Consolidated statements of partners' equity (Parenthetical) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2014	Dec. 31, 2013
Consolidated statements of partners' equity
Public offering of common units (in units)		1,667,500
Proceeds from offering, underwriters' discounts and offering expenses (in dollars)		$ 3,462
General partner interest (as a percent)	2.00%	2.00%
Purchase of common units by our long-term incentive plan and from affiliate	2,001	13,069
Issuance of common units by our long-term incentive plan due to vesting of restricted phantom units	5,500	10,608