UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF PARTNERS' CAPITAL - USD ($) $ in Thousands	Total	Adjustment	Noncontrolling interest	Noncontrolling interest Adjustment	Common	Common Adjustment	General Partner	General Partner Adjustment	Limited partners, Series A Preferred Units	Limited partners, Series A Preferred Units Adjustment
Beginning balance at Dec. 31, 2016	$ 1,169,673		$ 11,247		$ 1,129,132		$ 29,294
Net income (loss)	10,663		191		6,029		4,443
Distributions to unitholders	(89,029)		0		(83,044)		(5,985)
Unit-based compensation	3,919		0		3,919		0
Tax withholdings on vested SMLP LTIP awards	(2,051)		0		(2,051)		0
ATM Program issuances, net of costs	17,259		0		17,259		0
Contribution from General Partner	465		0		0		465
Ending balance at Jun. 30, 2017	1,110,899		11,438		1,071,244		28,217
January 1, 2018 impact of Topic 606day 1 adoption	4,214		0		4,130		84		$ 0
Beginning balance at Dec. 31, 2017	1,389,669	$ 1,393,883	10,813	$ 10,813	1,056,510	$ 1,060,640	27,920	$ 28,004	294,426	$ 294,426
Net income (loss)	(53,758)		143		(71,349)		3,198		14,250
Distributions to unitholders	(104,519)		0		(84,204)		(6,065)		(14,250)
Unit-based compensation	3,983		0		3,983		0		0
Tax withholdings on vested SMLP LTIP awards	(1,840)		0		(1,840)		0		0
Other	(941)		0		(131)		0		(810)
Ending balance at Jun. 30, 2018	$ 1,236,808		$ 10,956		$ 907,099		$ 25,137		$ 293,616