Net Income Per Limited Partner Unit - Reconciliation of Net Income (Loss) and Weighted-Average Units Used in Computing Basic and Diluted Net Income (Loss) Per Limited Partner Unit (Details) - USD ($) $ / shares in Units, $ in Thousands		3 Months Ended
		Mar. 31, 2019	Mar. 31, 2018
Numerator:
Distributions paid		$ 18,099	$ 21,415
Allocation of distributions in excess of net income (loss)		(18,020)	(23,400)
Limited partners’ interest in net income (loss) - basic and diluted		$ 79	$ (1,985)
Denominator:
Weighted-average limited partnership units outstanding - basic		34,444,113	34,157,088
Adjustment for phantom and phantom performance units	[1]	12,352
Weighted-average limited partnership units outstanding - diluted		34,456,465	34,157,088
Net income (loss) per limited partnership unit - basic and diluted		$ 0.00	$ (0.06)
Distributions paid per common unit		0.5250	0.6275
Distributions declared (with respect to each respective period) per common unit		$ 0.5250	$ 0.5250

[1] Excludes 7,971 potentially dilutive securities from the calculation of diluted earnings per common unit because to do so would be antidilutive for the three months ended March 31, 2018.