Consolidated balance sheets (Parenthetical)	3 Months Ended	12 Months Ended
	Mar. 31, 2014	Dec. 31, 2013
Consolidated balance sheets
Common unitholders, units issued	16,124,566	16,124,566
Common unitholders, units outstanding	16,124,566	16,124,566
General partner interest (as a percent)	2.00%	2.00%
General partner interest, equivalent units outstanding	329,073	329,073