Members' Equity/Partners' Capital (EPU) (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Weighted Common Units - Basic and Diluted (in units)	14,039,726	4,658,970
Restricted unvested common units granted and outstanding	283,138	219,144	361,357
Assumed net loss to be allocated	$ (40,711)	$ (44,484)
Asset impairments	$ 4,688	$ 7,646
Common units
Weighted Common Units - Basic and Diluted (in units)	14,039,726	4,658,970
Assumed net loss to be allocated	$ (40,711)	$ (44,484)
Basic and diluted loss per unit (in dollars per share)	$ (2.90)	$ (9.55)
Common units | Prior To Stock Split
Weighted Common Units - Basic and Diluted (in units)	14,039,726	4,658,970
Restricted Unvested Units
Assumed net loss to be allocated	$ 0	$ 0