Investments (Details) - USD ($) $ in Thousands			3 Months Ended		7 Months Ended	9 Months Ended		15 Months Ended	24 Months Ended
	Nov. 22, 2016	Jul. 05, 2016	Sep. 30, 2017	Sep. 30, 2016	Jun. 30, 2017	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Jun. 30, 2017	Dec. 31, 2016	Nov. 30, 2016	Jun. 05, 2016
Schedule of Equity Method Investments [Line Items]
Capital investments			$ 117,699			$ 117,699		$ 117,699		$ 107,320
Earnout			4,049			4,049		4,049		$ 4,270
Earnings in equity investments			2,873	$ 1,124		4,397	$ 1,136
Amortization of intangible assets						10,204	10,345
Cash distributions						18,530	$ 4,815
Carnero Gathering LLC, Joint Venture
Schedule of Equity Method Investments [Line Items]
Ownership interest (as a percent)		50.00%
Payments to acquire interest in joint venture		$ 37,000				5,100		8,400	$ 8,400
Assumption of capital commitments in joint venture		$ 7,400
Capital investments			45,900			45,900		45,900
Agreement term		15 years
Earnings in equity investments			2,000			4,700
Cash distributions						5,300
Carnero Gathering LLC, Joint Venture | Customer Relationships
Schedule of Equity Method Investments [Line Items]
Intangible asset, fair value		$ 13,000
Amortization of intangible assets			200			600
Carnero Processing Joint Venture
Schedule of Equity Method Investments [Line Items]
Ownership interest (as a percent)	50.00%										50.00%
Payments to acquire interest in joint venture	$ 55,500				$ 15,800
Assumption of capital commitments in joint venture	24,500
Payments of capital commitments from joint venture						5,300
Capital investments	$ 48,000		71,800			71,800		$ 71,800
Earnings in equity investments			1,000			500
TPL South Tex Processing Company LP
Schedule of Equity Method Investments [Line Items]
Ownership interest (as a percent)	50.00%	50.00%
SN Midstream | Carnero Gathering LLC, Joint Venture
Schedule of Equity Method Investments [Line Items]
Capital investments												$ 26,000
Earnout payments			$ 0			$ 0