Earnings Per Share (Tables)

12 Months Ended

Dec. 31, 2019

Earnings Per Share [Abstract]

Reconciliation of Basic and Diluted Earnings Per Share

	2019					2018			2017
	Basic			Diluted		Basic		Diluted	Basic		Diluted
Amounts Attributed to Phillips 66 Common Stockholders (millions):
Net income attributable to Phillips 66	$	3,076		3,076		5,595		5,595	5,106		5,106
Income allocated to participating securities	(6		)	(2	)	(6	)	—	(6	)	—
Net income available to common stockholders	$	3,070		3,074		5,589		5,595	5,100		5,106
Weighted-average common shares outstanding (thousands):	448,787			451,364		467,483		470,708	511,268		515,090
Effect of share-based compensation	2,577			2,524		3,225		3,339	3,822		3,418
Weighted-average common shares outstanding—EPS	451,364			453,888		470,708		474,047	515,090		518,508
Earnings Per Share of Common Stock (dollars)	$	6.80		6.77		11.87		11.80	9.90		9.85