Net Income Per Common Unit (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Basic and Diluted Net Income per Common Unit
Net income attributable to PAA	$ 220	$ 203	$ 736	$ 918
Amounts allocated to participating securities	(1)	(1)	(9)	(8)
Other	1	1	3	3
Net income allocated to common unitholders - Basic	157	140	540	728
Net income allocated to common unitholders - Diluted	157	140	540	728
Series A Preferred Units
Basic and Diluted Net Income per Common Unit
Distributions to preferred unitholders	(44)	(44)	(131)	(129)
Series B Preferred Units
Basic and Diluted Net Income per Common Unit
Distributions to preferred unitholders	$ (19)	$ (19)	$ (59)	$ (56)
Common Units
Basic and Diluted Net Income per Common Unit
Basic weighted average common units outstanding (units)	702	700	702	699
Diluted weighted average common units outstanding (units)	702	700	702	699
Basic net income per common unit (usd per unit)	$ 0.22	$ 0.20	$ 0.77	$ 1.04
Diluted net income per common unit (usd per unit)	$ 0.22	$ 0.20	$ 0.77	$ 1.04
Weighted Average | Series A Preferred Units
Net Income/(Loss) Per Common Unit
Antidilutive securities excluded from computation of net income per common unit (units)	71	71	71	71