Revenue - Minimum Volume Commitments (Details) $ in Thousands	Mar. 31, 2019 USD ($)
Minimum revenue amounts under the minimum volume commitments
Minimum revenue amounts	$ 1,843,852
Gathering And Compression Agreement
Minimum revenue amounts under the minimum volume commitments
Minimum revenue amounts	1,726,886
Water Services Agreement
Minimum revenue amounts under the minimum volume commitments
Minimum revenue amounts	116,966
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-04-01
Minimum revenue amounts under the minimum volume commitments
Minimum revenue amounts	$ 258,006
Expected timing of satisfaction period	9 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-04-01 | Gathering And Compression Agreement
Minimum revenue amounts under the minimum volume commitments
Minimum revenue amounts	$ 141,040
Expected timing of satisfaction period	9 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2019-04-01 | Water Services Agreement
Minimum revenue amounts under the minimum volume commitments
Minimum revenue amounts	$ 116,966
Expected timing of satisfaction period	9 months
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	$ 210,363
Expected timing of satisfaction period	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-01-01 | Gathering And Compression Agreement
Minimum revenue amounts under the minimum volume commitments
Minimum revenue amounts	$ 210,363
Expected timing of satisfaction period	12 months
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	$ 209,788
Expected timing of satisfaction period	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-01-01 | Gathering And Compression Agreement
Minimum revenue amounts under the minimum volume commitments
Minimum revenue amounts	$ 209,788
Expected timing of satisfaction period	12 months
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	$ 209,788
Expected timing of satisfaction period	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2022-01-01 | Gathering And Compression Agreement
Minimum revenue amounts under the minimum volume commitments
Minimum revenue amounts	$ 209,788
Expected timing of satisfaction period	12 months
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	$ 209,788
Expected timing of satisfaction period	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2023-01-01 | Gathering And Compression Agreement
Minimum revenue amounts under the minimum volume commitments
Minimum revenue amounts	$ 209,788
Expected timing of satisfaction period	12 months
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	$ 210,363
Expected timing of satisfaction period	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2024-01-01 | Gathering And Compression Agreement
Minimum revenue amounts under the minimum volume commitments
Minimum revenue amounts	$ 210,363
Expected timing of satisfaction period	12 months
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01
Minimum revenue amounts under the minimum volume commitments
Minimum revenue amounts	$ 535,756
Expected timing of satisfaction period
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01 | Gathering And Compression Agreement
Minimum revenue amounts under the minimum volume commitments
Minimum revenue amounts	$ 535,756
Expected timing of satisfaction period
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2025-01-01 | Water Services Agreement
Minimum revenue amounts under the minimum volume commitments
Expected timing of satisfaction period