet Paid

No definition available.

Name:	oas_ChangeInCapitalExpendituresIncurredButNotYetPaid
Namespace Prefix:	oas_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The total of the component of interest expense representing the noncash expenses charged against earnings in the period to amortize the long-term deferred financing costs and other income (expense) included in net income that results in no cash inflows or outflows in the period. Includes noncash adjustments to reconcile net income (loss) to cash provided by (used in) operating activities that are not separately disclosed.

+ References

No definition available.