Subsequent Events	12 Months Ended
Dec. 31, 2018
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 disclosed below. 2019 Capital Expenditures Arrangement On February 22, 2019, the Company entered into the MOU with OMP regarding the 2019 Capital Expenditures Arrangement, which outlines the funding of Bobcat DevCo’s expansion capital expenditures for the 2019 calendar year. As of December 31, 2018, OMS owned a 75% interest in Bobcat DevCo and OMP indirectly owned the remaining 25% interest. Pursuant to the Amended and Restated Limited Liability Company Agreement of Bobcat DevCo LLC, as amended (the “First A&R Bobcat LLCA”), OMS and OMP are each required to make pro-rata capital contributions to Bobcat DevCo in accordance with their respective percentage interests in Bobcat DevCo. Pursuant to the MOU, OMP agreed to make up to $80 million of the capital contributions to Bobcat DevCo that OMS would otherwise be required to contribute under the First A&R Bobcat LLCA. In connection with execution of the MOU, OMS and OMP have amended the First A&R Bobcat LLCA and entered into the Second Amended and Restated Limited Liability Company Agreement of Bobcat DevCo (the “Second A&R Bobcat LLCA”). The Second A&R Bobcat LLCA includes provisions applicable to the disproportionate capital contributions that OMP will make to Bobcat DevCo in connection with the 2019 Capital Expenditures Arrangement. Pursuant to the Second A&R Bobcat LLCA, upon the occurrence of a disproportionate capital contribution, OMS’s percentage interest and OMP’s percentage interest in Bobcat DevCo will be adjusted to take into account the amount of the disproportionate capital contribution and the fair market value of Bobcat DevCo’s assets at the time of any such contribution. Under the MOU, the Company and OMS have also agreed to a fair market value of Bobcat DevCo’s assets that will be used for the purposes of redetermining percentage interests in connection with the 2019 Capital Expenditures Arrangement. While the Second A&R Bobcat LLCA also contains provisions allowing a member to convert a disproportionate capital contribution to a pro-rata contribution in certain circumstances, OMS has agreed to waive its right to make such an election during the 2019 calendar year in the MOU. As a result of the 2019 Capital Expenditures Arrangement, the Company expects OMS’s percentage interest ownership in Bobcat DevCo to decrease from 75% to between approximately 64% and 66% by the end of the 2019 calendar year. The 2019 Capital Expenditures Arrangement did not have a material impact on the Company’s consolidated financial statements. Separate from the 2019 Capital Expenditures Arrangement and the agreements contained in the MOU, OMS and OMP may from time to time agree to fund certain special projects of Bobcat DevCo (“Bobcat Special Projects”) at ratios other than that reflected by their respective percentage interest ownership in Bobcat DevCo and without readjustments to their respective percentage interests. In general, OMP might agree to fund a Bobcat Special Project in excess of its pro-rata share of the relevant capital expenditures to the extent OMP expects to receive a disproportionate benefit from such capital expenditures. The Second A&R Bobcat LLCA also amended the First A&R Bobcat LLCA to include provisions related to the funding of any Bobcat Special Projects. The terms of the 2019 Capital Expenditures Arrangement were approved by the Board of Directors of the general partner of OMP following a unanimous recommendation for approval from the conflicts committee of the Board of Directors of the general partner of OMP, which consists entirely of independent directors. The conflicts committee was advised by Baird on financial matters and Richards, Layton & Finger, P.A. on legal matters. Oasis was advised by Vinson and Elkins L.L.P. on legal matters. Amended and restated bylaws On February 22, 2019, the Board of Directors amended and restated the Company’s bylaws to implement “proxy access” bylaw provisions. Under the new proxy access provisions, eligible shareholders, or an eligible group of up to 20 shareholders, owning 3% or more of the Company’s outstanding common stock continuously for at least three years will have the ability to nominate and include in the Company’s proxy materials for annual meetings occurring after the 2019 annual meeting qualifying director nominees constituting up to the greater of two directors and 20% of the number of directors currently serving on the Board, provided that the shareholder(s) and the nominee(s) satisfy the requirements specified in the amended and restated bylaws. This description is qualified in its entirety by reference to the text of the amended and restated bylaws, which is incorporated by reference as Exhibit 3.2 to this Annual Report on Form 10-K.

