Selected Quarterly Financial Information—Unaudited (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Interim Reporting [Line Items]
Total revenue	$ 103,028	$ 137,369	$ 163,618	$ 83,806	$ 246,047	$ 139,718	$ 109,309	$ 114,494	$ 487,821	$ 609,568	$ 429,659
Income (loss) from operations	44,679	75,233	100,666	14,594	170,717	66,180	33,524	47,960	235,172	318,381	172,084
Net income (loss)	40,017	70,247	95,087	9,017	164,138	60,775	28,690	41,957	214,368	295,560	157,153
Net income (loss) attributable to the general partner and common and subordinated units	34,767	64,997	89,837	3,767	158,865	55,503	23,488	36,655	193,368	274,511	$ 152,145
Cash distributions declared and paid per limited partner unit
Total assets	1,545,208	1,595,813	1,724,555	1,711,887	1,750,124	1,754,259	1,669,464	1,635,978	1,545,208	1,750,124
Long-term debt	394,000	413,000	436,000	435,000	410,000	402,000	421,000	436,000	394,000	410,000
Total mezzanine equity	$ 298,361	$ 298,361	$ 298,361	$ 298,361	$ 298,361	$ 298,361	$ 298,361	$ 300,644	$ 298,361	$ 298,361
Common Units
Net income (loss) attributable to common and subordinated units per unit (basic)
Per unit (basic) (in usd per share)	$ 170	$ 320	$ 450	$ 20.00	$ 0.78	$ 0.27	$ 0.17	$ 0.23	$ 1.01	$ 1.46	$ 1.01
Per unit (diluted) (in usd per share)	170	320	440	20.00	0.72	0.27	0.17	0.23	1.01	1.45	1.01
Cash distributions declared and paid per limited partner unit
Per unit (in usd per share)	0.3700	0.3700	0.3700	0.3700	0.3700	0.3375	0.3125	0.3125	1.48	1.33	1.20
Subordinated Units
Net income (loss) attributable to common and subordinated units per unit (basic)
Per unit (basic) (in usd per share)	0	0	390	20.00	0.78	0.27	0.06	0.13	0.64	1.25	0.56
Per unit (diluted) (in usd per share)	0	0	390	20.00	0.78	0.27	0.06	0.13	0.64	1.25	0.56
Cash distributions declared and paid per limited partner unit
Per unit (in usd per share)	$ 0	$ 0	$ 0.3700	$ 0.3700	$ 0.3700	$ 0.3375	$ 0.2087	$ 0.2088	$ 0.74	$ 1.13	$ 0.79