Partners' Capital and Distributions (Details) - USD ($) $ / shares in Units, $ in Millions					9 Months Ended
	Nov. 13, 2015	Aug. 14, 2015	May. 15, 2015	Feb. 13, 2015	Sep. 30, 2015	Sep. 30, 2014
Partners Capital and Distribution
Percentage of distribution amount to the general partner before incentive distributions					2.00%
Total distributions paid during the period					$ 1,240	$ 1,034
Second Quarter Distribution
Partners Capital and Distribution
Distributions paid to Limited Partners		$ 276
Distributions paid to General Partner - 2%		6
Distributions paid to General Partner - Incentive		146
Total distributions paid during the period		$ 428
Distributions per limited partner unit		$ 0.6950
Distribution declared, date					Jul. 07, 2015
Distribution Date					Aug. 14, 2015
First Quarter Distribution
Partners Capital and Distribution
Distributions paid to Limited Partners			$ 272
Distributions paid to General Partner - 2%			6
Distributions paid to General Partner - Incentive			142
Total distributions paid during the period			$ 420
Distributions per limited partner unit			$ 0.6850
Distribution declared, date					Apr. 07, 2015
Distribution Date					May 15, 2015
Fourth Quarter Distribution
Partners Capital and Distribution
Distributions paid to Limited Partners				$ 254
Distributions paid to General Partner - 2%				5
Distributions paid to General Partner - Incentive				131
Total distributions paid during the period				$ 390
Distributions per limited partner unit				$ 0.6750
Distribution declared, date					Jan. 08, 2015
Distribution Date					Feb. 13, 2015
Subsequent Event | Third Quarter Distribution
Partners Capital and Distribution
Distributions paid to Limited Partners	$ 279
Distributions paid to General Partner - 2%	6
Distributions paid to General Partner - Incentive	148
Total distributions paid during the period	$ 433
Distributions per limited partner unit	$ 0.7000
Distribution declared, date					Oct. 07, 2015
Distribution Date					Nov. 13, 2015
Unitholders of record, date					Oct. 30, 2015