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 disclosed below.

2019 Capital Expenditures Arrangement

On February 22, 2019, the Company entered into the MOU with OMP regarding the 2019 Capital Expenditures Arrangement, which outlines the funding of Bobcat DevCo’s expansion capital expenditures for the 2019 calendar year. As of December 31, 2018, OMS owned a 75% interest in Bobcat DevCo and OMP indirectly owned the remaining 25% interest. Pursuant to the Amended and Restated Limited Liability Company Agreement of Bobcat DevCo LLC, as amended (the “First A&R Bobcat LLCA”), OMS and OMP are each required to make pro-rata capital contributions to Bobcat DevCo in accordance with their respective percentage interests in Bobcat DevCo.

Pursuant to the MOU, OMP agreed to make up to $80 million of the capital contributions to Bobcat DevCo that OMS would otherwise be required to contribute under the First A&R Bobcat LLCA. In connection with execution of the MOU, OMS and OMP have amended the First A&R Bobcat LLCA and entered into the Second Amended and Restated Limited Liability Company Agreement of Bobcat DevCo (the “Second A&R Bobcat LLCA”). The Second A&R Bobcat LLCA includes provisions applicable to the disproportionate capital contributions that OMP will make to Bobcat DevCo in connection with the 2019 Capital Expenditures Arrangement.

Pursuant to the Second A&R Bobcat LLCA, upon the occurrence of a disproportionate capital contribution, OMS’s percentage interest and OMP’s percentage interest in Bobcat DevCo will be adjusted to take into account the amount of the disproportionate capital contribution and the fair market value of Bobcat DevCo’s assets at the time of any such contribution. Under the MOU, the Company and OMS have also agreed to a fair market value of Bobcat DevCo’s assets that will be used for the purposes of redetermining percentage interests in connection with the 2019 Capital Expenditures Arrangement. While the Second A&R Bobcat LLCA also contains provisions allowing a member to convert a disproportionate capital contribution to a pro-rata contribution in certain circumstances, OMS has agreed to waive its right to make such an election during the 2019 calendar year in the MOU. As a result of the 2019 Capital Expenditures Arrangement, the Company expects OMS’s percentage interest ownership in Bobcat DevCo to decrease from 75% to between approximately 64% and 66% by the end of the 2019 calendar year. The 2019 Capital Expenditures Arrangement did not have a material impact on the Company’s consolidated financial statements.

Separate from the 2019 Capital Expenditures Arrangement and the agreements contained in the MOU, OMS and OMP may from time to time agree to fund certain special projects of Bobcat DevCo (“Bobcat Special Projects”) at ratios other than that reflected by their respective percentage interest ownership in Bobcat DevCo and without readjustments to their respective percentage interests. In general, OMP might agree to fund a Bobcat Special Project in excess of its pro-rata share of the relevant capital expenditures to the extent OMP expects to receive a disproportionate benefit from such capital expenditures. The Second A&R Bobcat LLCA also amended the First A&R Bobcat LLCA to include provisions related to the funding of any Bobcat Special Projects.

The terms of the 2019 Capital Expenditures Arrangement were approved by the Board of Directors of the general partner of OMP following a unanimous recommendation for approval from the conflicts committee of the Board of Directors of the general partner of OMP, which consists entirely of independent directors. The conflicts committee was advised by Baird on financial matters and Richards, Layton & Finger, P.A. on legal matters. Oasis was advised by Vinson and Elkins L.L.P. on legal matters.

Amended and restated bylaws

On February 22, 2019, the Board of Directors amended and restated the Company’s bylaws to implement “proxy access” bylaw provisions. Under the new proxy access provisions, eligible shareholders, or an eligible group of up to 20 shareholders, owning 3% or more of the Company’s outstanding common stock continuously for at least three years will have the ability to nominate and include in the Company’s proxy materials for annual meetings occurring after the 2019 annual meeting qualifying director nominees constituting up to the greater of two directors and 20% of the number of directors currently serving on the Board, provided that the shareholder(s) and the nominee(s) satisfy the requirements specified in the amended and restated bylaws. This description is qualified in its entirety by reference to the text of the amended and restated bylaws, which is incorporated by reference as Exhibit 3.2 to this Annual Report on Form 10-K.