Subsequent Events	9 Months Ended
Sep. 30, 2017
Subsequent Events [Abstract]
Subsequent Events	Subsequent Events The Company has evaluated the period after the balance sheet date, noting no subsequent events or transactions that required recognition or disclosure in the financial statements, other than as previously disclosed or noted below. Derivative instruments. In October 2017, the Company entered into a new swap for natural gas which settles based on Henry Hub. The commodity contract included a total notional amount of 730,000 MMBtu with a weighted average floor price of $3.07 per MMBtu which settles in 2018. This derivative instrument does not qualify for and was not designated as hedging instruments for accounting purposes. Lease obligations. On October 1, 2017, the Company executed an amendment to its office space lease agreement to extend its term to March 31, 2029 and to lease an additional 8,915 square feet of space within its current office building. This amendment increased the Company’s total future minimum rental commitments under non-cancelable leases for office space to $33.3 million. Under the terms of the amendment, the Company’s rental obligation for the new premises will begin upon occupancy of such premises for the purpose of conducting business therefrom, which is projected to be in April 2018 or earlier. Credit facility borrowing base. On October 17, 2017, the Lenders completed their regular semi-annual redetermination of the borrowing base of the Second Amended Credit Facility, resulting in the borrowing base and the aggregate elected commitment reaffirmed at $1,600.0 million and $1,150.0 million, respectively. The next redetermination of the Company’s borrowing base is scheduled for April 1, 2018. OMP LTIP phantom unit grant. On October 19, 2017 (the “Grant Date”), OMP granted awards under the OMP LTIP of 101,500 phantom units (collectively, the “Phantom Units,” and each a “Phantom Unit”) to certain employees of Oasis. Each Phantom Unit represents the right to receive, upon vesting of the award, a cash payment equal to the fair market value of one OMP common unit on the day prior to the date it vests (the “Vesting Date”). Award recipients are also entitled to Distribution Equivalent Rights (a “DER”) with respect to each Phantom Unit received. Each DER represents the right to receive, upon vesting of the award, a cash payment equal to the value of the distributions paid on one OMP common unit between the Grant Date and the applicable Vesting Date. Each award of Phantom Units vests in equal amounts each year over a three-year period, and compensation expense will be recognized over the requisite service period. Consent and Tenth Amendment to Second Amended and Restated Credit Agreement. On November 6, 2017, the Company entered into the Tenth Amendment (the “Amendment”) to the Oasis Credit Facility, pursuant to which the Lenders consented to (i) the termination of the limited recourse guaranty agreements by and between each of Beartooth DevCo LLC and Bobcat DevCo LLC (collectively, the “DevCos,” and each a “DevCo”) and Wells Fargo Bank, N.A., as administrative agent (the “Administrative Agent”), under the Oasis Credit Facility and (ii) the termination and release of each DevCo’s DevCo Mortgage (as defined in the Amendment). Further, OMS, in its capacity as the majority owner of each of the DevCos, entered into the Undertaking Agreements with the Administrative Agent pursuant to which OMS agreed to limitations on the activities of each DevCo, including, but not limited to, the incurrence of indebtedness, asset acquisitions or dispositions, investments, mergers, issuance of additional equity interests, creation of liens on any DevCo assets or entry into any agreement that would restrict or prohibit the granting of liens on any DevCo assets, loans or advances to other persons, entry into any transaction with an affiliate, formation of a subsidiary and entry into any swap or similar derivative transaction (the “DevCo Covenants”). OMS further agreed to cause corresponding amendments to the Limited Liability Company Agreement of each DevCo to implement the DevCo Covenants and to require unanimous member approval for any amendment to the DevCo Covenants. Assignment of contract for construction of natural gas processing plant. On November 6, 2017, OMS agreed to assign to Bighorn DevCo LLC an indirect, wholly-owned subsidiary of OMP, the construction of a second gas processing plant to support Oasis’s production. Pursuant to this assignment, Bighorn DevCo LLC has agreed to assume (i) a fixed price agreement for engineering, procurement and construction of a 200 million standard cubic feet per day natural gas processing plant (the “EPC Agreement” and “Gas Plant II,” respectively), (ii) title to Gas Plant II and the ancillary equipment being constructed under the EPC Agreement, and (iii) a master service agreement and work orders pursuant to which the contractor has agreed to provide mechanical refrigeration units to support Gas Plant II’s operation. In addition, OMP has agreed to reimburse OMS for all capital expenditures previously made under the EPC Agreement or otherwise in respect of Gas Plant II. Finally, the Gas Gathering, Compression, Processing, and Gas Lift Agreement by and among OPNA, OPM, OMS, and OMP, dated as of September 25, 2017, was amended to reflect the Gas Plant II’s additional processing capacity. OMP currently estimates that it will reimburse OMS approximately $66.7 million in connection with Gas Plant II.

