Phillips 66 (PSX) 10-K 23 Feb 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Billions	12 Months Ended
	Dec. 31, 2017	Jan. 31, 2018	Jun. 30, 2017
Document and Entity Information [Abstract]
Trading Symbol	PSX
Entity Registrant Name	Phillips 66
Entity Central Index Key	1,534,701
Document Type	10-K
Document Period End Date	Dec. 31, 2017
Amendment Flag	false
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		501,237,339
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 42.3

Consolidated Statement of Incom

Consolidated Statement of Income - USD ($) shares in Thousands, $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenues and Other Income
Sales and other operating revenues	[1]	$ 102,354	$ 84,279	$ 98,975
Equity in earnings of affiliates		1,732	1,414	1,573
Net gain on dispositions		15	10	283
Other income		521	74	118
Total Revenues and Other Income		104,622	85,777	100,949
Costs and Expenses
Purchased crude oil and products		79,409	62,468	73,399
Operating expenses		4,699	4,275	4,294
Selling, general and administrative expenses		1,695	1,638	1,670
Depreciation and amortization		1,318	1,168	1,078
Impairments		24	5	7
Taxes other than income taxes	[1]	13,462	13,688	14,077
Accretion on discounted liabilities		22	21	21
Interest and debt expense		438	338	310
Foreign currency transaction (gains) losses		0	(15)	49
Total Costs and Expenses		101,067	83,586	94,905
Income before income taxes		3,555	2,191	6,044
Income tax expense (benefit)		(1,693)	547	1,764
Net Income		5,248	1,644	4,280
Less: net income attributable to noncontrolling interests		142	89	53
Net Income Attributable to Phillips 66		$ 5,106	$ 1,555	$ 4,227
Net Income Attributable to Phillips 66 Per Share of Common Stock (dollars)
Basic (in dollars per share)		$ 9.90	$ 2.94	$ 7.78
Diluted (in dollars per share)		9.85	2.92	7.73
Dividends Paid Per Share of Common Stock (in dollars per share)		$ 2.73	$ 2.4500	$ 2.18
Weighted-Average Common Shares Outstanding
Basic (in shares)		515,090	527,531	542,355
Diluted (in shares)		518,508	530,066	546,977
[1]	Includes excise taxes on petroleum products sales: $13,054 million, $13,381 million, $13,780 million

Consolidated Statement of Inco3

Consolidated Statement of Income (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement [Abstract]
Includes excise taxes on sales of petroleum products	$ 13,054	$ 13,381	$ 13,780

Consolidated Statement of Compr

Consolidated Statement of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Net Income	$ 5,248	$ 1,644	$ 4,280
Defined benefit plans
Actuarial loss arising during the period	(1)	(178)	(138)
Amortization to net income of net actuarial loss and settlements	176	94	174
Curtailment gain	0	31	0
Plans sponsored by equity affiliates	10	(11)	11
Income taxes on defined benefit plans	(70)	13	(13)
Defined benefit plans, net of tax	115	(51)	34
Foreign currency translation adjustments	268	(301)	(163)
Income taxes on foreign currency translation adjustments	(9)	5	7
Foreign currency translation adjustments, net of tax	259	(296)	(156)
Cash flow hedges	6	8	0
Income taxes on hedging activities	(2)	(3)	0
Hedging activities, net of tax	4	5	0
Other Comprehensive Income (Loss), Net of Tax	378	(342)	(122)
Comprehensive Income	5,626	1,302	4,158
Less: comprehensive income attributable to noncontrolling interests	142	89	53
Comprehensive Income Attributable to Phillips 66	$ 5,484	$ 1,213	$ 4,105

Consolidated Balance Sheet

Consolidated Balance Sheet - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Assets
Cash and cash equivalents	$ 3,119	$ 2,711
Accounts and notes receivable (net of allowances of $29 million in 2017 and $34 million in 2016)	6,424	5,485
Accounts and notes receivable—related parties	1,082	912
Inventories	3,395	3,150
Prepaid expenses and other current assets	370	422
Total Current Assets	14,390	12,680
Investments and long-term receivables	13,941	13,534
Net properties, plants and equipment	21,460	20,855
Goodwill	3,270	3,270
Intangibles	876	888
Other assets	434	426
Total Assets	54,371	51,653
Liabilities
Accounts payable	7,242	6,395
Accounts payable—related parties	785	666
Short-term debt	41	550
Accrued income and other taxes	1,002	805
Employee benefit obligations	582	527
Other accruals	455	520
Total Current Liabilities	10,107	9,463
Long-term debt	10,069	9,588
Asset retirement obligations and accrued environmental costs	641	655
Deferred income taxes	5,008	6,743
Employee benefit obligations	884	1,216
Other liabilities and deferred credits	234	263
Total Liabilities	26,943	27,928
Equity
Common stock (2,500,000,000 shares authorized at $.01 par value) Issued (2017—643,835,464 shares; 2016—641,593,854 shares)	6	6
Capital in excess of par	19,768	19,559
Treasury stock (at cost: 2017—141,565,145 shares; 2016—122,827,264 shares)	(10,378)	(8,788)
Retained earnings	16,306	12,608
Accumulated other comprehensive loss	(617)	(995)
Total Stockholders’ Equity	25,085	22,390
Noncontrolling interests	2,343	1,335
Total Equity	27,428	23,725
Total Liabilities and Equity	$ 54,371	$ 51,653

Consolidated Balance Sheet (Par

Consolidated Balance Sheet (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Allowance for accounts and notes receivable	$ 29	$ 34
Common Stock, shares authorized (in shares)	2,500,000,000	2,500,000,000
Common Stock, Par Value (in usd per share)	$ 0.01	$ 0.01
Common Stock, shares issued (in shares)	643,835,000	641,594,000
Treasury Stock Repurchase Plan
Treasury Stock, shares repurchased (in shares)	141,565,000	122,827,000

Consolidated Statement of Cash

Consolidated Statement of Cash Flows - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash Flows From Operating Activities
Net Income		$ 5,248	$ 1,644	$ 4,280
Adjustments to reconcile net income to net cash provided by operating activities
Depreciation and amortization		1,318	1,168	1,078
Impairments		24	5	7
Accretion on discounted liabilities		22	21	21
Deferred income taxes		(1,886)	612	529
Undistributed equity earnings		(516)	(815)	185
Net gain on dispositions		(15)	(10)	(283)
Gain on consolidation of business		(423)	0	0
Other		(186)	(163)	117
Working capital adjustments
Decrease (increase) in accounts and notes receivable		(1,182)	(1,258)	2,129
Decrease (increase) in inventories		(176)	216	(144)
Decrease (increase) in prepaid expenses and other current assets		104	(147)	324
Increase (decrease) in accounts payable		1,153	1,579	(2,300)
Increase (decrease) in taxes and other accruals		163	111	(230)
Net Cash Provided by Operating Activities		3,648	2,963	5,713
Cash Flows From Investing Activities
Capital expenditures and investments		(1,832)	(2,844)	(5,764)
Proceeds from asset dispositions	[1]	86	156	70
Advances/loans—related parties		(10)	(432)	(50)
Collection of advances/loans—related parties		326	108	50
Restricted cash received from consolidation of business		318	0	0
Other		(34)	(146)	(44)
Net Cash Used in Investing Activities		(1,146)	(3,158)	(5,738)
Cash Flows From Financing Activities
Issuance of debt		3,508	2,090	1,169
Repayment of debt		(3,678)	(833)	(926)
Issuance of common stock		35	34	31
Repurchase of common stock		(1,590)	(1,042)	(1,512)
Dividends paid on common stock		(1,395)	(1,282)	(1,172)
Distributions to noncontrolling interests		(120)	(75)	(46)
Net proceeds from issuance of Phillips 66 Partners LP common and preferred units		1,205	972	384
Other		(76)	(42)	(45)
Net Cash Used in Financing Activities		(2,111)	(178)	(2,117)
Effect of Exchange Rate Changes on Cash, Cash Equivalents and Restricted Cash		17	10	9
Net Change in Cash, Cash Equivalents and Restricted Cash		408	(363)	(2,133)
Cash, cash equivalents and restricted cash at beginning of period		2,711	3,074	5,207
Cash, Cash Equivalents and Restricted Cash at End of Period		$ 3,119	$ 2,711	$ 3,074
[1]	Includes return of investments in equity affiliates.

Consolidated Statement of Chang

Consolidated Statement of Changes in Equity - USD ($) shares in Thousands, $ in Millions	Total	Common Stock	Capital in Excess of Par	Treasury Stock	Treasury Stock Repurchase Plan	Retained Earnings	Accum. Other Comprehensive Loss	Noncontrolling Interests
Beginning Balance at Dec. 31, 2014	$ 22,037	$ 6	$ 19,040	$ (6,234)		$ 9,309	$ (531)	$ 447
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	4,280					4,227		53
Other comprehensive income (loss)	(122)						(122)
Cash dividends paid on common stock	(1,172)					(1,172)
Repurchase of common stock	(1,512)			(1,512)
Benefit plan activity	89		105			(16)
Issuance of Phillips 66 Partners LP common and preferred units	384							384
Distributions to noncontrolling interests	(46)							(46)
Ending Balance at Dec. 31, 2015	$ 23,938	6	19,145	(7,746)		12,348	(653)	838
Beginning Balance, Common shares (in shares) at Dec. 31, 2014	637,032
Beginning Balance, Treasury shares (in shares) at Dec. 31, 2014					90,650
Shares
Shares issued—share-based compensation (in shares)	2,304
Repurchase of common stock (in shares)					19,276
Ending Balance, Common shares (in shares) at Dec. 31, 2015	639,336
Ending Balance, Treasury shares (in shares) at Dec. 31, 2015					109,926
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	$ 1,644					1,555		89
Other comprehensive income (loss)	(342)						(342)
Cash dividends paid on common stock	(1,282)					(1,282)
Repurchase of common stock	(1,042)			(1,042)
Benefit plan activity	93		106			(13)
Issuance of Phillips 66 Partners LP common and preferred units	791		308					483
Distributions to noncontrolling interests	(75)							(75)
Ending Balance at Dec. 31, 2016	$ 23,725	6	19,559	(8,788)		12,608	(995)	1,335
Shares
Shares issued—share-based compensation (in shares)	2,258
Repurchase of common stock (in shares)					12,901
Ending Balance, Common shares (in shares) at Dec. 31, 2016	641,594
Ending Balance, Treasury shares (in shares) at Dec. 31, 2016					122,827
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income	$ 5,248					5,106		142
Other comprehensive income (loss)	378						378
Cash dividends paid on common stock	(1,395)					(1,395)
Repurchase of common stock	(1,590)			(1,590)
Benefit plan activity	59		72			(13)
Issuance of Phillips 66 Partners LP common and preferred units	1,123		137					986
Distributions to noncontrolling interests	(120)							(120)
Ending Balance at Dec. 31, 2017	$ 27,428	$ 6	$ 19,768	$ (10,378)		$ 16,306	$ (617)	$ 2,343
Shares
Shares issued—share-based compensation (in shares)	2,241
Repurchase of common stock (in shares)					18,738
Ending Balance, Common shares (in shares) at Dec. 31, 2017	643,835
Ending Balance, Treasury shares (in shares) at Dec. 31, 2017					141,565

