Equity, Cash Distributions (Details) (USD $)	3 Months Ended			0 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2014 Unit-based compensation awards	Apr. 23, 2014 Subsequent Event
Distribution Made to Member or Limited Partner
Declaration date				Apr. 23, 2014
Cash distributions per unit (dollars per unit)	$ 0.5650	$ 0.4725		$ 0.5900
Distribution date	Feb. 13, 2014			May 15, 2014
Unitholders date of record				May 05, 2014
Total cash distributions declared	$ 38,976,000	$ 23,976,000		$ 39,000,000
Cash distributions paid, per unit (dollars per unit)	$ 0.5650
Total cash distribution paid	$ 36,300,000		$ 300,000