UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Revenues:
Total revenues		$ 90,153	$ 100,187	$ 287,063	$ 331,281
Costs and expenses:
Cost of natural gas and NGLs		8,632	7,472	22,945	50,802
Operation and maintenance		22,168	26,231	65,131	74,771
General and administrative		10,561	10,029	39,908	38,979
Depreciation and amortization		29,505	27,443	88,801	82,044
Transaction costs		726	129	1,944	2,562
Gain on asset sales, net		(104)	(347)	(270)	(1,595)
Long-lived asset impairment				4,475	45,021
Goodwill impairment			16,211	0	16,211
Total costs and expenses		71,488	87,168	222,934	308,795
Other income		795	12	644	304
Interest expense		(19,018)	(23,462)	(64,836)	(68,547)
Gain on early extinguishment of debt		24,690		78,925	0
Income (loss) before income taxes and equity method investment income (loss)		25,132	(10,431)	78,862	(45,757)
Income tax benefit (expense)		(298)	(21)	104	(1,427)
Income (loss) from equity method investees		795	(677)	7,146	(1,197)
Net income (loss)		25,629	(11,129)	86,112	(48,381)
Net income (loss) attributable to noncontrolling interest			(10,340)	(3,274)	(37,251)
Net income (loss) attributable to limited partners		25,629	(789)	89,386	(11,130)
Deemed contribution on exchange of preferred units		54,945		54,945
Series A Preferred Units
Costs and expenses:
Net income (loss) attributable to limited partners		6,481	7,125	20,731	21,375
Deemed contribution on exchange of preferred units		54,945		54,945
Series A Preferred Units | Subsidiaries
Costs and expenses:
Net income (loss) attributable to limited partners		7,298		9,640
Common Units
Costs and expenses:
Net income (loss) attributable to limited partners		$ 66,795	$ (7,914)	$ 113,960	$ (32,505)
Net income (loss) per limited partner unit:
Basic (in dollars per share)		$ 1.29	$ (0.17)	$ 2.41	$ (0.72)
Diluted (in dollars per share)		$ 1.25	$ (0.17)	$ 2.34	$ (0.72)
Weighted-average limited partner units outstanding:
Basic (shares)	[1]	51,974	45,319	47,331	45,319
Diluted (shares)		53,650	45,319	48,782	45,319
Natural Gas, Gathering, Transportation, Marketing and Processing
Revenues:
Total revenues		$ 71,964	$ 80,968	$ 229,667	$ 243,039
Oil and Condensate
Revenues:
Total revenues		10,783	12,219	35,246	68,438
Product and Service, Other
Revenues:
Total revenues		$ 7,406	$ 7,000	$ 22,150	$ 19,804

[1] As a result of the GP Buy-In Transaction, our historical results are those of Summit Investments. The number of common units of 45.3 million as of September 30, 2019 represents those of Summit Investments and has been used for the earnings per unit calculations presented herein.