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Policies	Summary of Significant Accounting Policies ▪ Consolidation Principles and Investments —Our consolidated financial statements include the accounts of majority-owned, controlled subsidiaries and variable interest entities where we are the primary beneficiary. The equity method is used to account for investments in affiliates in which we have the ability to exert significant influence over the affiliates’ operating and financial policies. When we do not have the ability to exert significant influence, the investment is classified either as available-for-sale if fair value is readily determinable, or as the cost method if fair value is not readily determinable. Undivided interests in pipelines, natural gas plants and terminals are consolidated on a proportionate basis. Other securities and investments are generally carried at cost. ▪ Recasted Financial Information —Certain prior period financial information has been recasted to reflect the current year’s presentation. ▪ Foreign Currency Translation —Adjustments resulting from the process of translating foreign functional currency financial statements into U.S. dollars are included in accumulated other comprehensive income (loss) in stockholders’ equity. Foreign currency transaction gains and losses result from remeasuring monetary assets and liabilities denominated in a foreign currency into the functional currency of our subsidiary holding the asset or liability. We include these transaction gains and losses in current earnings. Most of our foreign operations use their local currency as the functional currency. ▪ Use of Estimates —The preparation of financial statements in conformity with generally accepted accounting principles in the United States requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses, and the disclosures of contingent assets and liabilities. Actual results could differ from these estimates. ▪ Revenue Recognition —Revenues associated with sales of crude oil, natural gas liquids (NGL), petroleum and chemical products, and other items are recognized when title passes to the customer, which is when the risk of ownership passes to the purchaser and physical delivery of goods occurs, either immediately or within a fixed delivery schedule that is reasonable and customary in the industry. Revenues associated with transactions commonly called buy/sell contracts, in which the purchase and sale of inventory with the same counterparty are entered into in contemplation of one another, are combined and reported in the “Purchased crude oil and products” line on our consolidated statement of income (i.e., these transactions are recorded net). ▪ Cash Equivalents —Cash equivalents are highly liquid, short-term investments that are readily convertible to known amounts of cash and will mature within 90 days or less from the date of acquisition. We carry these investments at cost plus accrued interest. ▪ Shipping and Handling Costs —We record shipping and handling costs in the “Purchased crude oil and products” line on our consolidated statement of income. Freight costs billed to customers are recorded in “Sales and other operating revenues.” ▪ Inventories —We have several valuation methods for our various types of inventories and consistently use the following methods for each type of inventory. Crude oil and petroleum products inventories are valued at the lower of cost or market in the aggregate, primarily on the last-in, first-out (LIFO) basis. Any necessary lower-of-cost-or-market write-downs at year end are recorded as permanent adjustments to the LIFO cost basis. LIFO is used to better match current inventory costs with current revenues and to meet tax-conformity requirements. Costs include both direct and indirect expenditures incurred in bringing an item or product to its existing condition and location. Materials and supplies inventories are valued using the weighted-average-cost method. ▪ Fair Value Measurements —We categorize assets and liabilities measured at fair value into one of three different levels depending on the observability of the inputs employed in the measurement. Level 1 inputs are quoted prices in active markets for identical assets or liabilities. Level 2 inputs are inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly, through market-corroborated inputs. Level 3 inputs are unobservable inputs for the asset or liability that are used to measure fair value to the extent that relevant observable inputs are not available, and that reflect the assumptions we believe market participants would use when pricing an asset or liability for which there is little, if any, market activity at the measurement date. ▪ Derivative Instruments —Derivative instruments are recorded on the balance sheet at fair value. We have elected to net derivative assets and liabilities with the same counterparty on the balance sheet if the right of offset exists and certain other criteria are met. We also net collateral payables or receivables against derivative assets and derivative liabilities, respectively. Recognition and classification of the gain or loss that results from recording and adjusting a derivative to fair value depends on the purpose for issuing or holding the derivative. All realized and unrealized gains and losses from derivative instruments for which we do not apply hedge accounting are immediately recognized in our consolidated statement of income. Unrealized gains or losses from derivative instruments that qualify for and are designated as a cash flow hedge are recognized in other comprehensive income (loss) and appear on the balance sheet in accumulated other comprehensive income (loss) until the hedged transaction is recognized in earnings; however, to the extent the change in the fair value of a derivative instrument exceeds the change in the anticipated cash flows of the hedged transaction, the excess gain or loss is recognized immediately in earnings. ▪ Capitalized Interest —A portion of interest from external borrowings is capitalized on major projects with an expected construction period of one year or longer. Capitalized interest is added to the cost of the related asset, and is amortized over the useful life of the related asset. ▪ Loans and Long-Term Receivables —We enter into agreements with other parties to pursue business opportunities, which may require us to provide loans or advances to certain affiliated and non-affiliated companies. Loans are recorded when cash is transferred or seller financing is provided to the affiliated or non-affiliated company pursuant to a loan agreement. The loan balance will increase as interest is earned on the outstanding loan balance and will decrease as interest and principal payments are received. Interest is earned at the loan agreement’s stated interest rate. Loans and long-term receivables are assessed for impairment when events indicate the loan balance may not be fully recovered. ▪ Intangible Assets Other Than Goodwill —Intangible assets with finite useful lives are amortized using the straight-line method over their useful lives. Intangible assets with indefinite useful lives are not amortized but are tested at least annually for impairment. Each reporting period, we evaluate the remaining useful lives of intangible assets not being amortized to determine whether events and circumstances continue to support indefinite useful lives. Indefinite-lived intangible assets are considered impaired if their fair value is lower than their net book value. The fair value of intangible assets is determined based on quoted market prices in active markets, if available. If quoted market prices are not available, the fair value of intangible assets is determined based upon the present values of expected future cash flows using discount rates and other assumptions believed to be consistent with those used by principal market participants, or upon estimated replacement cost, if expected future cash flows from the intangible asset are not determinable. ▪ Goodwill —Goodwill represents the excess of the purchase price over the estimated fair value of the net assets acquired in a business combination. It is not amortized, but is tested for impairment annually and when events or changes in circumstance indicate that the fair value of a reporting unit with goodwill is below its carrying value. The impairment test requires allocating goodwill and other assets and liabilities to reporting units. The fair value of each reporting unit is determined and compared to the book value of the reporting unit. If the fair value of the reporting unit is less than the book value, an impairment is recognized for the amount by which the book value exceeds the reporting unit’s fair value. A goodwill loss cannot exceed the total amount of goodwill allocated to that reporting unit. For purposes of testing goodwill for impairment, we have three reporting units with goodwill balances: Transportation, Refining, and Marketing and Specialties. ▪ Depreciation and Amortization —Depreciation and amortization of properties, plants and equipment are determined by either the individual-unit-straight-line method or the group-straight-line method (for those individual units that are highly integrated with other units). ▪ Impairment of Properties, Plants and Equipment —Properties, plants and equipment (PP&E) used in operations are assessed for impairment whenever changes in facts and circumstances indicate a possible significant deterioration in the future cash flows expected to be generated by an asset group. If indicators of potential impairment exist, an undiscounted cash flow test is performed. If the sum of the undiscounted pre-tax cash flows is less than the carrying value of the asset group, including applicable liabilities, the carrying value of the PP&E included in the asset group is written down to estimated fair value through additional amortization or depreciation provisions and reported in the “Impairments” line on our consolidated statement of income in the period in which the determination of the impairment is made. Individual assets are grouped for impairment purposes at the lowest level for which identifiable cash flows are largely independent of the cash flows of other groups of assets (for example, at a refinery complex level). Because there is usually a lack of quoted market prices for long-lived assets, the fair value of impaired assets is typically determined using one or more of the following methods: the present values of expected future cash flows using discount rates and other assumptions believed to be consistent with those used by principal market participants; a market multiple of earnings for similar assets; or historical market transactions of similar assets, adjusted using principal market participant assumptions when necessary. Long-lived assets held for sale are accounted for at the lower of amortized cost or fair value, less cost to sell, with fair value determined using a binding negotiated price, if available, or present value of expected future cash flows as previously described. The expected future cash flows used for impairment reviews and related fair value calculations are based on estimated future volumes, prices, costs, margins and capital project decisions, considering all available evidence at the date of review. ▪ Impairment of Investments in Nonconsolidated Entities —Investments in nonconsolidated entities are assessed for impairment whenever changes in the facts and circumstances indicate a loss in value has occurred. When indicators exist, the fair value is estimated and compared to the investment carrying value. If any impairment is judgmentally determined to be other than temporary, the carrying value of the investment is written down to fair value. The fair value of the impaired investment is based on quoted market prices, if available, or upon the present value of expected future cash flows using discount rates and other assumptions believed to be consistent with those used by principal market participants and a market analysis of comparable assets, if appropriate. ▪ Maintenance and Repairs —Costs of maintenance and repairs, which are not significant improvements, are expensed when incurred. Major refinery maintenance turnarounds are expensed as incurred. ▪ Property Dispositions —When complete units of depreciable property are sold, the asset cost and related accumulated depreciation are eliminated, with any gain or loss reflected in the “Net gain on dispositions” line on our consolidated statement of income. When less than complete units of depreciable property are disposed of or retired, the difference between asset cost and salvage value is charged or credited to accumulated depreciation. ▪ Asset Retirement Obligations and Environmental Costs —The fair value of legal obligations to retire and remove long-lived assets are recorded in the period in which the obligation arises. When the liability is initially recorded, we capitalize this cost by increasing the carrying amount of the related PP&E. Over time, the liability is increased for the change in its present value, and the capitalized cost in PP&E is depreciated over the useful life of the related asset. If our estimate of the liability changes after initial recognition, we record an adjustment to the liability and PP&E. Environmental expenditures are expensed or capitalized, depending upon their future economic benefit. Expenditures relating to an existing condition caused by past operations, and those having no future economic benefit, are expensed. Liabilities for environmental expenditures are recorded on an undiscounted basis (unless acquired in a business combination) when environmental assessments or cleanups are probable and the costs can be reasonably estimated. Recoveries of environmental remediation costs from other parties, such as state reimbursement funds, are recorded as assets when their receipt is probable and estimable. ▪ Guarantees —The fair value of a guarantee is determined and recorded as a liability at the time the guarantee is given. The initial liability is subsequently reduced as we are released from exposure under the guarantee. We amortize the guarantee liability over the relevant time period, if one exists, based on the facts and circumstances surrounding each type of guarantee. In cases where the guarantee term is indefinite, we reverse the liability when we have information indicating the liability has essentially been relieved or amortize it over an appropriate time period as the fair value of our guarantee exposure declines over time. We amortize the guarantee liability to the related income statement line item based on the nature of the guarantee. When it becomes probable we will have to perform on a guarantee, we accrue a separate liability for the excess amount above the guarantee’s book value, if it is reasonably estimable, based on the facts and circumstances at that time. We reverse the fair value liability only when there is no further exposure under the guarantee. ▪ Share-Based Compensation —We recognize share-based compensation expense over the shorter of: (1) the service period (i.e., the stated period of time required to earn the award); or (2) the period beginning at the start of the service period and ending when an employee first becomes eligible for retirement, but not less than six months as this is the minimum period of time required for an award not to be subject to forfeiture. Our equity-classified programs generally provide accelerated vesting (i.e., a waiver of the remaining period of service required to earn an award) for awards held by employees at the time they become eligible for retirement (at age 55 with 5 years of service). We have elected to recognize expense on a straight-line basis over the service period for the entire award, irrespective of whether the award was granted with ratable or cliff vesting, and elected to recognize forfeiture reversals of awards when they occur. ▪ Income Taxes —Income taxes are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. Interest related to unrecognized income tax benefits is reflected in interest expense, and penalties in operating expenses. ▪ Taxes Collected from Customers and Remitted to Governmental Authorities —Excise taxes are reported gross within sales and other operating revenues and taxes other than income taxes, while other sales and value-added taxes are recorded net in taxes other than income taxes. ▪ Treasury Stock —We record treasury stock purchases at cost, which includes incremental direct transaction costs. Amounts are recorded as reductions in stockholders’ equity in the consolidated balance sheet.

Changes in Accounting Principle

Changes in Accounting Principles	12 Months Ended
	Dec. 31, 2017
Changes in Accounting Principles [Abstract]
Changes in Accounting Principles	Changes in Accounting Principles Effective January 1, 2017, we early adopted Financial Accounting Standards Board (FASB) Accounting Standards Update (ASU) No. 2017-04, “Intangibles—Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment,” which eliminated the second step from the goodwill impairment test. Under the revised test, an entity should perform its goodwill impairment tests by comparing the fair value of a reporting unit with its carrying amount. An entity should recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. This ASU was applied prospectively to goodwill impairment tests performed on or after January 1, 2017. Effective January 1, 2017, we early adopted ASU No. 2016-18, “Statement of Cash Flows (Topic 230): Restricted Cash.” The update clarified the classification and presentation of changes in restricted cash. The ASU requires that a statement of cash flows explain the change during the period in the total of cash, cash equivalents and amounts generally described as restricted cash and restricted cash equivalents. Adoption of this ASU on a retrospective basis did not have a material impact on our financial statements. See Note 23—Cash Flow Information for more information. Effective January 1, 2017, we early adopted ASU No. 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments.” The update clarified how certain cash receipts and cash payments should be presented and classified in the statement of cash flows. In addition, the ASU clarified that when cash receipts and cash payments have aspects of more than one class of cash flows and cannot be separated, classification will depend on the predominant source or use. Adoption of this ASU on a retrospective basis did not have a material impact on our financial statements. Effective January 1, 2017, we adopted ASU No. 2016-09, “Compensation—Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting,” which simplified several aspects of the accounting for share-based payment award transactions, including accounting for income taxes and classification of excess tax benefits on the statement of cash flows, forfeitures and minimum statutory tax withholding requirements. Adoption of this ASU on a prospective basis did not materially impact our financial position, results of operations, or cash flows. We account for forfeitures of awards when they occur and excess tax benefits, which were previously reported in cash flows from financing activities, are now reported in cash flows from operating activities. In June 2014, the FASB issued ASU No. 2014-10, “Development Stage Entities (Topic 915): Elimination of Certain Financial Reporting Requirements, Including an Amendment to Variable Interest Entities (VIE) Guidance in Topic 810, Consolidation.” This update removed the definition of a development stage entity from the Master Glossary of the Accounting Standard Codification (ASC) and the related financial reporting requirements specific to development stage entities. This update was intended to reduce cost and complexity of financial reporting for entities that have not commenced planned principal operations. For financial reporting requirements other than the VIE guidance in ASC Topic 810, ASU No. 2014-10 was effective for annual and quarterly reporting periods of public entities beginning after December 15, 2014. For the financial reporting requirements related to VIEs in ASC Topic 810, ASU No. 2014-10 was effective for annual and quarterly reporting periods for public entities beginning after December 15, 2015. We adopted the provisions of this ASU related to the financial reporting requirements other than the VIE guidance effective January 1, 2015. We adopted the remaining provisions effective January 1, 2016.

Variable Interest Entities

Variable Interest Entities	12 Months Ended
	Dec. 31, 2017
Variable Interest Entities [Abstract]
Variable Interest Entities	Variable Interest Entities Consolidated VIEs In 2013, we formed Phillips 66 Partners LP (Phillips 66 Partners), a master limited partnership, to own, operate, develop and acquire primarily fee-based crude oil, refined petroleum products and NGL pipelines and terminals, as well as other midstream assets. We consolidate Phillips 66 Partners as we determined that Phillips 66 Partners is a VIE and we are the primary beneficiary. As general partner of Phillips 66 Partners, we have the ability to control its financial interests, as well as the ability to direct the activities of Phillips 66 Partners that most significantly impact its economic performance. See Note 27—Phillips 66 Partners LP , for additional information. The most significant assets of Phillips 66 Partners that are available to settle only its obligations, along with its most significant liabilities for which its creditors do not have recourse to Phillips 66’s general credit at December 31 were: Millions of Dollars 2017 2016 Cash and cash equivalents $ 185 2 Equity investments* 1,932 1,142 Net properties, plants and equipment 2,918 2,675 Long-term debt 2,920 2,396 * Included in “Investments and long-term receivables” on the Phillips 66 consolidated balance sheet. Non-Consolidated VIEs We hold variable interests in VIEs that have not been consolidated because we are not considered the primary beneficiary. Information on our significant non-consolidated VIEs follows. Merey Sweeny, L.P. (MSLP) is a limited partnership that owns a delayed coker and related facilities at the Sweeny Refinery. Under the agreements that governed the relationships between the former co-venturers in MSLP, certain defaults by Petróleos de Venezuela S.A. (PDVSA) with respect to supply of crude oil to the Sweeny Refinery triggered the right to acquire PDVSA’s 50 percent ownership interest in MSLP. The call right was exercised in August 2009. The exercise of the call right was challenged, and the dispute was arbitrated in our favor and subsequently litigated. Through February 7, 2017, we determined MSLP was a VIE and used the equity method of accounting because the exercise of the call right remained subject to legal challenge. MSLP was a VIE because, in securing lender consents in connection with our separation from ConocoPhillips in 2012 (the Separation), we provided a 100 percent debt guarantee to the lender of MSLP’s 8.85% senior notes. PDVSA did not participate in the debt guarantee. In our VIE assessment, this disproportionate debt guarantee, plus other liquidity support provided jointly by us and PDVSA independently of equity ownership, resulted in MSLP not being exposed to all potential losses. We determined we were not the primary beneficiary while the call exercise was subject to legal challenge, because under the partnership agreement, the co-venturers jointly directed the activities of MSLP that most significantly impacted economic performance. As discussed more fully in Note 5—Business Combinations , the exercise of the call right ceased to be subject to legal challenge in February 2017. At that point, we no longer considered MSLP a VIE and the entity became a consolidated subsidiary. We own a 25 percent interest in both Dakota Access, LLC (Dakota Access) and Energy Transfer Crude Oil Company, LLC (ETCO), which collectively own the Bakken Pipeline. These entities did not have sufficient equity at risk to fully fund the construction of all assets required for principal operations, and thus represented VIEs until operations began. We determined we were not the primary beneficiary because we and our co-venturer at the time jointly directed the activities of Dakota Access and ETCO that most significantly impact economic performance. In June 2017, these entities started commercial operations and were no longer considered VIEs. We use the equity method of accounting for these investments.

