Long-Term Debt	9 Months Ended
Long-Term Debt	Sep. 30, 2020
Debt Disclosure [Abstract]
Long-Term Debt	Long-Term Debt The Partnership has a revolving credit facility among OMP Operating, as borrower, Wells Fargo Bank, N.A., as Administrative Agent (the “Administrative Agent”) and the lenders party thereto (as amended, the “Revolving Credit Facility”), which matures on September 25, 2022. The Revolving Credit Facility is available to fund working capital and to finance acquisitions and other capital expenditures of the Partnership. As of September 30, 2020, the aggregate commitments under the Revolving Credit Facility were $575.0 million. At September 30, 2020, the Partnership had $487.5 million of borrowings outstanding under the Revolving Credit Facility and a de minimis outstanding letter of credit, resulting in an unused borrowing capacity of $87.5 million. For the three and nine months ended September 30, 2020, the weighted average interest rate incurred on borrowings under the Revolving Credit Facility was 1.9% and 2.6%, respectively. The weighted average interest rate incurred on borrowings under the Revolving Credit Facility for the nine months ended September 30, 2020 excludes the Specified Default Interest (defined below). At December 31, 2019, the Partnership had $458.5 million of borrowings outstanding under the Revolving Credit Facility and a $1.7 million outstanding letter of credit. The unused portion of the Revolving Credit Facility is subject to a commitment fee ranging from 0.375% to 0.500%. The fair value of the Revolving Credit Facility approximates book value since borrowings under the Revolving Credit Facility bear interest at rates which are tied to current market rates. In the second quarter of 2020, the Partnership identified that a Control Agreement (as defined in the Revolving Credit Facility) had not been executed for a certain bank account before the account was initially funded with cash, which represented an event of default. In May 2020, the Partnership executed a Control Agreement with respect to the bank account, thereby completing the documentation required under the Revolving Credit Facility, and entered into a limited waiver of this past event of default with the Majority Lenders (as defined in the Revolving Credit Facility), which provided forbearance of additional interest owed (“Specified Default Interest”) of $28.0 million until the earlier of (i) November 10, 2020 and (ii) an additional event of default. The Specified Default Interest is included in interest expense, net of capitalized interest on the Partnership’s Condensed Consolidated Statement of Operations for the nine months ended September 30, 2020. No Specified Default Interest was recorded during the three months ended September 30, 2020. The Partnership and the Administrative Agent agreed to exclude the Specified Default Interest from the interest coverage ratio financial covenant calculation. On September 29, 2020, the Partnership and OMP Operating executed a Waiver, Discharge and Forgiveness Agreement and Forbearance Extension (the “Waiver and Forbearance Agreement”) to permanently waive payment of the Specified Default Interest, subject to certain conditions. Under the terms of the Waiver and Forbearance Agreement, the Administrative Agent and the lenders agreed to forbear from demanding payment of the Specified Default Interest until the earlier to occur of (i) an additional event of default and (ii) the occurrence of the maturity date provided for in the Senior Secured Superpriority Debtor-In-Possession Revolving Credit Agreement entered into on October 2, 2020, among Oasis Petroleum, the other parties party thereto, each of the lenders thereto and Wells Fargo Bank, N.A., as administrative agent and issuing bank. The effectiveness of the waiver, discharge and forgiveness of the Specified Default Interest is subject to certain conditions, namely, effectiveness of the Oasis Petroleum Restructuring Plan, as well as the maintenance of the material contracts between Oasis Petroleum and the Partnership or the Partnership’s subsidiaries. The Partnership was in compliance with the covenants under the Revolving Credit Facility at September 30, 2020.