Condensed Consolidating Financial Information (Income Statement) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2014		Dec. 31, 2013		Dec. 31, 2012
Revenues and Other Income
Sales and other operating revenues	$ 161,212	[1],[2]	$ 171,596	[1],[2]	$ 179,290	[1],[2]
Equity in earnings of affiliates	2,466		3,073		3,134
Net gain on dispositions	295		55		193
Other income (loss)	120		85		135
Total Revenues and Other Income	164,093		174,809		182,752
Costs and Expenses
Purchased crude oil and products	135,748		148,245		154,413
Operating expenses	4,435		4,206		4,033
Selling, general and administrative expenses	1,663		1,478		1,703
Depreciation and amortization	995		947		906
Impairments	150		29		1,158
Taxes other than income taxes	15,040	[2]	14,119	[2]	13,740	[2]
Accretion on discounted liabilities	24		24		25
Interest and debt expense	267		275		246
Foreign currency transaction (gains) losses	26		(40)		(28)
Total Costs and Expenses	158,348		169,283		176,196
Income from continuing operations before income taxes	5,745		5,526		6,556
Provision (benefit) for income taxes	1,654		1,844		2,473
Income from Continuing Operations	4,091		3,682		4,083
Income from discontinued operations	706	[3],[4]	61	[3],[5]	48	[3],[6]
Net income	4,797		3,743		4,131
Less: net income attributable to noncontrolling interests	35		17		7
Net Income Attributable to Phillips 66	4,762		3,726		4,124
Comprehensive Income	4,229		4,094		4,235
Phillips 66 [Member]
Revenues and Other Income
Equity in earnings of affiliates	4,257		3,905		4,284
Other income (loss)			(3)		2
Total Revenues and Other Income	4,257		3,902		4,287
Costs and Expenses
Operating expenses	2
Selling, general and administrative expenses	6		6		4
Interest and debt expense	286		266		212
Total Costs and Expenses	294		272		216
Income from continuing operations before income taxes	3,963		3,630		4,071
Provision (benefit) for income taxes	(103)		(96)		(53)
Income from Continuing Operations	4,066		3,726		4,124
Income from discontinued operations	696	[4]
Net income	4,762		3,726		4,124
Net Income Attributable to Phillips 66	4,762		3,726		4,124
Comprehensive Income	4,194		4,077		4,228
Phillips 66 Company [Member]
Revenues and Other Income
Equity in earnings of affiliates	3,021		3,363		3,064
Net gain on dispositions	(46)		49		192
Other income (loss)	105		53		(15)
Total Revenues and Other Income	114,569		118,760		123,766
Costs and Expenses
Purchased crude oil and products	97,783		102,780		106,687
Operating expenses	3,600		3,442		3,329
Selling, general and administrative expenses	1,224		1,025		1,319
Depreciation and amortization	761		730		668
Impairments	3				71
Taxes other than income taxes	5,478		5,147		5,155
Accretion on discounted liabilities	18		19		18
Interest and debt expense	18		13		29
Total Costs and Expenses	108,885		113,156		117,276
Income from continuing operations before income taxes	5,684		5,604		6,490
Provision (benefit) for income taxes	1,427		1,699		2,206
Income from Continuing Operations	4,257		3,905		4,284
Net income	4,257		3,905		4,284
Net Income Attributable to Phillips 66	4,257		3,905		4,284
Comprehensive Income	3,689		4,256		4,388
All Other Subsidiaries [Member]
Revenues and Other Income
Equity in earnings of affiliates	444		509		445
Net gain on dispositions	341		6		1
Other income (loss)	15		35		148
Total Revenues and Other Income	71,706		78,270		85,444
Costs and Expenses
Purchased crude oil and products	58,984		66,746		73,715
Operating expenses	870		790		760
Selling, general and administrative expenses	502		540		421
Depreciation and amortization	234		217		238
Impairments	147		29		1,087
Taxes other than income taxes	9,563		8,973		8,586
Accretion on discounted liabilities	6		5		7
Interest and debt expense	20		14		4
Foreign currency transaction (gains) losses	26		(40)		(28)
Total Costs and Expenses	70,352		77,274		84,790
Income from continuing operations before income taxes	1,354		996		654
Provision (benefit) for income taxes	330		241		320
Income from Continuing Operations	1,024		755		334
Income from discontinued operations	10	[4]	61	[5]	48	[6]
Net income	1,034		816		382
Less: net income attributable to noncontrolling interests	35		17		7
Net Income Attributable to Phillips 66	999		799		375
Comprehensive Income	721		839		418
Reportable Legal Entities [Member] | Phillips 66 Company [Member]
Revenues and Other Income
Sales and other operating revenues	109,078		113,499		117,574
Reportable Legal Entities [Member] | All Other Subsidiaries [Member]
Revenues and Other Income
Sales and other operating revenues	52,134		58,097		61,716
Consolidating Adjustments [Member]
Revenues and Other Income
Sales and other operating revenues	(21,183)		(21,419)		(26,086)
Equity in earnings of affiliates	(5,256)		(4,704)		(4,659)
Total Revenues and Other Income	(26,439)		(26,123)		(30,745)
Costs and Expenses
Purchased crude oil and products	(21,019)		(21,281)		(25,989)
Operating expenses	(37)		(26)		(56)
Selling, general and administrative expenses	(69)		(93)		(41)
Taxes other than income taxes	(1)		(1)		(1)
Interest and debt expense	(57)		(18)		1
Total Costs and Expenses	(21,183)		(21,419)		(26,086)
Income from continuing operations before income taxes	(5,256)		(4,704)		(4,659)
Income from Continuing Operations	(5,256)		(4,704)		(4,659)
Net income	(5,256)		(4,704)		(4,659)
Net Income Attributable to Phillips 66	(5,256)		(4,704)		(4,659)
Comprehensive Income	(4,375)		(5,078)		(4,799)
Consolidating Adjustments [Member] | Phillips 66 [Member]
Revenues and Other Income
Sales and other operating revenues					(1)
Consolidating Adjustments [Member] | Phillips 66 Company [Member]
Revenues and Other Income
Sales and other operating revenues	(2,411)		(1,796)		(2,951)
Consolidating Adjustments [Member] | All Other Subsidiaries [Member]
Revenues and Other Income
Sales and other operating revenues	$ (18,772)		$ (19,623)		$ (23,134)

[1] Sales and other operating revenues are attributable to countries based on the location of the operations generating the revenues.

[2] Includes excise taxes on petroleum products sales: $14,698 million, $13,866 million, $13,371 million

[3] Net of provision for income taxes on discontinued operations: $5 million, $34 million, $27 million

[4] Net of provision for income taxes on discontinued operations: $-, $-, $5, $-, $5

[5] Net of provision for income taxes on discontinued operations: $-, $-, $34, $-, $34

[6] Net of provision for income taxes on discontinued operations: $-, $-, $27, $-, $27