Inventories

Inventories	12 Months Ended
	Dec. 31, 2017
Inventory Disclosure [Abstract]
Inventories	Inventories Inventories at December 31 consisted of the following: Millions of Dollars 2017 2016 Crude oil and petroleum products $ 3,106 2,883 Materials and supplies 289 267 $ 3,395 3,150 Inventories valued on the LIFO basis totaled $2,980 million and $2,772 million at December 31, 2017 and 2016 , respectively. The estimated excess of current replacement cost over LIFO cost of inventories amounted to approximately $4.3 billion and $3.3 billion at December 31, 2017 and 2016 , respectively. Excluding the disposition of the Whitegate Refinery, which occurred in September 2016, certain planned reductions in inventory caused liquidations of LIFO inventory values during each of the three years ended December 31, 2017 . These liquidations increased net income by approximately $13 million in 2017 and decreased net income by approximately $68 million and $37 million in 2016 and 2015, respectively. In conjunction with the Whitegate Refinery disposition, the refinery’s LIFO inventory values were liquidated causing a decrease in net income of $62 million during 2016. This LIFO liquidation impact was included in the net gain recognized on the disposition.

Business Combinations

Business Combinations	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Business Combinations	Business Combinations MSLP owns a delayed coker and related facilities at the Sweeny Refinery. Prior to August 28, 2009, MSLP was owned 50/50 by ConocoPhillips and PDVSA. Under the agreements that governed the relationships between the partners, certain defaults by PDVSA with respect to supply of crude oil to the Sweeny Refinery triggered the right, exercised in August 2009, to acquire its 50 percent ownership interest in MSLP for a purchase price determined by a contractual formula. As the distributions PDVSA received from MSLP exceeded the amounts it contributed to MSLP, the contractual formula required no cash consideration for the acquisition. The exercise was challenged, and the dispute was arbitrated in our favor and subsequently litigated. While the dispute was being arbitrated and litigated, we continued to use the equity method of accounting for our 50 percent interest in MSLP. When the exercise of the call right ceased to be subject to legal challenge on February 7, 2017, we deemed that we had acquired PDVSA’s 50 percent share of MSLP and began accounting for MSLP as a consolidated subsidiary. Based on a third-party appraisal of the fair value of MSLP’s net assets, utilizing discounted cash flows and replacement costs, the acquisition of PDVSA’s 50 percent interest resulted in our recording a pre-tax gain of $423 million in the first quarter of 2017. This gain was included in the “Other income” line on our consolidated statement of income. The fair value of our original equity interest in MSLP immediately prior to the deemed acquisition was $145 million . As a result of the transaction, we recorded $318 million of restricted cash, $250 million of PP&E and $238 million of debt, as well as a net $93 million for the elimination of our equity investment in MSLP and net intercompany payables. Our acquisition accounting was finalized during the first quarter of 2017. The results of MSLP were included in our Refining segment until October 2017, when we contributed our 100 percent interest in MSLP to Phillips 66 Partners, which is included in our Midstream segment. See Note 27—Phillips 66 Partners LP for further discussion regarding the contribution. In November 2016, Phillips 66 Partners acquired NGL logistics assets located in southeast Louisiana, consisting of approximately 500 miles of pipelines and storage caverns connecting multiple fractionation facilities, refineries and a petrochemical facility. The acquisition provided an opportunity for fee-based growth in the Louisiana market within our Midstream segment. The acquisition was included in the “Capital expenditures and investments” line on our consolidated statement of cash flows. At the acquisition date, we recorded $183 million of PP&E and $3 million of goodwill. Our acquisition accounting was finalized during the first quarter of 2017, with no change to the provisional amounts recorded in 2016.

Assets Held for Sale or Sold

Assets Held for Sale or Sold	12 Months Ended
	Dec. 31, 2017
Disposal Group, Including Discontinued Operation, Additional Disclosures [Abstract]
Assets Held for Sale or Sold	Assets Held for Sale or Sold In September 2016, we completed the sale of the Whitegate Refinery and related marketing assets, which were included primarily in our Refining segment. The net carrying value of the assets at the time of their disposition was $135 million , which consisted of $127 million of inventory, other working capital, and PP&E; and $8 million of allocated goodwill. An immaterial gain was recognized in 2016 on the disposition. In February 2015, we completed the sale of the Bantry Bay terminal, which was included in our Refining segment. At the time of the disposition, the terminal had a net carrying value of $68 million , which primarily related to net PP&E. An immaterial gain was recognized in 2015 on this disposition. In July 2013, we completed the sale of the Immingham Combined Heat and Power Plant (ICHP), which was included in our Marketing and Specialties segment. A gain on this disposal was deferred at the time of the sale due to an indemnity provided to the buyer. We recognized the deferred gain in earnings as our exposure under the indemnity declined, beginning in the third quarter of 2014 and ending in the second quarter of 2015 when the indemnity expired. We recognized $242 million of the deferred gain during the year ended December 31, 2015.

Investments, Loans and Long-Ter

Investments, Loans and Long-Term Receivables	12 Months Ended
	Dec. 31, 2017
Equity Method Investments and Joint Ventures [Abstract]
Investments, Loans and Long-Term Receivables	Investments, Loans and Long-Term Receivables Components of investments, loans and long-term receivables at December 31 were: Millions of Dollars 2017 2016 Equity investments $ 13,733 13,102 Loans and long-term receivables 94 334 Other investments 114 98 $ 13,941 13,534 Equity Investments Affiliated companies in which we had a significant equity investment at December 31, 2017 , included: • WRB Refining LP (WRB)— 50 percent owned business venture with Cenovus Energy Inc. (Cenovus)—owns the Wood River and Borger refineries. • DCP Midstream, LLC (DCP Midstream)— 50 percent owned joint venture with Spectra Energy Corp, a wholly owned subsidiary of Enbridge Inc.—owns and operates gas plants, gathering systems, storage facilities and fractionation plants, including through its investment in DCP Midstream, LP (DCP Partners). • Chevron Phillips Chemical Company LLC (CPChem)— 50 percent owned joint venture with Chevron U.S.A. Inc., an indirect wholly owned subsidiary of Chevron Corporation—manufactures and markets petrochemicals and plastics. • Rockies Express Pipeline LLC (REX)— 25 percent owned joint venture with Tallgrass Energy Partners L.P.—owns and operates a natural gas pipeline system from Colorado to Ohio. • DCP Sand Hills Pipeline, LLC (Sand Hills)—Phillips 66 Partners’ 33 percent owned joint venture with DCP Partners—owns and operates NGL pipeline systems from the Permian and Eagle Ford basins to Mont Belvieu, Texas. • DCP Southern Hills Pipeline, LLC (Southern Hills)—Phillips 66 Partners’ 33 percent owned joint venture with DCP Partners—owns and operates NGL pipeline systems from the Midcontinent region to Mont Belvieu, Texas. • Dakota Access and ETCO—Phillips 66 Partners’ two 25 percent owned joint ventures with Energy Transfer Partners L.P. (ETP) and MarEn Bakken Company LLC. Dakota Access owns a pipeline system that delivers crude oil from the Bakken/Three Forks production area in North Dakota to Patoka, Illinois, and ETCO owns a connecting crude oil pipeline system from Patoka, Illinois, to Nederland, Texas. Collectively, these two pipeline systems form the Bakken Pipeline, which is operated by ETP. Summarized 100 percent financial information for all equity method investments in affiliated companies, combined, was: Millions of Dollars 2017 2016 2015 Revenues $ 35,523 30,605 33,126 Income before income taxes 3,956 3,206 3,180 Net income 3,764 2,960 3,158 Current assets 7,325 7,097 6,024 Noncurrent assets 49,950 50,163 46,047 Current liabilities 5,248 5,173 4,130 Noncurrent liabilities 13,743 13,709 11,493 Noncontrolling interests 2,549 2,260 2,404 At December 31, 2017 , retained earnings included approximately $2,320 million related to the undistributed earnings of affiliated companies. Dividends received from affiliates were $1,270 million , $616 million , and $1,769 million in 2017 , 2016 and 2015 , respectively. WRB WRB’s operating assets consist of the Wood River and Borger refineries, located in Roxana, Illinois, and Borger, Texas, respectively, for which we are the operator and managing partner. As a result of our contribution of these two assets to WRB, a basis difference was created because the fair value of the contributed assets recorded by WRB exceeded their historical book value. The difference is primarily amortized and recognized as a benefit evenly over a period of 26 years , which was the estimated remaining useful life of the refineries’ PP&E at the closing date. At December 31, 2017 , the book value of our investment in WRB was $2,269 million , and the basis difference was $2,787 million . Equity earnings in 2017 , 2016 and 2015 were increased by $186 million , $185 million and $218 million , respectively, due to amortization of the basis difference. In the first quarter of 2017, we received payment of the $75 million outstanding principal balance of a partner loan we made to WRB in 2016. This cash inflow was included in the “Collection of advances/loans—related parties” line on our consolidated statement of cash flows. DCP Midstream DCP Midstream owns and operates gas plants, gathering systems, storage facilities and fractionation plants, primarily through its investment in DCP Partners. DCP Midstream markets a portion of its NGL to us and CPChem under supply agreements, the primary production commitment of which began a ratable wind-down period in December 2014 and expires in January 2019. This purchase commitment is on an “if-produced, will-purchase” basis. NGL is purchased under this agreement at various published market index prices, less transportation and fractionation fees. At December 31, 2017 , the book value of our investment in DCP Midstream was $2,227 million , and the basis difference was $54 million . In 2015, we contributed $1.5 billion in cash to DCP Midstream as a capital contribution. Our co-venturer contributed its interests in Sand Hills and Southern Hills as a capital contribution equal in value to ours. Our capital contribution was included in the “Capital expenditures and investments” line on our consolidated statement of cash flows. CPChem CPChem manufactures and markets petrochemicals and plastics. We have multiple supply and purchase agreements in place with CPChem, ranging in initial terms from one to 99 years, with extension options. These agreements cover sales and purchases of refined products, solvents, and petrochemical and NGL feedstocks, as well as fuel oils and gases. All products are purchased and sold under specified pricing formulas based on various published pricing indices. At December 31, 2017 , the book value of our equity method investment in CPChem was $6,222 million . REX REX owns a natural gas pipeline that runs from Meeker, Colorado, to Clarington, Ohio. At December 31, 2017 , the book value of our equity method investment in REX was $445 million , and the basis difference was $376 million . The basis difference was created by historical impairment charges we recorded to our investment. In 2015, we contributed $112 million to REX to cover our 25 percent share of a $450 million debt repayment. Our capital contribution was included in the “Capital expenditures and investments” line on our consolidated statement of cash flows. Sand Hills The Sand Hills pipeline is a fee-based pipeline that transports NGL from the Permian Basin and Eagle Ford Shale to facilities along the Texas Gulf Coast and the Mont Belvieu market hub. At December 31, 2017 , the book value of Phillips 66 Partners’ equity investment in Sand Hills was $515 million . Southern Hills The Southern Hills pipeline is a fee-based pipeline that transports NGL from the Midcontinent to facilities along the Texas Gulf Coast and the Mont Belvieu market hub. At December 31, 2017 , the book value of Phillips 66 Partners’ investment in Southern Hills was $209 million , and the basis difference was $94 million . Dakota Access and ETCO The Dakota Access and ETCO joint ventures were created to construct pipeline systems that collectively form the Bakken Pipeline. The Bakken Pipeline went into commercial service in June 2017, and delivers crude oil produced in the Bakken/Three Forks production area of North Dakota to market centers in the Midwest and the Gulf Coast. In October 2017, these investments were contributed to Phillips 66 Partners as discussed further in Note 27—Phillips 66 Partners LP . At December 31, 2017 , the aggregate book value of Phillips 66 Partners’ investments in Dakota Access and ETCO was $621 million , and the basis difference was $53 million . In May 2016, we and our co-venturer at the time, executed agreements under which we and our co-venturer would loan Dakota Access and ETCO up to a maximum of $2,256 million and $227 million , respectively, with the amounts loaned by us and our co-venturer being proportionate to our ownership interests (Sponsor Loans). In August 2016, Dakota Access and ETCO secured a $2.5 billion facility (Facility) with a syndicate of financial institutions on a limited recourse basis with certain guarantees, and the outstanding Sponsor Loans were repaid. Allowable draws under the Facility were initially reduced and finally suspended in September 2016 pending resolution of permitting delays. As a result, Dakota Access and ETCO resumed making draws under the Sponsor Loans. The maximum amounts that could be loaned under the Sponsor Loans were reduced in September 2016, to $1,411 million for Dakota Access and $76 million for ETCO. At December 31, 2016 , Dakota Access and ETCO had $976 million and $22 million , respectively, outstanding under the Sponsor Loans. Our 25 percent share of those loans was $244 million and $6 million , respectively. In February 2017, the Sponsor Loans were repaid in their entirety when draws resumed under the Facility. These cash inflows were included in the “Collection of advances/loans—related parties” line on our consolidated statement of cash flows.

Properties, Plants and Equipmen

Properties, Plants and Equipment	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Properties, Plants and Equipment	Properties, Plants and Equipment Our investment in PP&E is recorded at cost. Investments in refining and processing facilities are generally depreciated on a straight-line basis over a 25 -year life, pipeline assets over a 45 -year life and terminal assets over a 33 -year life. The company’s investment in PP&E, with the associated accumulated depreciation and amortization (Accum. D&A), at December 31 was: Millions of Dollars 2017 2016 Gross PP&E Accum. D&A Net PP&E Gross PP&E Accum. D&A Net PP&E Midstream $ 8,849 1,853 6,996 8,179 1,579 6,600 Chemicals — — — — — — Refining 22,144 8,987 13,157 21,152 8,197 12,955 Marketing and Specialties 1,658 909 749 1,451 776 675 Corporate and Other 1,091 533 558 1,207 582 625 $ 33,742 12,282 21,460 31,989 11,134 20,855

Goodwill and Intangibles

Goodwill and Intangibles	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangibles	Goodwill and Intangibles Goodwill The carrying amount of goodwill by segment at December 31 was: Millions of Dollars Midstream Refining Marketing and Specialties Total Balance at January 1, 2016 $ 623 1,813 839 3,275 Goodwill assigned to acquisitions 3 — — 3 Goodwill allocated to dispositions — (8 ) — (8 ) Balance at December 31, 2016 626 1,805 839 3,270 Adjustments — — — — Balance at December 31, 2017 $ 626 1,805 839 3,270 Intangible Assets The gross carrying value of indefinite-lived intangible assets at December 31 consisted of the following: Millions of Dollars 2017 2016 Trade names and trademarks $ 503 503 Refinery air and operating permits 252 260 Other 1 1 $ 756 764 At December 31, 2017 , the net book value of our amortized intangible assets was $120 million , which included accumulated amortization of $173 million . At December 31, 2016 , the net book value of our amortized intangible assets was $124 million , which included accumulated amortization of $152 million . Amortization expense was $21 million , $18 million and $13 million in 2017 , 2016 and 2015 , respectively, and is expected to be less than $20 million per year in future years.

