Partners' Capital and Distributions (Details 3) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Net Income attributable to Plains
Net income attributable to Plains	$ 231	$ 165	$ 1,052	$ 774
Transfers to the noncontrolling interests:
Increase in capital from sale of PNG units			40
Changes in the noncontrolling interests in partners' capital
Beginning balance			509
Net income attributable to noncontrolling interests	237	173	1,074	797
Equity-indexed compensation expense			31
Distribution equivalent right payments			(4)
Issuance of PNG common units			40
Other comprehensive income/(loss):
Reclassification adjustments			(124)
Net deferred loss on cash flow hedges			140
Ending Balance	534		534
Partners' Capital Excluding Noncontrolling Interests
Net Income attributable to Plains
Net income attributable to Plains	231	165	1,052	774
Transfers to the noncontrolling interests:
Increase in capital from sale of PNG units	2		8
Change from net income attributable to Plains and net transfers to the noncontrolling interest	233	165	1,060	774
Changes in the noncontrolling interests in partners' capital
Net income attributable to noncontrolling interests			1,052
Equity-indexed compensation expense			28
Distribution equivalent right payments			(4)
Issuance of PNG common units	2		8
Noncontrolling Interests
Transfers to the noncontrolling interests:
Increase in capital from sale of PNG units			32
Changes in the noncontrolling interests in partners' capital
Beginning balance			509	524
Net income attributable to noncontrolling interests			22	23
Distribution to noncontrolling interest			(37)	(36)
Equity-indexed compensation expense			3	3
Distribution equivalent right payments				(1)
Issuance of PNG common units			32
Other comprehensive income/(loss):
Reclassification adjustments			6	(7)
Net deferred loss on cash flow hedges			(1)	(1)
Ending Balance	$ 534	$ 505	$ 534	$ 505