CONDENSED CONSOLIDATED STATEMENTS OF COMPREHENSIVE INCOME/(LOSS) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Statement of Comprehensive Income [Abstract]
Net income/(loss)	$ (2,692)	$ 914
Other comprehensive income/(loss)	(327)	58
Comprehensive income/(loss)	(3,019)	972
Comprehensive (income)/loss attributable to noncontrolling interests	2,356	(812)
Comprehensive income/(loss) attributable to PAGP	$ (663)	$ 160