Net Income Per Limited Partner Unit (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	0 Months Ended	3 Months Ended								12 Months Ended
	Oct. 02, 2012	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2012	Dec. 31, 2011	Sep. 30, 2011	Jun. 30, 2011	Mar. 31, 2011	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Basic and Diluted Earnings Per Limited Partner Unit [Line Items]
Unit split conversion ratio	2
General partner ownership interest (as a percent)										2.00%
Numerator for Basic and Diluted Net Income per Limited Partner Unit (prior period adjusted for stock split):
Net income attributable to Plains		$ 320	$ 165	$ 378	$ 230	$ 278	$ 281	$ 225	$ 182	$ 1,094	$ 966	$ 505
Net income available to limited partners										789	730	330
Denominator for Basic and Diluted Net Income per Limited Partner Unit (prior period adjusted for stock split):
Basic weighted average number of limited partner units outstanding (in units)										325	297	274
Effect of dilutive securities (prior period adjusted for stock split):
Weighted average LTIP units (in units)										3	2	1
Diluted weighted average number of limited partner units outstanding (in units)										328	299	275
Basic and Diluted Net Income per Limited Partner Unit
Basic net income per limited partner unit (in dollars per unit)		$ 0.70	$ 0.27	$ 0.93	$ 0.52	$ 0.69	$ 0.74	$ 0.57	$ 0.45	$ 2.41	$ 2.46	$ 1.21
Diluted net income per limited partner unit (in dollars per unit)		$ 0.69	$ 0.27	$ 0.93	$ 0.51	$ 0.68	$ 0.74	$ 0.57	$ 0.45	$ 2.40	$ 2.44	$ 1.20
Basic Net Income Per Limited Partner Unit
Numerator for Basic and Diluted Net Income per Limited Partner Unit (prior period adjusted for stock split):
Net income attributable to Plains										1,094	966	505
Less: General partner's incentive distribution										(289)	(221)	(168)
Less: General partner 2% ownership										(16)	(15)	(7)
Net income available to limited partners										789	730	330
Less: Undistributed earnings allocated and distributions to participating securities										(5)
Net income available to limited partners in accordance with the application of the two-class method for MLPs										784	730	330
Diluted Net Income Per Limited Partner Unit
Numerator for Basic and Diluted Net Income per Limited Partner Unit (prior period adjusted for stock split):
Net income attributable to Plains										1,094	966	505
Less: General partner's incentive distribution										(289)	(221)	(168)
Less: General partner 2% ownership										(16)	(15)	(7)
Net income available to limited partners										789	730	330
Less: Undistributed earnings allocated and distributions to participating securities										(4)
Net income available to limited partners in accordance with the application of the two-class method for MLPs										$ 785	$ 730	$ 330