Reporting Segments - Reconciliation of Segment Operating Income (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Reconciliation of segment operating income to net income (loss):
Segment operating income (loss)	$ 7,796	$ 10,914
General and administrative expense	(4,749)	(5,165)
Unit-based compensation expense	(635)	(1,438)
Interest expense, net	(2,786)	(2,599)
Other income (expense)	46	(270)
Income tax expense	(46)
Net income (loss)	(374)	1,442
Production
Reconciliation of segment operating income to net income (loss):
Segment operating income (loss)	(3,101)	1,039
Midstream
Reconciliation of segment operating income to net income (loss):
Segment operating income (loss)	$ 10,897	$ 9,875