Asset Retirement Obligations an

Asset Retirement Obligations and Accrued Environmental Costs	12 Months Ended
	Dec. 31, 2017
Asset Retirement Obligation and Accrual for Environmental Cost Disclosure [Abstract]
Asset Retirement Obligations and Accrued Environmental Costs	Asset Retirement Obligations and Accrued Environmental Costs Asset retirement obligations and accrued environmental costs at December 31 were: Millions of Dollars 2017 2016 Asset retirement obligations $ 268 244 Accrued environmental costs 458 496 Total asset retirement obligations and accrued environmental costs 726 740 Asset retirement obligations and accrued environmental costs due within one year* (85 ) (85 ) Long-term asset retirement obligations and accrued environmental costs $ 641 655 * Classified as a current liability on the consolidated balance sheet, under the caption “Other accruals.” Asset Retirement Obligations We have asset retirement obligations that we are required to perform under law or contract once an asset is permanently taken out of service. Most of these obligations are not expected to be paid until many years in the future and are expected to be funded from general company resources at the time of removal. Our largest individual obligations involve asbestos abatement at refineries. During 2017 and 2016 , our overall asset retirement obligation changed as follows: Millions of Dollars 2017 2016 Balance at January 1 $ 244 251 Accretion of discount 10 9 Changes in estimates of existing obligations 17 10 Spending on existing obligations (14 ) (15 ) Property dispositions — (5 ) Foreign currency translation 11 (6 ) Balance at December 31 $ 268 244 Accrued Environmental Costs The $38 million decrease in total accrued environmental costs in 2017 was due to payments and settlements during the year, which exceeded new accruals, accrual adjustments and accretion. Of our total accrued environmental costs at December 31, 2017, $222 million was primarily related to cleanup at domestic refineries and underground storage tanks at U.S. service stations; $187 million was associated with nonoperator sites; and $49 million was related to sites at which we have been named a potentially responsible party under federal or state laws. A large portion of our expected environmental expenditures have been discounted as these obligations were acquired in various business combinations. Expected expenditures for acquired environmental obligations were discounted using a weighted-average 5 percent discount factor, resulting in an accrued balance for acquired environmental liabilities of $268 million at December 31, 2017 . The expected future undiscounted payments related to the portion of the accrued environmental costs that have been discounted are: $18 million in 2018 , $46 million in 2019 , $30 million in 2020 , $16 million in 2021 , $16 million in 2022 , and $216 million for all future years after 2022 .

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Earnings Per Share	Earnings Per Share The numerator of basic earnings per share (EPS) is net income attributable to Phillips 66, reduced by noncancelable dividends paid on unvested share-based employee awards during the vesting period (participating securities). The denominator of basic EPS is the sum of the daily weighted-average number of common shares outstanding during the periods presented and fully vested stock and unit awards that have not yet been issued as common stock. The numerator of diluted EPS is also based on net income attributable to Phillips 66, which is reduced only by dividend equivalents paid on participating securities for which the dividends are more dilutive than the participation of the awards in the earnings of the periods presented. To the extent unvested stock, unit or option awards and vested unexercised stock options are dilutive, they are included with the weighted-average common shares outstanding in the denominator. Treasury stock is excluded from the denominator in both basic and diluted EPS. 2017 2016 2015 Basic Diluted Basic Diluted Basic Diluted Amounts Attributed to Phillips 66 Common Stockholders (millions) : Net income attributable to Phillips 66 $ 5,106 5,106 1,555 1,555 4,227 4,227 Income allocated to participating securities (6 ) — (6 ) (5 ) (6 ) — Net income available to common stockholders $ 5,100 5,106 1,549 1,550 4,221 4,227 Weighted-average common shares outstanding (thousands) : 511,268 515,090 523,250 527,531 537,602 542,355 Effect of share-based compensation 3,822 3,418 4,281 2,535 4,753 4,622 Weighted-average common shares outstanding—EPS 515,090 518,508 527,531 530,066 542,355 546,977 Earnings Per Share of Common Stock (dollars) $ 9.90 9.85 2.94 2.92 7.78 7.73

Debt

Debt	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Debt	Debt Long-term debt at December 31 was: Millions of Dollars 2017 2016 2.950% Senior Notes due 2017 $ — 1,500 4.300% Senior Notes due 2022 2,000 2,000 4.650% Senior Notes due 2034 1,000 1,000 5.875% Senior Notes due 2042 1,500 1,500 4.875% Senior Notes due 2044 1,500 1,500 Phillips 66 Partners 2.646% Senior Notes due 2020 300 300 Phillips 66 Partners 3.605% Senior Notes due 2025 500 500 Phillips 66 Partners 3.550% Senior Notes due 2026 500 500 Phillips 66 Partners 3.750% Senior Notes due 2028 500 — Phillips 66 Partners 4.680% Senior Notes due 2045 450 300 Phillips 66 Partners 4.900% Senior Notes due 2046 625 625 Floating-rate notes due 2019 at 2.009% at year-end 2017 300 — Floating-rate notes due 2020 at 2.109% at year-end 2017 300 — Term loan due 2020 at 2.469% at year-end 2017 450 — Note payable to MSLP due 2020 at 7.00%* — 68 Industrial Development Bonds due 2018 through 2021 at 0.80%-2.09% at year-end 2017 and 0.57%-0.81% at year-end 2016* 100 50 Phillips 66 Partners revolving credit facility due 2021 at 1.98% at year-end 2016 — 210 Other 1 1 Debt at face value 10,026 10,054 Capitalized leases 192 188 Net unamortized discounts and debt issuance costs (108 ) (104 ) Total debt 10,110 10,138 Short-term debt (41 ) (550 ) Long-term debt $ 10,069 9,588 * In February 2017, MSLP became a consolidated subsidiary, see Note 5—Business Combinations. Maturities of borrowings outstanding at December 31, 2017, inclusive of net unamortized discounts and debt issuance costs, for each of the years from 2018 through 2022 are $41 million , $314 million , $1,084 million , $62 million and $2,003 million , respectively. Debt Issuances In October 2017, Phillips 66 Partners closed on a public offering of $650 million aggregate principal amount of senior notes, consisting of $500 million of 3.750% Senior Notes due 2028 and $150 million of 4.680% Senior Notes due 2045. Interest on the 3.750% Senior Notes due 2028 is payable semiannually in arrears on March 1 and September 1 of each year, commencing on March 1, 2018. Interest on the 4.680% Senior Notes due 2045 is payable semiannually in arrears on February 15 and August 15 of each year. In April 2017, Phillips 66 completed a private offering of $600 million aggregate principal amount of unsecured notes, consisting of $300 million of Notes due 2019 and $300 million of Notes due 2020. Interest on these notes is a floating rate equal to three-month London Interbank Offered Rate (LIBOR) plus 0.65% per annum for the 2019 Notes and three-month LIBOR plus 0.75% per annum for the 2020 Notes. Interest on both series of notes is payable quarterly in arrears on January 15, April 15, July 15 and October 15, commencing in July 2017. The 2019 Notes mature on April 15, 2019, and the 2020 Notes mature on April 15, 2020. The notes are guaranteed by Phillips 66 Company, a 100-percent-owned subsidiary. Also in April 2017, Phillips 66 entered into term loan facilities with an aggregate borrowing amount of $900 million , consisting of a $450 million 364 -day facility and a $450 million three -year facility. Interest on the term loans is a floating rate based on either the Eurodollar rate or the reference rate, plus a margin determined by our long-term credit ratings. In February 2017, as part of the consolidation of MSLP, Phillips 66 assumed $135 million of 8.85% Senior Notes due in 2019 and $100 million of tax-exempt bonds due between 2018 and 2021. See Note 5—Business Combinations for additional information regarding the consolidation of MSLP. Debt Repayments In October 2017, as part of a contribution of assets to Phillips 66 Partners, Phillips 66 Partners assumed the $450 million term loan outstanding under the 364 -day facility originally issued in April 2017, and subsequently repaid the loan. See Note 27—Phillips 66 Partners LP for additional information. In May 2017, we repaid $1,500 million of 2.950% Senior Notes upon maturity with the funding from the April 2017 debt issuances discussed above. In addition, we repaid $135 million of MSLP 8.85% Senior Notes due in 2019 originally recorded in February 2017 as part of the consolidation of MSLP. See Note 5—Business Combinations for additional information regarding MSLP. During 2017, Phillips 66 Partners repaid all outstanding borrowings under its $750 million revolving credit facility. Credit Facilities and Commercial Paper Phillips 66 has a $5.0 billion revolving credit facility that extends until October 2021. This facility may be used for direct bank borrowings, as support for issuances of letters of credit, or as support for our commercial paper program. The facility is with a broad syndicate of financial institutions and contains covenants that we consider usual and customary for an agreement of this type for comparable commercial borrowers, including a maximum consolidated net debt-to-capitalization ratio of 60 percent . The agreement has customary events of default, such as nonpayment of principal when due; nonpayment of interest, fees or other amounts; violation of covenants; cross-payment default and cross-acceleration (in each case, to indebtedness in excess of a threshold amount); and a change of control. Borrowings under the facility will incur interest at the LIBOR plus a margin based on the credit rating of our senior unsecured long-term debt as determined from time to time by Standard & Poor’s Ratings Services and Moody’s Investors Service. The facility also provides for customary fees, including administrative agent fees and commitment fees. At December 31, 2017, no amount had been drawn under this revolving credit agreement. We have a $5.0 billion commercial paper program for short-term working capital needs that is supported by our revolving credit facility. Commercial paper maturities are generally limited to 90 days. At December 31, 2017, we had no borrowings under our commercial paper program. Phillips 66 Partners has a $750 million revolving credit facility that extends until October 2021. The Phillips 66 Partners facility is with a broad syndicate of financial institutions. At December 31, 2017, Phillips 66 Partners had no borrowings outstanding under this facility.

Guarantees

Guarantees	12 Months Ended
	Dec. 31, 2017
Guarantees [Abstract]
Guarantees	Guarantees At December 31, 2017 , we were liable for certain contingent obligations under various contractual arrangements as described below. We recognize a liability for the fair value of our obligation as a guarantor for newly issued or modified guarantees. Unless the carrying amount of the liability is noted below, we have not recognized a liability either because the guarantees were issued prior to December 31, 2002, or because the fair value of the obligation is immaterial. In addition, unless otherwise stated, we are not currently performing with any significance under the guarantee and expect future performance to be either immaterial or have only a remote chance of occurrence. Guarantees of Joint-Venture Debt In December 2016, as part of the restructuring within DCP Midstream, we issued a guarantee, effective January 1, 2017, to support the debt DCP Midstream issued in the first quarter of 2017. At December 31, 2017, the maximum potential amount of future payments to third parties under the guarantee is estimated to be $175 million . Payment would be required if DCP Midstream defaults on this debt obligation, which matures in 2019. At December 31, 2017 , we had other guarantees outstanding for our portion of certain joint-venture debt obligations, which have remaining terms of up to 8 years. The maximum potential amount of future payments to third parties under these guarantees is approximately $133 million . Payment would be required if a joint venture defaults on its debt obligations. Other Guarantees Under the operating lease agreement on our headquarters facility in Houston, Texas, we have a residual value guarantee with a maximum future exposure of $554 million . The operating lease has a term of five years and provides us the option, at the end of the lease term, to request to renew the lease, purchase the facility or assist the lessor in marketing it for resale. We also have residual value guarantees associated with railcar and airplane leases with maximum future exposures totaling $305 million . Based on third-party appraisals of the railcars’ fair value at the end of their lease terms, we estimated a total residual value deficiency of $109 million and recognized $28 million as expense in 2016. During 2017, we recognized an additional $45 million of expense related to the residual value deficiency. In October 2017, upon maturity of one of our railcar leases, $53 million of the total residual value deficiency of $109 million was settled. The remaining residual value deficiency of $36 million remaining at December 31, 2017, will be recognized on a straight-line basis through May 2019. Indemnifications Over the years, we have entered into various agreements to sell ownership interests in certain corporations, joint ventures and assets that gave rise to indemnification. Agreements associated with these sales include indemnifications for taxes, litigation, environmental liabilities, permits and licenses, and employee claims, as well as real estate indemnity against tenant defaults. The provisions of these indemnifications vary greatly. The majority of these indemnifications are related to environmental issues, which generally have indefinite terms and potentially unlimited exposure. The carrying amount recorded for indemnifications at December 31, 2017 , was $193 million . We amortize the indemnification liability over the relevant time period, if one exists, based on the facts and circumstances surrounding each type of indemnity. In cases where the indemnification term is indefinite, we will reverse the liability when we have information to support that the liability was essentially relieved or amortize the liability over an appropriate time period as the fair value of our indemnification exposure declines. Although it is reasonably possible future payments may exceed amounts recorded, due to the nature of the indemnifications, it is not possible to make a reasonable estimate of the maximum potential amount of future payments. Included in the recorded carrying amount were $104 million of environmental accruals for known contamination at December 31, 2017 . For additional information about environmental liabilities, see Note 10—Asset Retirement Obligations and Accrued Environmental Costs and Note 14—Contingencies and Commitments . Indemnification and Release Agreement In 2012, in connection with the Separation, we entered into the Indemnification and Release Agreement with ConocoPhillips. This agreement governs the treatment between ConocoPhillips and us of matters relating to indemnification, insurance, litigation responsibility and management, and litigation document sharing and cooperation arising in connection with the Separation. Generally, the agreement provides for cross-indemnities principally designed to place financial responsibility for the obligations and liabilities of our business with us and financial responsibility for the obligations and liabilities of ConocoPhillips’ business with ConocoPhillips. The agreement also establishes procedures for handling claims subject to indemnification and related matters.

