Partners' Capital and Distributions (Details) (Class A Shares, USD $) In Millions, except Per Share data, unless otherwise specified	0 Months Ended	6 Months Ended	0 Months Ended	6 Months Ended	0 Months Ended	6 Months Ended
Aug. 14, 2014 Second Quarter Distribution Subsequent Event	Jun. 30, 2014 Second Quarter Distribution Subsequent Event	May 15, 2014 First Quarter Distribution	Jun. 30, 2014 First Quarter Distribution	Feb. 14, 2014 Fourth quarter distribution	Jun. 30, 2014 Fourth quarter distribution
Partners Capital and Distribution
Date Declared		Jul. 08, 2014		Apr. 07, 2014		Jan. 09, 2014
Distribution Date		Aug. 14, 2014		May 15, 2014		Feb. 14, 2014
Distributions to Class A shareholders	$ 25		$ 23		$ 17
Distribution per Class A share (in dollars per share)	$ 0.18340		$ 0.17055		$ 0.12505
Shareholders of record, date		Aug. 01, 2014

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Date of record for distribution of cash or unit to limited partner of limited partnership (LP), in CCYY-MM-DD format.

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Date of declaration for distribution of cash or unit to limited partner of limited partnership (LP), in CCYY-MM-DD format.

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Per unit of ownership amount of cash distributions paid to unit-holder of a limited partnership (LP).

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