Operating Segments (Details 2) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Reconciliation of segment profit to net income attributable to Plains
Segment profit	$ 513	$ 609
Unallocated general and administrative expenses	(1)	(1)
Depreciation and amortization	(108)	(96)
Interest expense, net	(104)	(81)
Other expense, net	(4)	(2)
INCOME BEFORE TAX	296	429
Income tax expense	(34)	(57)
NET INCOME	262	372
Net income attributable to noncontrolling interests	(231)	(358)
NET INCOME ATTRIBUTABLE TO PAGP	$ 31	$ 14