Subsequent Events (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended	6 Months Ended	1 Months Ended	3 Months Ended	6 Months Ended		1 Months Ended
	Mar. 31, 2013	Jun. 30, 2013	Jul. 31, 2013 Subsequent Event [Member]	Sep. 30, 2013 Subsequent Event [Member]	Jun. 30, 2013 Subsequent Event [Member]	Jul. 24, 2013 Subsequent Event [Member]	Aug. 31, 2013 2013 East Texas Acquisition [Member] Subsequent Event [Member]
Subsequent Event [Line Items]
Date of acquisition							Aug. 06, 2013
Cash paid for acquisition							$ 109
Date distribution was declared			Jul. 24, 2013		Jul. 24, 2013
Cash distribution per unit						$ 0.4875
Date distribution will be paid			Aug. 14, 2013		Aug. 14, 2013
Date unitholders of record			Aug. 07, 2013		Aug. 07, 2013
Management incentive fee incurred	$ 0.7	$ 0.7		$ 1.3