Contingencies and Commitments

Contingencies and Commitments	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Contingencies and Commitments	Contingencies and Commitments A number of lawsuits involving a variety of claims that arose in the ordinary course of business have been filed against us or are subject to indemnifications provided by us. We also may be required to remove or mitigate the effects on the environment of the placement, storage, disposal or release of certain chemical, mineral and petroleum substances at various active and inactive sites. We regularly assess the need for financial recognition or disclosure of these contingencies. In the case of all known contingencies (other than those related to income taxes), we accrue a liability when the loss is probable and the amount is reasonably estimable. If a range of amounts can be reasonably estimated and no amount within the range is a better estimate than any other amount, then the minimum of the range is accrued. We do not reduce these liabilities for potential insurance or third-party recoveries. If applicable, we accrue receivables for probable insurance or other third-party recoveries. In the case of income-tax-related contingencies, we use a cumulative probability-weighted loss accrual in cases where sustaining a tax position is less than certain. See Note 21—Income Taxes , for additional information about income-tax-related contingencies. Based on currently available information, we believe it is remote that future costs related to known contingent liability exposures will exceed current accruals by an amount that would have a material adverse impact on our consolidated financial statements. As we learn new facts concerning contingencies, we reassess our position both with respect to accrued liabilities and other potential exposures. Estimates particularly sensitive to future changes include contingent liabilities recorded for environmental remediation, tax and legal matters. Estimated future environmental remediation costs are subject to change due to such factors as the uncertain magnitude of cleanup costs, the unknown time and extent of such remedial actions that may be required, and the determination of our liability in proportion to that of other potentially responsible parties. Estimated future costs related to tax and legal matters are subject to change as events evolve and as additional information becomes available during the administrative and litigation processes. Environmental We are subject to international, federal, state and local environmental laws and regulations. When we prepare our consolidated financial statements, we record accruals for environmental liabilities based on management’s best estimates, using all information available at the time. We measure estimates and base contingent liabilities on currently available facts, existing technology, and presently enacted laws and regulations, taking into account stakeholder and business considerations. When measuring contingent environmental liabilities, we also consider our prior experience in remediation of contaminated sites, other companies’ cleanup experience, and data released by the U.S. Environmental Protection Agency (EPA) or other organizations. We consider unasserted claims in our determination of environmental liabilities, and we accrue them in the period they are both probable and reasonably estimable. Although liability for environmental remediation costs is generally joint and several for federal sites and frequently so for state sites, we are usually only one of many companies alleged to have liability at a particular site. Due to such joint and several liabilities, we could be responsible for all cleanup costs related to any site at which we have been designated as a potentially responsible party. We have been successful to date in sharing cleanup costs with other financially sound companies. Many of the sites at which we are potentially responsible are still under investigation by the EPA or the state agencies concerned. Prior to actual cleanup, those potentially responsible normally assess the site conditions, apportion responsibility and determine the appropriate remediation. In some instances, we may have no liability or may attain a settlement of liability. Where it appears that other potentially responsible parties may be financially unable to bear their proportional share, we consider this inability in estimating our potential liability, and we adjust our accruals accordingly. As a result of various acquisitions in the past, we assumed certain environmental obligations. Some of these environmental obligations are mitigated by indemnifications made by others for our benefit, although some of the indemnifications are subject to dollar and time limits. We are currently participating in environmental assessments and cleanups at numerous federal Superfund and comparable state sites. After an assessment of environmental exposures for cleanup and other costs, we make accruals on an undiscounted basis (except those pertaining to sites acquired in a business combination, which we record on a discounted basis) for planned investigation and remediation activities for sites where it is probable future costs will be incurred and these costs can be reasonably estimated. We have not reduced these accruals for possible insurance recoveries. In the future, we may be involved in additional environmental assessments, cleanups and proceedings. See Note 10—Asset Retirement Obligations and Accrued Environmental Costs , for a summary of our accrued environmental liabilities. Legal Proceedings Our legal organization applies its knowledge, experience and professional judgment to the specific characteristics of our cases, employing a litigation management process to manage and monitor the legal proceedings against us. Our process facilitates the early evaluation and quantification of potential exposures in individual cases and enables the tracking of those cases that have been scheduled for trial and/or mediation. Based on professional judgment and experience in using these litigation management tools and available information about current developments in all our cases, our legal organization regularly assesses the adequacy of current accruals and determines if adjustment of existing accruals, or establishment of new accruals, is required. Other Contingencies We have contingent liabilities resulting from throughput agreements with pipeline and processing companies not associated with financing arrangements. Under these agreements, we may be required to provide any such company with additional funds through advances and penalties for fees related to throughput capacity not utilized. At December 31, 2017 , we had performance obligations secured by letters of credit and bank guarantees of $773 million related to various purchase and other commitments incident to the ordinary conduct of business. Long-Term Throughput Agreements and Take-or-Pay Agreements We have certain throughput agreements and take-or-pay agreements in support of third-party financing arrangements. The agreements typically provide for crude oil transportation to be used in the ordinary course of our business. The aggregate amounts of estimated payments under these various agreements are $ 327 million annually for each of the years from 2018 through 2022 and $2,644 million in the aggregate for years 2023 and thereafter . Total payments under the agreements were $323 million in 2017 , $325 million in 2016 and $328 million in 2015 .

Derivatives and Financial Instr

Derivatives and Financial Instruments	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Derivatives and Financial Instruments	Derivatives and Financial Instruments Derivative Instruments We use financial and commodity-based derivative contracts to manage exposures to fluctuations in commodity prices, interest rates and foreign currency exchange rates, or to capture market opportunities. Because we do not apply hedge accounting for commodity derivative contracts, all realized and unrealized gains and losses from commodity derivative contracts are recognized in our consolidated statement of income. Gains and losses from derivative contracts held for trading not directly related to our physical business are reported net in the “Other income” line on our consolidated statement of income. Cash flows from all our derivative activity for the periods presented appear in the operating section on our consolidated statement of cash flows. Purchase and sales contracts with firm minimum notional volumes for commodities that are readily convertible to cash are recorded on our consolidated balance sheet as derivatives unless the contracts are eligible for, and we elect, the normal purchases and normal sales exception, whereby the contracts are recorded on an accrual basis. We generally apply the normal purchases and normal sales exception to eligible crude oil, refined products, NGL, natural gas and power commodity contracts to purchase or sell quantities we expect to use or sell in the normal course of business. All other derivative instruments are recorded at fair value on our consolidated balance sheet. For further information on the fair value of derivatives, see Note 16—Fair Value Measurements . Commodity Derivative Contracts —We sell into or receive supply from the worldwide crude oil, refined products, NGL, natural gas, and electric power markets, exposing our revenues, purchases, cost of operating activities and cash flows to fluctuations in the prices for these commodities. Generally, our policy is to remain exposed to the market prices of commodities; however, we use futures, forwards, swaps and options in various markets to balance physical systems, meet customer needs, manage price exposures on specific transactions, and do a limited, immaterial amount of trading not directly related to our physical business, all of which may reduce our exposure to fluctuations in market prices. We also use the market knowledge gained from these activities to capture market opportunities such as moving physical commodities to more profitable locations, storing commodities to capture seasonal or time premiums, and blending commodities to capture quality upgrades. The following table indicates the consolidated balance sheet line items that include the fair values of commodity derivative assets and liabilities. The balances in the following table are presented on a gross basis, before the effects of counterparty and collateral netting. However, we have elected to present our commodity derivative assets and liabilities with the same counterparty on a net basis on our consolidated balance sheet when the right of setoff exists. Millions of Dollars December 31, 2017 December 31, 2016 Commodity Derivatives Effect of Collateral Netting Net Carrying Value Presented on the Balance Sheet Commodity Derivatives Effect of Collateral Netting Net Carrying Value Presented on the Balance Sheet Assets Liabilities Assets Liabilities Assets Prepaid expenses and other current assets $ 43 (19 ) — 24 267 (154 ) — 113 Other assets 7 (3 ) — 4 5 (1 ) — 4 Liabilities Other accruals 699 (746 ) 21 (26 ) 474 (612 ) 73 (65 ) Other liabilities and deferred credits — (1 ) — (1 ) — (1 ) — (1 ) Total $ 749 (769 ) 21 1 746 (768 ) 73 51 At December 31, 2017 and 2016, there was no material cash collateral received or paid that was not offset on our consolidated balance sheet. The realized and unrealized gains (losses) incurred from commodity derivatives, and the line items where they appear on our consolidated statement of income, were: Millions of Dollars 2017 2016 2015 Sales and other operating revenues $ (247 ) (451 ) 162 Other income 27 29 58 Purchased crude oil and products (18 ) (62 ) 121 Net gain (loss) from commodity derivative activity $ (238 ) (484 ) 341 The following table summarizes our material net exposures resulting from outstanding commodity derivative contracts. These financial and physical derivative contracts are primarily used to manage price exposure on our underlying operations. The underlying exposures may be from non-derivative positions such as inventory volumes. Financial derivative contracts may also offset physical derivative contracts, such as forward sales contracts. The percentage of our derivative contract volumes expiring within the next 12 months was at least 98 percent at December 31, 2017 and 2016 . Open Position Long / (Short) 2017 2016 Commodity Crude oil, refined products and NGL (millions of barrels) (11 ) (18 ) Interest Rate Derivative Contracts —In 2016, we entered into interest rate swaps to hedge the variability of anticipated lease payments on our new headquarters. These monthly lease payments will vary based on monthly changes in the one-month LIBOR and changes, if any, in our credit rating over the five-year term of the lease. The pay-fixed, receive-floating interest rate swaps have an aggregate notional value of $ 650 million and end on April 25, 2021. They qualify for and are designated as cash-flow hedges. The aggregate net fair value of these swaps, which is included in the “Prepaid expenses and other current assets,” “Other assets” and “Other accruals” lines of our consolidated balance sheet, totaled $14 million and $8 million at December 31, 2017 and 2016, respectively. We report the effective portion of the mark-to-market gain or loss on our interest rate swaps designated as cash-flow hedges as a component of other comprehensive income (loss), and reclassify such gains and losses into earnings in the same period during which the hedged forecasted transaction affects earnings. Gains and losses due to ineffectiveness are recognized in general and administrative expenses. We did not have any material hedge ineffectiveness gain or loss for the years ended December 31, 2017 and 2016. Net realized losses from settlements of the swaps were immaterial for the years ended December 31, 2017 and 2016. We currently estimate that pre-tax gains of $2 million will be reclassified from accumulated other comprehensive income (loss) into general and administrative expenses during the next twelve months as the hedged transactions settle; however, the actual amounts that will be reclassified will vary based on changes in interest rates throughout 2018. Credit Risk Financial instruments potentially exposed to concentrations of credit risk consist primarily of over-the-counter (OTC) derivative contracts and trade receivables. The credit risk from our OTC derivative contracts, such as forwards and swaps, derives from the counterparty to the transaction. Individual counterparty exposure is managed within predetermined credit limits and includes the use of cash-call margins when appropriate, thereby reducing the risk of significant nonperformance. We also use futures, swaps and option contracts that have a negligible credit risk because these trades are cleared with an exchange clearinghouse and subject to mandatory margin requirements until settled. However, we are exposed to the credit risk of those exchange brokers for receivables arising from daily margin cash calls, as well as for cash deposited to meet initial margin requirements. Our trade receivables result primarily from the sale of products from, or related to, our refinery operations and reflect a broad national and international customer base, which limits our exposure to concentrations of credit risk. The majority of these receivables have payment terms of 30 days or less . We continually monitor this exposure and the creditworthiness of the counterparties and recognize bad debt expense based on historical write-off experience or specific counterparty collectability. Generally, we do not require collateral to limit the exposure to loss; however, we will sometimes use letters of credit, prepayments or master netting arrangements to mitigate credit risk with counterparties that both buy from and sell to us, as these agreements permit the amounts owed by us or owed to others to be offset against amounts due to us. Certain of our derivative instruments contain provisions that require us to post collateral if the derivative exposure exceeds a threshold amount. We have contracts with fixed threshold amounts and other contracts with variable threshold amounts that are contingent on our credit rating. The variable threshold amounts typically decline for lower credit ratings, while both the variable and fixed threshold amounts typically revert to zero if our credit ratings fall below investment grade. Cash is the primary collateral in all contracts; however, many contracts also permit us to post letters of credit as collateral. The aggregate fair values of all derivative instruments with such credit-risk-related contingent features that were in a liability position were not material at December 31, 2017 and 2016 .

