UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF PARTNERS' CAPITAL - USD ($) $ in Thousands	Total	Noncontrolling interest	Common	General Partner	Limited partners, Series A Preferred Units
Beginning balance at Dec. 31, 2016	$ 1,169,673	$ 11,247	$ 1,129,132	$ 29,294
Net (loss) income	(583)	102	(2,777)	2,092
Distributions to unitholders	(44,452)	0	(41,464)	(2,988)
Unit-based compensation	2,048	0	2,048	0
Tax withholdings on vested SMLP LTIP awards	(2,051)	0	(2,051)	0
ATM Program issuances, net of costs	367	0	367	0
Contribution from General Partner	113	0	0	113
Ending balance at Mar. 31, 2017	1,125,115	11,349	1,085,255	28,511
January 1, 2018 impact of Topic 606day 1 adoption	4,214	0	4,130	84	$ 0
Beginning balance (Adjustment)	1,393,883	10,813	1,060,640	28,004	294,426
Beginning balance at Dec. 31, 2017	1,389,669	10,813	1,056,510	27,920	294,426
Net (loss) income	(3,845)	85	(13,113)	2,058	7,125
Distributions to unitholders	(45,053)	0	(42,024)	(3,029)	0
Unit-based compensation	1,979	0	1,979	0	0
Tax withholdings on vested SMLP LTIP awards	(1,943)	0	(1,943)	0	0
Other	(940)	0	(130)	0	(810)
Ending balance at Mar. 31, 2018	$ 1,344,081	$ 10,898	$ 1,005,409	$ 27,033	$ 300,741