Consolidated Statement of Comprehensive Income (Loss) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Statement of Comprehensive Income [Abstract]
Net Income (Loss)	$ 657	$ (639)
Defined benefit plans
Amortization of net actuarial loss, prior service credit and settlements	11	22
Plans sponsored by equity affiliates	5	6
Income taxes on defined benefit plans	(3)	(6)
Defined benefit plans, net of income taxes	13	22
Foreign currency translation adjustments	(82)	(15)
Income taxes on foreign currency translation adjustments	0	0
Foreign currency translation adjustments, net of income taxes	(82)	(15)
Cash flow hedges	0	2
Income taxes on hedging activities	0	0
Hedging activities, net of income taxes	0	2
Other Comprehensive Income (Loss), Net of Income Taxes	(69)	9
Comprehensive Income (Loss)	588	(630)
Less: comprehensive income attributable to noncontrolling interests	75	15
Comprehensive Income (Loss) Attributable to Phillips 66	$ 513	$ (645)