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements Recurring Fair Value Measurements We carry certain assets and liabilities at fair value, which we measure at the reporting date using an exit price (i.e., the price that would be received to sell an asset or paid to transfer a liability), and disclose the quality of these fair values based on the valuation inputs used in these measurements under the following hierarchy: • Level 1: Fair value measured with unadjusted quoted prices from an active market for identical assets or liabilities. • Level 2: Fair value measured either with: (1) adjusted quoted prices from an active market for similar assets or liabilities; or (2) other valuation inputs that are directly or indirectly observable. • Level 3: Fair value measured with unobservable inputs that are significant to the measurement. We classify the fair value of an asset or liability based on the significance of its observable or unobservable inputs to the measurement. However, the fair value of an asset or liability initially reported as Level 3 will be subsequently reported as Level 2 if the unobservable inputs become inconsequential to its measurement or corroborating market data becomes available. Conversely, an asset or liability initially reported as Level 2 will be subsequently reported as Level 3 if corroborating market data becomes unavailable. For the year ended December 31, 2017, derivative assets with an aggregate value of $131 million and derivative liabilities with an aggregate value of $134 million were transferred to Level 1 from Level 2, as measured from the beginning of the reporting period. The measurements were reclassified within the fair value hierarchy due to the availability of unadjusted quoted prices from an active market. We used the following methods and assumptions to estimate the fair value of financial instruments: • Cash and cash equivalents —The carrying amount reported on our consolidated balance sheet approximates fair value. • Accounts and notes receivable — The carrying amount reported on our consolidated balance sheet approximates fair value. • Derivative instruments —We fair value our exchange-traded contracts based on quoted market prices obtained from the New York Mercantile Exchange, the Intercontinental Exchange or other exchanges, and classify them as Level 1 in the fair value hierarchy. When exchange-cleared contracts lack sufficient liquidity or are valued using either adjusted exchange-provided prices or non-exchange quotes, we classify those contracts as Level 2. OTC financial swaps and physical commodity forward purchase and sales contracts are generally valued using forward quotes provided by brokers and price index developers, such as Platts and Oil Price Information Service. We corroborate these quotes with market data and classify the resulting fair values as Level 2. When forward market prices are not available, we estimate fair value using the forward price of a similar commodity, adjusted for the difference in quality or location. In certain less liquid markets or for longer-term contracts, forward prices are not as readily available. In these circumstances, OTC swaps and physical commodity purchase and sales contracts are valued using internally developed methodologies that consider historical relationships among various commodities that result in management’s best estimate of fair value. We classify these contracts as Level 3. Financial OTC and physical commodity options are valued using industry-standard models that consider various assumptions, including quoted forward prices for commodities, time value, volatility factors and contractual prices for the underlying instruments, as well as other relevant economic measures. The degree to which these inputs are observable in the forward markets determines whether the options are classified as Level 2 or 3. We use a mid-market pricing convention (the mid-point between bid and ask prices). When appropriate, valuations are adjusted to reflect credit considerations, generally based on available market evidence. We determine the fair value of our interest rate swaps based on observed market valuations for interest rate swaps that have notionals, terms and pay and reset frequencies similar to ours. • Rabbi trust assets —These deferred compensation investments are measured at fair value using unadjusted quoted prices available from national securities exchanges and are therefore categorized as Level 1 in the fair value hierarchy. • Debt —The carrying amount of our floating-rate debt approximates fair value. The fair value of our fixed-rate debt is estimated based on observable market prices. The following tables display the fair value hierarchy for our material financial assets and liabilities either accounted for or disclosed at fair value on a recurring basis. These values are determined by treating each contract as the fundamental unit of account; therefore, derivative assets and liabilities with the same counterparty are shown on a gross basis in the hierarchy sections of these tables, before the effects of counterparty and collateral netting. These tables also show that our Level 3 activity was not material. We have master netting agreements for all of our exchange-cleared derivative instruments, the majority of our OTC derivative instruments, and certain physical commodity forward contracts (primarily pipeline crude oil deliveries). The following tables show the impact of these contracts in the column “Effect of Counterparty Netting.” The carrying values and fair values by hierarchy of our material financial instruments and commodity forward contracts, either carried or disclosed at fair value, including any effects of netting derivative assets with liabilities and netting collateral due to right of setoff or master netting agreements, were: Millions of Dollars December 31, 2017 Fair Value Hierarchy Total Fair Value of Gross Assets & Liabilities Effect of Counterparty Netting Effect of Collateral Netting Difference in Carrying Value and Fair Value Net Carrying Value Presented on the Balance Sheet Level 1 Level 2 Level 3 Commodity Derivative Assets Exchange-cleared instruments $ 333 395 — 728 (721 ) — — 7 Physical forward contracts — 20 1 21 — — — 21 Interest rate derivatives — 14 — 14 — — — 14 Rabbi trust assets 112 — — 112 N/A N/A — 112 $ 445 429 1 875 (721 ) — — 154 Commodity Derivative Liabilities Exchange-cleared instruments $ 369 373 — 742 (721 ) (21 ) — — Physical forward contracts — 23 4 27 — — — 27 Floating-rate debt — 1,150 — 1,150 N/A N/A — 1,150 Fixed-rate debt, excluding capital leases — 9,746 — 9,746 N/A N/A (978 ) 8,768 $ 369 11,292 4 11,665 (721 ) (21 ) (978 ) 9,945 Millions of Dollars December 31, 2016 Fair Value Hierarchy Total Fair Value of Gross Assets & Liabilities Effect of Counterparty Netting Effect of Collateral Netting Difference in Carrying Value and Fair Value Net Carrying Value Presented on the Balance Sheet Level 1 Level 2 Level 3 Commodity Derivative Assets Exchange-cleared instruments $ 273 371 — 644 (628 ) — — 16 OTC instruments — 6 — 6 (1 ) — — 5 Physical forward contracts — 94 2 96 — — — 96 Interest rate derivatives — 8 — 8 — — — 8 Rabbi trust assets 97 — — 97 N/A N/A — 97 $ 370 479 2 851 (629 ) — — 222 Commodity Derivative Liabilities Exchange-cleared instruments $ 249 452 — 701 (628 ) (73 ) — — OTC instruments — 1 — 1 (1 ) — — — Physical forward contracts — 61 5 66 — — — 66 Floating-rate debt — 260 — 260 N/A N/A — 260 Fixed-rate debt, excluding capital leases — 10,260 — 10,260 N/A N/A (570 ) 9,690 $ 249 11,034 5 11,288 (629 ) (73 ) (570 ) 10,016 The rabbi trust assets are recorded in the “Investments and long-term receivables” line and floating-rate and fixed-rate debt are recorded in the “Short-term debt” and “Long-term debt” lines on our consolidated balance sheet. For information regarding the location of our commodity derivative assets and liabilities on our consolidated balance sheet, see the first table in Note 15—Derivatives and Financial Instruments . Nonrecurring Fair Value Measurements See Note 5—Business Combinations for information on the remeasurement of our investment in MSLP to fair value. During the years ended December 31, 2017 , and 2016, there were no other material nonrecurring fair value remeasurements of assets subsequent to their initial recognition.

Equity

Equity	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Equity	Equity Preferred Stock We have 500 million shares of preferred stock authorized, with a par value of $0.01 per share, none of which have been issued. Treasury Stock Since July 2012, our Board of Directors has, at various times, authorized repurchases of our outstanding common stock which aggregate to a total authorization of up to $12.0 billion . The shares will be repurchased from time to time in the open market at the company’s discretion, subject to market conditions and other factors, and in accordance with applicable regulatory requirements. We are not obligated to acquire any particular amount of common stock and may commence, suspend or discontinue purchases at any time or from time to time without prior notice. Since the inception of our share repurchases in 2012, through December 31, 2017 , we have repurchased a total of 124,142,530 shares at an aggregate cost of $9.0 billion . Shares of stock repurchased are held as treasury shares. In 2014, we completed the exchange of our flow improver business for shares of Phillips 66 common stock owned by the other party to the transaction. We received 17,422,615 shares of our common stock with a fair value at the time of the exchange of $1.35 billion . Common Stock Dividends On February 7, 2018 , our Board of Directors declared a quarterly cash dividend of $0.70 per common share, payable March 1, 2018 , to holders of record at the close of business on February 20, 2018 . Noncontrolling Interests Our noncontrolling interests primarily represent issuances of common and preferred units to the public by Phillips 66 Partners. See Note 27—Phillips 66 Partners LP , for information on Phillips 66 Partners.

Leases

Leases	12 Months Ended
	Dec. 31, 2017
Leases [Abstract]
Leases	Leases We lease ocean transport vessels, tugboats, barges, pipelines, railcars, service station sites, computers, office buildings, corporate aircraft, land and other facilities and equipment. Certain leases include escalation clauses for adjusting rental payments to reflect changes in price indices, as well as renewal options and/or options to purchase the leased property. There are no significant restrictions imposed on us by the leasing agreements with regard to dividends, asset dispositions or borrowing ability. Our capital lease obligations relate primarily to the lease of an oil terminal in the United Kingdom. The lease obligation is subject to foreign currency translation adjustments each reporting period. The total net PP&E recorded for capital leases was $210 million and $208 million at December 31, 2017 and 2016 , respectively. Future minimum lease payments at December 31, 2017 , for operating and capital lease obligations were: Millions of Dollars Capital Lease Obligations Operating Lease Obligations* 2018 $ 22 533 2019 22 420 2020 18 306 2021 18 141 2022 15 100 Remaining years 148 326 Total 243 1,826 Less: income from subleases — 71 Net minimum lease payments $ 243 1,755 Less: amount representing interest 51 Capital lease obligations $ 192 * Includes the remaining residual value deficiency on our railcar leases. See Note 13—Guarantees, for additional information. Operating lease rental expense for the years ended December 31 was: Millions of Dollars 2017 2016 2015 Minimum rentals* $ 680 669 641 Contingent rentals 6 6 6 Less: sublease rental income 73 95 136 $ 613 580 511 * Includes expenses related to the residual value deficiency on our railcar leases. See Note 13—Guarantees, for additional information.

Pension and Postretirement Plan

Pension and Postretirement Plans	12 Months Ended
	Dec. 31, 2017
Retirement Benefits [Abstract]
Pension and Postretirement Plans	Pension and Postretirement Plans The following table provides a reconciliation of the projected benefit obligations and plan assets for our pension plans and accumulated benefit obligations for our other postretirement benefit plans: Millions of Dollars Pension Benefits Other Benefits 2017 2016 2017 2016 U.S. Int’l. U.S. Int’l. Change in Benefit Obligation Benefit obligation at January 1 $ 2,881 1,055 2,791 912 225 219 Service cost 132 32 127 32 6 7 Interest cost 108 27 116 28 8 8 Plan participant contributions — 2 — 3 3 2 Actuarial loss (gain) 267 (5 ) 62 237 6 (6 ) Benefits paid (345 ) (20 ) (215 ) (19 ) (16 ) (13 ) Curtailment gain — — — (31 ) — — Acquisition of a business — — — — — 8 Foreign currency exchange rate change — 118 — (107 ) — — Benefit obligation at December 31 $ 3,043 1,209 2,881 1,055 232 225 Change in Fair Value of Plan Assets Fair value of plan assets at January 1 $ 2,274 796 2,023 742 — — Actual return on plan assets 399 71 136 148 — — Company contributions 423 35 330 40 13 11 Plan participant contributions — 2 — 3 3 2 Benefits paid (345 ) (20 ) (215 ) (19 ) (16 ) (13 ) Foreign currency exchange rate change — 88 — (118 ) — — Fair value of plan assets at December 31 $ 2,751 972 2,274 796 — — Funded Status at December 31 $ (292 ) (237 ) (607 ) (259 ) (232 ) (225 ) Amounts recognized in the consolidated balance sheet for our pension and other postretirement benefit plans at December 31, 2017 and 2016 , include: Millions of Dollars Pension Benefits Other Benefits 2017 2016 2017 2016 U.S. Int’l. U.S. Int’l. Amounts Recognized in the Consolidated Balance Sheet at December 31 Current liabilities $ (25 ) — (10 ) — (16 ) (10 ) Noncurrent liabilities (267 ) (237 ) (597 ) (259 ) (216 ) (215 ) Total recognized $ (292 ) (237 ) (607 ) (259 ) (232 ) (225 ) Included in accumulated other comprehensive income (loss) at December 31 were the following before-tax amounts that had not been recognized in net periodic benefit cost: Millions of Dollars Pension Benefits Other Benefits 2017 2016 2017 2016 U.S. Int’l. U.S. Int’l. Unrecognized net actuarial loss (gain) $ 545 190 684 227 1 (5 ) Unrecognized prior service cost (credit) — (4 ) 3 (5 ) (7 ) (9 ) Millions of Dollars Pension Benefits Other Benefits 2017 2016 2017 2016 U.S. Int’l. U.S. Int’l. Sources of Change in Other Comprehensive Income (Loss) Net gain (loss) arising during the period $ (14 ) 14 (54 ) (129 ) (6 ) 7 Curtailment gain — — — 31 — — Amortization of loss and settlements included in income 153 23 80 14 — — Net change in unrecognized net actuarial loss (gain) during the period $ 139 37 26 (84 ) (6 ) 7 Prior service cost arising during the period $ — — — — — — Amortization of prior service cost (credit) included in income 3 (1 ) 3 (1 ) (2 ) (1 ) Net change in unrecognized prior service cost (credit) during the period $ 3 (1 ) 3 (1 ) (2 ) (1 ) The accumulated benefit obligations for all U.S. and international pension plans were $2,743 million and $1,006 million , respectively, at December 31, 2017 , and $2,601 million and $880 million , respectively, at December 31, 2016 . Information for U.S. and international pension plans with an accumulated benefit obligation in excess of plan assets at December 31 were: Millions of Dollars Pension Benefits 2017 2016 U.S. Int’l. U.S. Int’l. Projected benefit obligations $ 172 389 2,881 355 Accumulated benefit obligations 143 368 2,601 334 Fair value of plan assets — 196 2,274 166 Components of net periodic benefit cost for all defined benefit plans are presented in the table below: Millions of Dollars Pension Benefits Other Benefits 2017 2016 2015 2017 2016 2015 U.S. Int’l. U.S. Int’l. U.S. Int’l. Components of Net Periodic Benefit Cost Service cost $ 132 32 127 32 124 38 6 7 7 Interest cost 108 27 116 28 109 28 8 8 7 Expected return on plan assets (146 ) (40 ) (128 ) (38 ) (138 ) (37 ) — — — Amortization of prior service cost (credit) 3 (1 ) 3 (1 ) 3 (1 ) (2 ) (1 ) (2 ) Recognized net actuarial loss (gain) 70 23 72 14 75 15 — — (1 ) Settlements 83 — 8 — 80 — — — — Total net periodic benefit cost $ 250 41 198 35 253 43 12 14 11 In determining net periodic benefit cost, we amortize prior service costs on a straight-line basis over the average remaining service period of employees expected to receive benefits under the plan. For net actuarial gains and losses, we amortize 10 percent of the unamortized balance each year. The amount subject to amortization is determined on a plan-by-plan basis. Amounts included in accumulated other comprehensive income (loss) at December 31, 2017 , that are expected to be amortized into net periodic benefit cost during 2018 are provided below: Millions of Dollars Pension Benefits Other Benefits U.S. Int’l. Unrecognized net actuarial loss $ 59 19 — Unrecognized prior service credit — (1 ) (1 ) The following weighted-average assumptions were used to determine benefit obligations and net periodic benefit costs for years ended December 31: Pension Benefits Other Benefits 2017 2016 2017 2016 U.S. Int’l. U.S. Int’l. Assumptions Used to Determine Benefit Obligations: Discount rate 3.60 % 2.36 3.95 2.42 3.35 3.65 Rate of compensation increase 4.00 3.74 4.00 3.78 — — Assumptions Used to Determine Net Periodic Benefit Cost: Discount rate 3.95 % 2.46 4.35 3.35 3.65 4.00 Expected return on plan assets 6.75 4.74 6.75 5.31 — — Rate of compensation increase 4.00 3.78 4.00 3.65 — — For both U.S. and international pension plans, the overall expected long-term rate of return is developed from the expected future return of each asset class, weighted by the expected allocation of pension assets to that asset class. We rely on a variety of independent market forecasts in developing the expected rate of return for each class of assets. Our other postretirement benefit plans for health insurance are contributory. Effective December 31, 2012, we terminated the subsidy for retiree medical plans. Since January 1, 2013, eligible employees have been able to utilize notional amounts credited to an account during their period of service with the company to pay all, or a portion, of their cost to participate in postretirement health insurance through the company. In general, employees hired after December 31, 2012, will not receive credits to an account, but will have unsubsidized access to health insurance through the plan. The cost of health insurance will be adjusted annually by the company’s actuary to reflect actual experience and expected health care cost trends. The measurement of the accumulated benefit obligation assumes a health care cost trend rate of 6.25 percent in 2018 that declines to 5.00 percent by 2023 . A one percentage-point change in the assumed health care cost trend rate would be immaterial to Phillips 66. Plan Assets The investment strategy for managing pension plan assets is to seek a reasonable rate of return relative to an appropriate level of risk and provide adequate liquidity for benefit payments and portfolio management. We follow a policy of diversifying pension plan assets across asset classes, investment managers, and individual holdings. As a result, our plan assets have no significant concentrations of credit risk. Asset classes that are considered appropriate include equities, fixed income, cash, real estate and insurance contracts. Plan fiduciaries may consider and add other asset classes to the investment program from time to time. The target allocations for plan assets are approximately 57 percent equity securities, 41 percent debt securities and 2 percent in all other types of investments. Generally, the investments in the plans are publicly traded, therefore minimizing the liquidity risk in the portfolio. The following is a description of the valuation methodologies used for the pension plan assets. • Fair values of equity securities and government debt securities are based on quoted market prices. • Fair values of mutual funds are valued based on quoted market prices, which represent the net asset value of shares held. • Cash and cash equivalents are valued at cost, which approximates fair value. • Fair values of insurance contracts are valued at the present value of the future benefit payments owed by the insurance company to the plans’ participants. • Fair values of real estate investments are valued using real estate valuation techniques and other methods that include reference to third-party sources and sales comparables where available. • Fair values of investments in common/collective trusts are valued at net asset value (NAV) as determined by the issuer of each fund. Certain investments that are measured at fair value using the NAV value per share (or its equivalent) practical expedient have not been classified in the fair value hierarchy. The fair values of our pension plan assets at December 31, by asset class, were: Millions of Dollars U.S. International Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total 2017 Equity securities $ 589 — — 589 — — — — Government debt securities 632 — — 632 — — — — Mutual funds 129 — — 129 — — — — Cash and cash equivalents 90 — — 90 6 — — 6 Insurance contracts — — — — — — 14 14 Real estate — — — — — — 8 8 Total assets in the fair value hierarchy 1,440 — — 1,440 6 — 22 28 Common/collective trusts measured at NAV 1,311 944 Total $ 1,440 — — 2,751 6 — 22 972 Millions of Dollars U.S. International Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total 2016 Equity securities $ 533 — — 533 — — — — Mutual funds 47 — — 47 — — — — Cash and cash equivalents 21 — — 21 5 — — 5 Insurance contracts — — — — — — 13 13 Real estate — — — — — — 6 6 Total assets in the fair value hierarchy 601 — — 601 5 — 19 24 Common/collective trusts measured at NAV 1,673 772 Total $ 601 — — 2,274 5 — 19 796 As reflected in the table above, Level 3 activity was not material. Our funding policy for U.S. plans is to contribute at least the minimum required by the Employee Retirement Income Security Act of 1974 and the Internal Revenue Code of 1986, as amended. Contributions to international plans are subject to local laws and tax regulations. Actual contribution amounts are dependent upon plan asset returns, changes in pension obligations, regulatory environments, and other economic factors. In 2018 , we expect to contribute approximately $60 million to our U.S. pension plans and other postretirement benefit plans and $35 million to our international pension plans. The following benefit payments, which reflect expected future service, as appropriate, are expected to be paid by us in the years indicated: Millions of Dollars Pension Benefits Other Benefits U.S. Int’l. 2018 $ 329 22 27 2019 302 22 28 2020 294 24 27 2021 290 26 26 2022 292 27 24 2023-2026 1,298 162 101 Defined Contribution Plans Most U.S. employees are eligible to participate in the Phillips 66 Savings Plan (Savings Plan). Employees can contribute up to 75 percent of their eligible pay, subject to certain statutory limits, in the thrift feature of the Savings Plan to a choice of investment funds. Phillips 66 provides a company match of participant thrift contributions up to 5 percent of eligible pay. In addition, participants who contribute at least 1 percent to the Savings Plan are eligible for “Success Share,” a semi-annual discretionary company contribution to the Savings Plan that can range from 0 to 6 percent of eligible pay, with a target of 2 percent . The total expense related to participants in the Savings Plan was $101 million , $99 million and $134 million in 2017 , 2016 and 2015 , respectively.

