Partners' Capital and Distributions - Noncontrolling Interests in Subsidiaries (Details) $ in Millions	3 Months Ended
	Mar. 31, 2020 USD ($)
Partners' Capital and Distributions
Contribution from noncontrolling interests	$ 8
Noncontrolling Interests
Partners' Capital and Distributions
Contribution from noncontrolling interests	$ 8
AAP
Partners' Capital and Distributions
Noncontrolling interests in subsidiaries (percent)	25.00%
Red River LLC
Partners' Capital and Distributions
Noncontrolling interests in subsidiaries (percent)	33.00%
Common Units and Series A Preferred Units | PAA
Partners' Capital and Distributions
Noncontrolling interests in subsidiaries (percent)	69.00%
Series B Preferred Units | PAA
Partners' Capital and Distributions
Noncontrolling interests in subsidiaries (percent)	100.00%
Red River LLC | Noncontrolling Interests
Partners' Capital and Distributions
Contribution from noncontrolling interests	$ 8