Equity, Cash Distributions (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended				6 Months Ended		0 Months Ended
	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013	Jul. 24, 2014 Subsequent Event
Distribution Made to Member or Limited Partner
Quarterly Distribution Per Unit (dollars per unit)		$ 0.590	$ 0.565				$ 0.615	[1]
Total Cash Distribution including general partner IDRs (in thousands)	$ 42,132	$ 38,976	$ 36,265	$ 26,108	$ 81,108	$ 50,084	$ 42,132	[1]
Date of Distribution		May 15, 2014	Feb. 13, 2014				Aug. 14, 2014	[1]
Unitholders Record Date		May 05, 2014	Feb. 03, 2014				Aug. 04, 2014	[1]
Declaration date							Jul. 24, 2014

[1] This distribution was declared on July 24, 2014 and will be paid on the date of distribution.