Share-Based Compensation Plans

Share-Based Compensation Plans	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Compensation Plans	Share-Based Compensation Plans In accordance with the Employee Matters Agreement related to the Separation, compensation awards based on ConocoPhillips stock and granted before April 30, 2012 (the Separation Date) were converted to compensation awards based on both ConocoPhillips and Phillips 66 stock if, on the Separation Date, the awards were: (1) options outstanding and exercisable; or (2) restricted stock or restricted stock units (RSUs) awarded for completed performance periods under the ConocoPhillips Performance Share Program. Phillips 66 restricted stock, RSUs and options issued in this conversion became subject to the “Omnibus Stock and Performance Incentive Plan of Phillips 66” (the 2012 Plan) on the Separation Date, whether held by grantees working for Phillips 66 or grantees that remained employees of ConocoPhillips. Some of these awards based on Phillips 66 stock and held by employees of ConocoPhillips are outstanding and appear in the activity tables for the Stock Option and the Performance Share Programs presented later in this footnote. In May 2013, shareholders approved the 2013 Omnibus Stock and Performance Incentive Plan of Phillips 66 (the P66 Omnibus Plan). Subsequent to this approval, all new share-based awards are granted under the P66 Omnibus Plan, which authorizes the Human Resources and Compensation Committee (HRCC) of our Board of Directors to grant stock options, stock appreciation rights, stock awards (including restricted stock and RSU awards), cash awards, and performance awards to our employees, non-employee directors and other plan participants. The number of new shares that may be issued under the P66 Omnibus Plan to settle share-based awards may not exceed 45 million . Total share-based compensation expense recognized in income and the associated income tax benefit for the years ended December 31 were: Millions of Dollars 2017 2016 2015 Share-based compensation expense $ 142 156 144 Income tax benefit (74 ) (59 ) (54 ) Stock Options Stock options granted under the provisions of the P66 Omnibus Plan and earlier plans permit purchases of our common stock at exercise prices equivalent to the average of the high and low market price of our stock on the date the options were granted. The options have terms of 10 years and vest ratably, with one-third of the options becoming exercisable on each anniversary date for the three years following the date of grant. Options awarded to employees eligible for retirement are not subject to forfeiture six months after the grant date. The following table summarizes our stock option activity from January 1, 2017 , to December 31, 2017 : Millions of Dollars Options Weighted- Average Exercise Price Weighted-Average Grant-Date Fair Value Aggregate Outstanding at January 1, 2017 5,103,130 $ 49.48 Granted 864,100 78.48 $ 16.95 Forfeited (32,500 ) 78.48 Exercised (1,095,875 ) 32.38 $ 62 Outstanding at December 31, 2017 4,838,855 $ 58.34 Vested at December 31, 2017 4,191,679 $ 55.25 $ 195 Exercisable at December 31, 2017 3,258,015 $ 48.79 $ 172 The weighted-average remaining contractual terms of vested options and exercisable options at December 31, 2017 , were 5.48 years and 4.62 years , respectively. During 2017 , we received $35 million in cash and realized an income tax benefit of $9 million from the exercise of options. At December 31, 2017 , the remaining unrecognized compensation expense from unvested options was $6 million , which will be recognized over a weighted-average period of 20 months, the longest period being 27 months. The calculations of realized income tax benefits and weighted-average periods include awards based on both Phillips 66 and ConocoPhillips stock held by Phillips 66 employees. During 2016 and 2015 , we granted options with a weighted-average grant-date fair value of $16.94 and $18.84 , respectively. During 2016 and 2015 , employees exercised options with an aggregate intrinsic value of $58 million and $60 million , respectively. The following table provides the significant assumptions used to calculate the grant date fair values of options granted over the years shown below, as calculated using the Black-Scholes-Merton option-pricing model: 2017 2016 2015 Risk-free interest rate 2.28 % 1.71 1.60 Dividend yield 2.90 % 3.00 3.00 Volatility factor 26.91 % 28.68 34.17 Expected life (years) 7.22 7.08 6.66 After the Separation and through 2015, we calculated the volatility of options granted using a formula that adjusts the pre-Separation historical volatility of ConocoPhillips by the ratio of Phillips 66 implied market volatility on the grant date divided by the pre-Separation implied market volatility of ConocoPhillips. In 2016, we began calculating the volatility using historical Phillips 66 end-of-week closing stock prices from the Separation date. We use the average period of time elapsed between grant dates and exercise dates of past grants to estimate the expected life of new option grants. Restricted Stock Units Generally, RSUs are granted annually under the provisions of the P66 Omnibus Plan and cliff vest at the end of three years. The grant date fair value is equal to the average of the high and low market price of our stock on the grant date. The recipients receive a quarterly cash payment of a dividend equivalent until the RSU is settled by issuing one share of our common stock for each RSU at the end of the service period. RSUs granted to retirement eligible employees are not subject to forfeiture six months after the grant date. Special RSUs are granted to attract or retain key personnel and the terms and conditions may vary by award. The following table summarizes our RSU activity from January 1, 2017 , to December 31, 2017 : Millions of Dollars Stock Units Weighted-Average Grant-Date Fair Value Total Fair Value Outstanding at January 1, 2017 2,643,139 $ 71.28 Granted 975,164 78.49 Forfeited (58,171 ) 77.18 Issued (1,063,707 ) 63.67 $ 85 Outstanding at December 31, 2017 2,496,425 $ 77.20 Not Vested at December 31, 2017 1,615,668 $ 77.32 At December 31, 2017 , the remaining unrecognized compensation cost from the unvested RSU awards was $50 million , which will be recognized over a weighted-average period of 20 months, the longest period being 37 months. During 2016 and 2015 , we granted RSUs with a weighted-average grant-date fair value of $78.56 and $74.09 , respectively. During 2016 and 2015 , we issued shares with an aggregate fair value of $109 million and $107 million , respectively, to settle RSUs. Performance Share Units Under the P66 Omnibus Plan, we annually grant to senior management restricted performance share units (PSUs) with three -year performance periods that vest: (1) with respect to awards for performance periods beginning before 2009, when the employee becomes eligible for retirement; or (2) with respect to awards for performance periods beginning in 2009, the shorter of: (a) the participant’s retirement eligibility date; or (b) five years after the grant date of the award; or (3) with respect to awards for performance periods beginning in 2013 or later, at the end of the performance period on the grant date. For PSU awards with performance periods beginning before 2013, we recognize compensation expense beginning on the date authorized and ending on the vest date. Since PSU awards with performance periods beginning in 2013 or later vest on the grant date, we recognize compensation expense beginning on the date of authorization and ending on the grant date for all employees. We settle each PSU with performance periods beginning before 2013 by issuing one share of our common stock and recipients receive a quarterly cash payment of a dividend equivalent beginning on the grant date and ending on the settlement date. PSUs with performance periods beginning in 2013 or later are settled by paying cash equal to the fair value of the awards, which is based on the average of the high and low market prices of our stock near the end of the performance periods. The HRCC must approve the three-year performance results prior to payout. Dividend equivalents are not paid on these awards. The following table summarizes our PSU activity from January 1, 2017 , to December 31, 2017 : Millions of Dollars Performance Share Units Weighted-Average Grant-Date Fair Value Total Fair Value Outstanding at January 1, 2017 3,239,497 $ 50.12 Granted 642,212 86.88 Issued (681,219 ) 42.85 $ 54 Cash settled (642,212 ) 86.88 56 Outstanding at December 31, 2017 2,558,278 $ 52.06 Not Vested at December 31, 2017 286,031 $ 66.65 At December 31, 2017 , the remaining unrecognized compensation cost from unvested PSU awards held by employees of Phillips 66 was $4 million , which will be recognized over a weighted-average period of 23 months, with the longest period being 9 years. The calculations of unamortized expense and weighted-average periods include awards based on both Phillips 66 and ConocoPhillips stock held by Phillips 66 employees. During 2016 and 2015 , we granted PSUs with a weighted-average grant-date fair value of $78.62 and $74.14 , respectively. During 2016 and 2015 , we issued shares with an aggregate fair value of $26 million and $37 million , respectively, to settle PSUs. We cash settled PSUs with an aggregate fair value of $60 million in 2016. No PSUs were cash settled in 2015.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes On December 22, 2017, the U.S. government enacted comprehensive income tax legislation, referred to as the Tax Cuts and Jobs Act (the Tax Act). The material provisions of the Tax Act i) reduced the U.S. federal corporate income tax rate from 35 percent to 21 percent beginning January 1, 2018, ii) required companies to reflect on their 2017 corporate income tax return a liability for a one-time deemed repatriation tax on foreign-sourced earnings that were previously tax deferred, and iii) created a new tax regime for post-2017 foreign-sourced earnings. To account for the reduction in the U.S. federal corporate income tax rate, we remeasured our deferred tax assets and liabilities based on the rates at which they are expected to reverse in the future, generally 21 percent , which resulted in a provisional deferred tax benefit of $2,870 million . To account for the one-time deemed repatriation income tax, we calculated our provisional liability in accordance with the Tax Act and considered previously accrued current and deferred tax liabilities on undistributed earnings of our foreign subsidiaries and foreign joint ventures. The effects of the one-time deemed repatriation tax resulted in a provisional income tax expense of $149 million . The provisions in the Tax Act are broad and complex. We have not yet completed our accounting for the income tax effects of the Tax Act as of December 31, 2017 , but have made reasonable estimates of those effects on our existing deferred income tax balances and the one-time deemed repatriation tax. The final financial statement impact of the Tax Act may differ from the above estimates, possibly materially, due to, among other things, changes in interpretations of the Tax Act, any legislative action to address questions that arise because of the Tax Act, and changes in accounting standards for income taxes or related interpretations in response to the Tax Act, or any updates or changes to estimates the company has utilized to calculate the provisional impacts. The Securities and Exchange Commission (SEC) has issued rules that would allow for a measurement period of up to one year after the enactment date of the Tax Act to finalize the recording of the related income tax impacts. Components of income tax expense (benefit) were: Millions of Dollars 2017 2016 2015 Income Tax Expense (Benefit) Federal Current $ 9 (105 ) 1,128 Deferred (1,960 ) 645 444 Foreign Current 126 66 (74 ) Deferred 3 (84 ) 42 State and local Current 61 (24 ) 227 Deferred 68 49 (3 ) $ (1,693 ) 547 1,764 Deferred income taxes reflect the net tax effect of temporary differences between the carrying amounts of assets and liabilities for financial reporting purposes and the amounts used for tax purposes. Major components of deferred tax liabilities and assets at December 31 were: Millions of Dollars 2017 2016 Deferred Tax Liabilities Properties, plants and equipment, and intangibles $ 2,942 4,525 Investment in joint ventures 1,923 2,442 Investment in subsidiaries 594 803 Inventory — 154 Other 18 19 Total deferred tax liabilities 5,477 7,943 Deferred Tax Assets Benefit plan accruals 314 669 Inventory 10 — Asset retirement obligations and accrued environmental costs 121 211 Other financial accruals and deferrals 44 188 Loss and credit carryforwards 96 261 Other 3 1 Total deferred tax assets 588 1,330 Less: valuation allowance 28 38 Net deferred tax assets 560 1,292 Net deferred tax liabilities $ 4,917 6,651 The loss and credit carryforwards deferred tax assets are primarily related to a German interest deduction carryforward of $77 million , a U.S. alternative minimum tax credit of $10 million and a capital loss and net operating loss carryforward in the United Kingdom of $7 million . All losses may be carried forward indefinitely and the alternative minimum credit of $10 million , if not utilized sooner, will become refundable with the filing of the 2021 U.S. federal income tax return. Valuation allowances have been established to reduce deferred tax assets to an amount that will, more likely than not, be realized. During 2017 , valuation allowances decreased by a total of $10 million . Based on our historical taxable income, expectations for the future and available tax planning strategies, management expects the remaining net deferred tax assets will be realized as offsets to reversing deferred tax liabilities and the tax consequences of future taxable income. At December 31, 2017 , all undistributed earnings of our foreign subsidiaries and foreign joint ventures have been included in our provisional computation of the one-time deemed repatriation tax associated with the enactment of the Tax Act. After considering the effects of the Tax Act described above, we have not provided a deferred tax liability related to any remaining difference in the book and tax investment in our foreign subsidiaries or foreign joint ventures because such differences are essentially permanent in duration. Based on our preliminary analysis, which is not yet complete, the temporary difference and associated unrecorded deferred tax liability are not material. As a result of the Separation and pursuant to the Tax Sharing Agreement with ConocoPhillips, the unrecognized income tax benefits related to our operations for which ConocoPhillips was the taxpayer remain the responsibility of ConocoPhillips, and we have indemnified ConocoPhillips for such amounts. Following is a reconciliation of the changes in our unrecognized income tax benefits balance: Millions of Dollars 2017 2016 2015 Balance at January 1 $ 70 82 142 Additions for tax positions of prior years 1 5 6 Reductions for tax positions of prior years (5 ) (17 ) (17 ) Settlements (32 ) — (49 ) Balance at December 31 $ 34 70 82 Included in the balance of unrecognized income tax benefits for 2017 , 2016 and 2015 were $5 million , $13 million and $34 million , respectively, which, if recognized, would affect our effective income tax rate. With respect to various unrecognized income tax benefits and the related accrued liability, approximately $2 million may be recognized or paid within the next twelve months due to completion of audits. At December 31, 2017 , 2016 and 2015 , accrued liabilities for interest and penalties, net of accrued income taxes, totaled $8 million , $12 million and $19 million , respectively. As a result of reversing certain of these accruals, earnings increased by $1 million , $7 million and $3 million in 2017 , 2016 and 2015 , respectively. We file tax returns in the U.S. federal jurisdiction and in many foreign and state jurisdictions. Audits in significant jurisdictions are generally complete as follows: United Kingdom (2014), Germany (2011) and United States (2010). Certain issues remain in dispute for audited years, and unrecognized income tax benefits for years still subject to or currently undergoing an audit are subject to change. As a consequence, the balance in unrecognized income tax benefits can be expected to fluctuate from period to period. Although it is reasonably possible such changes could be significant when compared with our total unrecognized income tax benefits, the amount of change is not estimable. The amounts of U.S. and foreign income before income taxes, with a reconciliation of income tax at the federal statutory rate to the recorded income tax expense (benefit), were: Millions of Dollars Percentage of Income Before Income Taxes 2017 2016 2015 2017 2016 2015 Income before income taxes United States $ 2,799 1,713 4,983 78.7 % 78.2 82.4 Foreign 756 478 1,061 21.3 21.8 17.6 $ 3,555 2,191 6,044 100.0 % 100.0 100.0 Federal statutory income tax $ 1,244 767 2,115 35.0 % 35.0 35.0 State income tax, net of federal benefit 79 12 150 2.2 0.6 2.5 Tax Cuts and Jobs Act (2,721 ) — — (76.5 ) — — Foreign rate differential (210 ) (152 ) (239 ) (5.9 ) (6.9 ) (3.9 ) Noncontrolling interests (46 ) (26 ) (13 ) (1.3 ) (1.2 ) (0.2 ) Federal manufacturing deduction (18 ) — (77 ) (0.5 ) — (1.3 ) Change in valuation allowance (4 ) (81 ) (17 ) (0.1 ) (3.7 ) (0.2 ) Goodwill allocated to assets sold — — 41 — — 0.7 German tax legislation — — (103 ) — — (1.7 ) Sale of foreign subsidiaries — — (125 ) — — (2.1 ) Other (17 ) 27 32 (0.5 ) 1.2 0.4 $ (1,693 ) 547 1,764 (47.6 )% 25.0 29.2 Included in the line item “Sale of foreign subsidiaries” is a $72 million income tax benefit realized in 2015 attributable to the nontaxable gain from the sale of ICHP. Income tax expense of $81 million and $150 million in 2017 and 2016 , respectively, and an income tax benefit of $34 million in 2015 are reflected in the “Capital in Excess of Par” column on our consolidated statement of changes in equity.

