Net Income per Limited Partner Unit - Net Income Per Unit Table (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Net (Loss) Income per Limited Partner Unit
Net (loss) income attributable to partners	$ (19,335)	$ 1,274
Common Units
Net (Loss) Income per Limited Partner Unit
Distributions declared	9,066	7,999
Earnings less than distributions	(20,380)	(6,905)
Net (loss) income attributable to partners	$ (11,314)	$ 1,094
Weighted-average units outstanding - basic	14,438	14,380
Weighted-average units outstanding - diluted	14,438	15,228
Net (loss) income per limited partner unit - basic	$ (0.78)	$ 0.08
Net (loss) income per limited partner unit - diluted	$ (0.78)	$ 0.07
Subordinated Units-Sponsor
Net (Loss) Income per Limited Partner Unit
Distributions declared	$ 7,441	$ 6,607
Earnings less than distributions	(16,726)	(5,703)
Net (loss) income attributable to partners	$ (9,285)	$ 904
Weighted-average units outstanding - basic	11,905	11,905
Weighted-average units outstanding - diluted	11,905	11,905
Net (loss) income per limited partner unit - basic	$ (0.78)	$ 0.08
Net (loss) income per limited partner unit - diluted	$ (0.78)	$ 0.08
General Partner
Net (Loss) Income per Limited Partner Unit
Distributions declared	$ 1,264	$ 537
Net (loss) income attributable to partners	1,264	537
Limited Partners
Net (Loss) Income per Limited Partner Unit
Distributions declared	17,771	15,143
Earnings less than distributions	(37,106)	(12,608)
Net (loss) income attributable to partners	$ (19,335)	$ 2,535