Subsequent Events

The Company has evaluated the period after the balance sheet date, noting no subsequent events or transactions that required recognition or disclosure in the financial statements, other than as previously disclosed or noted below.

Derivative instruments. In October 2017, the Company entered into a new swap for natural gas which settles based on Henry Hub. The commodity contract included a total notional amount of 730,000 MMBtu with a weighted average floor price of $3.07 per MMBtu which settles in 2018. This derivative instrument does not qualify for and was not designated as hedging instruments for accounting purposes.

Lease obligations. On October 1, 2017, the Company executed an amendment to its office space lease agreement to extend its term to March 31, 2029 and to lease an additional 8,915 square feet of space within its current office building. This amendment increased the Company’s total future minimum rental commitments under non-cancelable leases for office space to $33.3 million. Under the terms of the amendment, the Company’s rental obligation for the new premises will begin upon occupancy of such premises for the purpose of conducting business therefrom, which is projected to be in April 2018 or earlier.

Credit facility borrowing base. On October 17, 2017, the Lenders completed their regular semi-annual redetermination of the borrowing base of the Second Amended Credit Facility, resulting in the borrowing base and the aggregate elected commitment reaffirmed at $1,600.0 million and $1,150.0 million, respectively. The next redetermination of the Company’s borrowing base is scheduled for April 1, 2018.

OMP LTIP phantom unit grant. On October 19, 2017 (the “Grant Date”), OMP granted awards under the OMP LTIP of 101,500 phantom units (collectively, the “Phantom Units,” and each a “Phantom Unit”) to certain employees of Oasis. Each Phantom Unit represents the right to receive, upon vesting of the award, a cash payment equal to the fair market value of one OMP common unit on the day prior to the date it vests (the “Vesting Date”). Award recipients are also entitled to Distribution Equivalent Rights (a “DER”) with respect to each Phantom Unit received. Each DER represents the right to receive, upon vesting of the award, a cash payment equal to the value of the distributions paid on one OMP common unit between the Grant Date and the applicable Vesting Date. Each award of Phantom Units vests in equal amounts each year over a three-year period, and compensation expense will be recognized over the requisite service period.

Consent and Tenth Amendment to Second Amended and Restated Credit Agreement. On November 6, 2017, the Company entered into the Tenth Amendment (the “Amendment”) to the Oasis Credit Facility, pursuant to which the Lenders consented to (i) the termination of the limited recourse guaranty agreements by and between each of Beartooth DevCo LLC and Bobcat DevCo LLC (collectively, the “DevCos,” and each a “DevCo”) and Wells Fargo Bank, N.A., as administrative agent (the “Administrative Agent”), under the Oasis Credit Facility and (ii) the termination and release of each DevCo’s DevCo Mortgage (as defined in the Amendment). Further, OMS, in its capacity as the majority owner of each of the DevCos, entered into the Undertaking Agreements with the Administrative Agent pursuant to which OMS agreed to limitations on the activities of each DevCo, including, but not limited to, the incurrence of indebtedness, asset acquisitions or dispositions, investments, mergers, issuance of additional equity interests, creation of liens on any DevCo assets or entry into any agreement that would restrict or prohibit the granting of liens on any DevCo assets, loans or advances to other persons, entry into any transaction with an affiliate, formation of a subsidiary and entry into any swap or similar derivative transaction (the “DevCo Covenants”). OMS further agreed to cause corresponding amendments to the Limited Liability Company Agreement of each DevCo to implement the DevCo Covenants and to require unanimous member approval for any amendment to the DevCo Covenants.

Assignment of contract for construction of natural gas processing plant. On November 6, 2017, OMS agreed to assign to Bighorn DevCo LLC an indirect, wholly-owned subsidiary of OMP, the construction of a second gas processing plant to support Oasis’s production. Pursuant to this assignment, Bighorn DevCo LLC has agreed to assume (i) a fixed price agreement for engineering, procurement and construction of a 200 million standard cubic feet per day natural gas processing plant (the “EPC Agreement” and “Gas Plant II,” respectively), (ii) title to Gas Plant II and the ancillary equipment being constructed under the EPC Agreement, and (iii) a master service agreement and work orders pursuant to which the contractor has agreed to provide mechanical refrigeration units to support Gas Plant II’s operation. In addition, OMP has agreed to reimburse OMS for all capital expenditures previously made under the EPC Agreement or otherwise in respect of Gas Plant II. Finally, the Gas Gathering, Compression, Processing, and Gas Lift Agreement by and among OPNA, OPM, OMS, and OMP, dated as of September 25, 2017, was amended to reflect the Gas Plant II’s additional processing capacity. OMP currently estimates that it will reimburse OMS approximately $66.7 million in connection with Gas Plant II.