CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME/(LOSS) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Statement of Comprehensive Income [Abstract]
Net income/(loss)	$ 239	$ (212)	$ 448	$ 181
Other comprehensive income/(loss)	(52)		22	108
Comprehensive income/(loss)	187	(212)	470	289
Comprehensive (income)/loss attributable to noncontrolling interests	(170)	143	(411)	(259)
Comprehensive income/(loss) attributable to PAGP	$ 17	$ (69)	$ 59	$ 30