Acquisition - Narrative (Details) a in Thousands, $ in Thousands		3 Months Ended
	Jan. 31, 2018 USD ($)	Mar. 31, 2019 USD ($) a MMBTU customer mi
Black Diamond Acquisition
Business Acquisition [Line Items]
Payments to acquire	$ 638,500
Length of pipeline | mi		160
Production per day | MMBTU		300
Black Diamond Acquisition
Business Acquisition [Line Items]
Dedicated acres | a		141
Number of customers | customer		6
Black Diamond Gathering LLC
Business Acquisition [Line Items]
Payment to expand acreage dedication		$ 24,100
Increase in duration of the acreage dedication		5 years
Black Diamond Gathering LLC | Black Diamond Acquisition
Business Acquisition [Line Items]
Payments to acquire	638,266
Payment to expand acreage dedication	24,120
Greenfield Member | Black Diamond Acquisition
Business Acquisition [Line Items]
Payments to acquire	318,600
Black Diamond Gathering LLC
Business Acquisition [Line Items]
Ownership interest, equity method		54.40%
Ownership promote		4.40%
Black Diamond Gathering LLC | Greenfield Member
Business Acquisition [Line Items]
Ownership interest, equity method		45.60%
Noble Member | Black Diamond Acquisition
Business Acquisition [Line Items]
Payments to acquire	$ 319,900