Selected Quarterly Financial Information—Unaudited (Details) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017 USD ($) MBoe $ / shares	Sep. 30, 2017 USD ($) $ / shares	Jun. 30, 2017 USD ($) $ / shares	Mar. 31, 2017 USD ($) $ / shares	Dec. 31, 2016 USD ($) $ / shares	Sep. 30, 2016 USD ($) $ / shares	Jun. 30, 2016 USD ($) $ / shares	Mar. 31, 2016 USD ($) $ / shares	Dec. 31, 2017 USD ($) $ / shares	Dec. 31, 2016 USD ($) $ / shares	Dec. 31, 2015 USD ($) $ / shares
Interim Reporting [Line Items]
Total revenue	$ 95,442	$ 89,111	$ 120,524	$ 124,582	$ 56,712	$ 99,171	$ 40,569	$ 64,381	$ 429,659	$ 260,833	$ 392,924
Income (loss) from operations	23,013	26,216	57,840	65,015	(3,979)	39,316	(19,478)	11,610	172,084	27,469	(95,855)
Net income (loss)	19,362	22,034	54,174	61,583	(7,286)	37,535	(20,810)	10,749	157,153	20,188	(101,305)
Net income (loss) attributable to the general partner and common and subordinated units	16,779	21,388	53,518	60,460	(8,614)	36,219	(22,111)	8,943	152,145	14,437	$ (108,017)
Cash distributions declared and paid per limited partner unit
Total assets	1,576,451	1,246,070	1,250,086	1,199,722	1,128,827	1,137,232	1,126,830	1,045,843	1,576,451	1,128,827
Long-term debt	388,000	362,000	393,000	388,000	316,000	299,000	285,000	116,000	388,000	316,000
Total mezzanine equity	$ 322,422	$ 27,092	$ 27,085	$ 34,145	$ 54,015	$ 54,015	$ 54,001	$ 54,001	$ 322,422	$ 54,015
Reduction in production volume due to cap (in Mboe) | MBoe	1.0
Common Units
Net income (loss) attributable to common and subordinated units per unit (basic)
Per unit (basic) (in usd per share) | $ / shares	$ 0.15	$ 0.16	$ 0.33	$ 0.37	$ 0.01	$ 0.24	$ (0.08)	$ 0.09	$ 1.01	$ 0.26	$ (0.56)
Per unit (diluted) (in usd per share) | $ / shares	0.15	0.16	0.33	0.37	0.01	0.24	(0.08)	0.09	1.01	0.26	(0.56)
Cash distributions declared and paid per limited partner unit
Per unit (in usd per share) | $ / shares	0.3125	0.3125	0.2875	0.2875	0.2875	0.2875	0.2625	0.2625	1.20	1.10	0.42
Subordinated Units
Net income (loss) attributable to common and subordinated units per unit (basic)
Per unit (basic) (in usd per share) | $ / shares	0.03	0.05	0.22	0.26	(0.11)	0.14	(0.15)	0.01	0.56	(0.11)	(0.56)
Per unit (diluted) (in usd per share) | $ / shares	0.03	0.05	0.22	0.26	(0.11)	0.14	(0.15)	0.01	0.56	(0.11)	(0.56)
Cash distributions declared and paid per limited partner unit
Per unit (in usd per share) | $ / shares	$ 0.2088	$ 0.2088	$ 0.1838	$ 0.1838	$ 0.1838	$ 0.1838	$ 0.1838	$ 0.1838	$ 0.79	$ 0.74	$ 0.42