Segment Information - Segment Adjusted EBITDA Reconciliation (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024
Segment Reporting Information
Unallocated general and administrative expenses	$ (101)	$ (97)
Depreciation and amortization	(262)	(254)
Gain on asset sales, net	13
Gain on investments in unconsolidated entities, net	31
Interest expense, net	(107)	(95)
Other income/(expense), net	6	(5)
INCOME BEFORE TAX	565	364
Net income	492	336
Net income attributable to noncontrolling interests	(408)	(294)
Net income attributable to PAGP	84	42
Segment Reporting, Reconciling Item, Corporate Nonsegment
Segment Reporting Information
Segment Adjusted EBITDA	748	712
Total other segment items	137	7
Unallocated general and administrative expenses	(1)	(1)
Depreciation and amortization	(262)	(254)
Gain on asset sales, net	13
Gain on investments in unconsolidated entities, net	31	0
Interest expense, net	(107)	(95)
Other income/(expense), net		(5)
INCOME BEFORE TAX	565	364
Income tax expense	(73)	(28)
Net income	492	336
Net income attributable to noncontrolling interests	(408)	(294)
Net income attributable to PAGP	$ 84	$ 42