Consolidated Statement of Comprehensive Income - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement of Comprehensive Income [Abstract]
Net Income	$ 1,504	$ 1,404	$ 1,774	$ 1,989
Defined benefit plans
Amortization to income of net actuarial loss, prior service credit and settlements	15	21	34	43
Plans sponsored by equity affiliates	1	3	5	9
Income taxes on defined benefit plans	(4)	(5)	(9)	(12)
Defined benefit plans, net of income taxes	12	19	30	40
Foreign currency translation adjustments	(62)	(201)	(5)	(110)
Income taxes on foreign currency translation adjustments	(1)	4	(1)	1
Foreign currency translation adjustments, net of income taxes	(63)	(197)	(6)	(109)
Cash flow hedges	(7)	2	(11)	8
Income taxes on hedging activities	0	0	1	(2)
Hedging activities, net of income taxes	(7)	2	(10)	6
Other Comprehensive Income (Loss), Net of Income Taxes	(58)	(176)	14	(63)
Comprehensive Income	1,446	1,228	1,788	1,926
Less: comprehensive income attributable to noncontrolling interests	80	65	146	126
Comprehensive Income Attributable to Phillips 66	$ 1,366	$ 1,163	$ 1,642	$ 1,800