Revenue - Minimum Volume Commitments (Details) $ in Thousands	Jun. 30, 2018 USD ($)
Minimum revenue amounts under the minimum volume commitments
Minimum revenue amounts	$ 1,449,426
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2018-07-01
Minimum revenue amounts under the minimum volume commitments
Minimum revenue amounts	67,281
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01
Minimum revenue amounts under the minimum volume commitments
Minimum revenue amounts	316,322
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Minimum revenue amounts under the minimum volume commitments
Minimum revenue amounts	151,171
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Minimum revenue amounts under the minimum volume commitments
Minimum revenue amounts	150,758
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Minimum revenue amounts under the minimum volume commitments
Minimum revenue amounts	150,758
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Minimum revenue amounts under the minimum volume commitments
Minimum revenue amounts	150,758
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Minimum revenue amounts under the minimum volume commitments
Minimum revenue amounts	462,378
Gathering And Compression Agreement
Minimum revenue amounts under the minimum volume commitments
Minimum revenue amounts	1,283,862
Gathering And Compression Agreement | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2018-07-01
Minimum revenue amounts under the minimum volume commitments
Minimum revenue amounts	67,281
Gathering And Compression Agreement | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01
Minimum revenue amounts under the minimum volume commitments
Minimum revenue amounts	150,758
Gathering And Compression Agreement | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01
Minimum revenue amounts under the minimum volume commitments
Minimum revenue amounts	151,171
Gathering And Compression Agreement | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01
Minimum revenue amounts under the minimum volume commitments
Minimum revenue amounts	150,758
Gathering And Compression Agreement | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01
Minimum revenue amounts under the minimum volume commitments
Minimum revenue amounts	150,758
Gathering And Compression Agreement | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01
Minimum revenue amounts under the minimum volume commitments
Minimum revenue amounts	150,758
Gathering And Compression Agreement | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01
Minimum revenue amounts under the minimum volume commitments
Minimum revenue amounts	462,378
Water Services Agreement
Minimum revenue amounts under the minimum volume commitments
Minimum revenue amounts	165,564
Water Services Agreement | Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-01-01
Minimum revenue amounts under the minimum volume commitments
Minimum revenue amounts	$ 165,564