Accumulated Other Comprehensive

Accumulated Other Comprehensive Income (Loss)	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Accumulated Other Comprehensive Income (Loss)	Accumulated Other Comprehensive Income (Loss) Changes in the balances of each component of accumulated other comprehensive income (loss) were as follows: Millions of Dollars Defined Benefit Plans Foreign Currency Translation Hedging Accumulated Other Comprehensive Loss December 31, 2014 $ (696 ) 167 (2 ) (531 ) Other comprehensive loss before reclassification (78 ) (156 ) — (234 ) Amounts reclassified from accumulated other comprehensive loss* Amortization of defined benefit plan items** Actuarial losses and settlements 112 — — 112 Net current period other comprehensive income (loss) 34 (156 ) — (122 ) December 31, 2015 (662 ) 11 (2 ) (653 ) Other comprehensive income (loss) before reclassifications (112 ) (296 ) 5 (403 ) Amounts reclassified from accumulated other comprehensive loss* Amortization of defined benefit plan items** Actuarial losses and settlements 61 — — 61 Net current period other comprehensive income (loss) (51 ) (296 ) 5 (342 ) December 31, 2016 (713 ) (285 ) 3 (995 ) Other comprehensive income before reclassifications 3 259 4 266 Amounts reclassified from accumulated other comprehensive loss* Amortization of defined benefit plan items** Actuarial losses and settlements 112 — — 112 Net current period other comprehensive income 115 259 4 378 December 31, 2017 $ (598 ) (26 ) 7 (617 ) * There were no significant reclassifications related to foreign currency translation or hedging. ** Included in the computation of net periodic benefit cost. See Note 19—Pension and Postretirement Plans , for additional information.

Cash Flow Information

Cash Flow Information	12 Months Ended
	Dec. 31, 2017
Supplemental Cash Flow Information [Abstract]
Cash Flow Information	Cash Flow Information Supplemental Cash Flow Information Millions of Dollars 2017 2016 2015 Cash Payments (Receipts) Interest $ 421 311 275 Income taxes* (257 ) (375 ) 1,560 * 2017 and 2016 reflected a net cash refund position; cash payments for income taxes were $102 million and $385 million in 2017 and 2016, respectively. Restricted Cash At December 31, 2017 and 2016, the company did not have any restricted cash. The restrictions on the cash acquired in February 2017, as a result of the consolidation of MSLP, were fully removed in May 2017 when MSLP’s outstanding debt that contained lender restrictions on the use of cash was paid in full. See Note 5—Business Combinations and Note 12—Debt for additional information regarding MSLP.

Other Financial Information

Other Financial Information	12 Months Ended
	Dec. 31, 2017
Other Income and Expenses [Abstract]
Other Financial Information	Other Financial Information Millions of Dollars 2017 2016 2015 Interest and Debt Expense Incurred Debt $ 432 402 389 Other 21 17 27 453 419 416 Capitalized (15 ) (81 ) (106 ) Expensed $ 438 338 310 Other Income Interest income $ 31 18 27 Gain on consolidation of business* 423 — — Other, net** 67 56 91 $ 521 74 118 * See Note 5—Business Combinations regarding the gain recognized in 2017. ** Includes derivatives-related activities. Research and Development Expenditures— expensed $ 60 60 65 Advertising Expenses $ 76 80 73 Foreign Currency Transaction (Gains) Losses— after-tax Midstream $ — — — Chemicals — — — Refining (1 ) (10 ) 34 Marketing and Specialties 1 1 4 Corporate and Other — (2 ) — $ — (11 ) 38

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2017
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions Significant transactions with related parties were: Millions of Dollars 2017 2016 2015 Operating revenues and other income (a) $ 2,596 2,174 2,452 Purchases (b) 10,468 8,109 8,142 Operating expenses and selling, general and administrative expenses (c) 79 125 129 As discussed more fully in Note 5—Business Combinations , in February 2017, we began accounting for MSLP as a consolidated subsidiary. Accordingly, the table above only includes processing fees paid to MSLP through the consolidation date. (a) We sold NGL and other petrochemical feedstocks, along with solvents, to CPChem, and we sold gas oil and hydrogen feedstocks to Excel Paralubes (Excel). We sold refined products to our OnCue Holdings, LLC joint venture. We sold certain feedstocks and intermediate products to WRB and also acted as agent for WRB in supplying crude oil and other feedstocks for a fee. In addition, we charged several of our affiliates, including CPChem, for the use of common facilities, such as steam generators, waste and water treaters, and warehouse facilities. (b) We purchased crude oil and refined products from WRB and also acted as agent for WRB in distributing solvents. We purchased natural gas and NGL from DCP Midstream and CPChem, as well as other feedstocks from various affiliates, for use in our refinery and fractionation processes. We paid NGL fractionation fees to CPChem. We also paid fees to various pipeline equity companies for transporting crude oil, refined products and NGL. We purchased base oils and fuel products from Excel for use in our refining and specialty businesses. (c) We paid utility and processing fees to various affiliates.

Segment Disclosures and Related

Segment Disclosures and Related Information	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Segment Disclosures and Related Information	Segment Disclosures and Related Information Our operating segments are: 1) Midstream— Provides crude oil and refined products transportation, terminaling and processing services, as well as natural gas, NGL and liquefied petroleum gas (LPG) transportation, storage, processing and marketing services, mainly in the United States. The Midstream segment includes our master limited partnership, Phillips 66 Partners, as well as our 50 percent equity investment in DCP Midstream. 2) Chemicals— Consists of our 50 percent equity investment in CPChem, which manufactures and markets petrochemicals and plastics on a worldwide basis. 3) Refining— Refines crude oil and other feedstocks into petroleum products (such as gasoline, distillates and aviation fuels) at 13 refineries in the United States and Europe. 4) Marketing and Specialties— Purchases for resale and markets refined petroleum products, mainly in the United States and Europe. In addition, this segment includes the manufacturing and marketing of specialty products, as well as power generation operations. Corporate and Other includes general corporate overhead, interest expense, our investments in new technologies and various other corporate activities. Corporate assets include all cash and cash equivalents. In addition, Corporate and Other includes the provisional income tax benefit from the enactment of the Tax Act on December 22, 2017. See Note 21— Income Taxes for further discussion. During the fourth quarter of 2017, the segment performance measure used by our chief executive officer to assess performance and allocate resources was changed from “net income attributable to Phillips 66” to “net income.” This change reflects the recognition that management does not differentiate between those earnings attributable to Phillips 66 and those attributable to noncontrolling interests when making operating and resource allocation decisions impacting segment performance. Prior period segment information has been recast to conform to the current presentation. Intersegment sales are at prices that we believe approximate market. Analysis of Results by Operating Segment Millions of Dollars 2017 2016 2015 Sales and Other Operating Revenues Midstream Total sales $ 6,620 4,226 3,676 Intersegment eliminations (1,842 ) (1,299 ) (1,034 ) Total Midstream 4,778 2,927 2,642 Chemicals 5 5 5 Refining Total sales 65,494 52,068 63,470 Intersegment eliminations (40,284 ) (34,120 ) (40,317 ) Total Refining 25,210 17,948 23,153 Marketing and Specialties Total sales 73,565 64,476 74,591 Intersegment eliminations (1,233 ) (1,109 ) (1,446 ) Total Marketing and Specialties 72,332 63,367 73,145 Corporate and Other 29 32 30 Consolidated sales and other operating revenues $ 102,354 84,279 98,975 Depreciation, Amortization and Impairments Midstream $ 299 218 128 Chemicals — — — Refining 838 770 741 Marketing and Specialties 116 107 100 Corporate and Other 89 78 116 Consolidated depreciation, amortization and impairments $ 1,342 1,173 1,085 Millions of Dollars 2017 2016 2015 Equity in Earnings of Affiliates Midstream $ 454 184 (268 ) Chemicals 713 834 1,316 Refining 322 164 325 Marketing and Specialties 243 232 207 Corporate and Other — — (7 ) Consolidated equity in earnings of affiliates $ 1,732 1,414 1,573 Income Tax Expense (Benefit) Midstream $ 174 123 73 Chemicals 191 256 353 Refining 672 61 1,104 Marketing and Specialties 334 370 466 Corporate and Other (3,064 ) (263 ) (232 ) Consolidated income tax expense (benefit) $ (1,693 ) 547 1,764 Net Income (Loss) Midstream $ 464 280 74 Chemicals 525 583 962 Refining 1,404 374 2,555 Marketing and Specialties 686 891 1,187 Corporate and Other 2,169 (484 ) (498 ) Consolidated net income $ 5,248 1,644 4,280 Millions of Dollars 2017 2016 2015 Investments In and Advances To Affiliates Midstream $ 4,734 4,769 4,198 Chemicals 6,222 5,773 5,177 Refining 2,398 2,420 2,262 Marketing and Specialties 390 391 342 Corporate and Other — 1 1 Consolidated investments in and advances to affiliates $ 13,744 13,354 11,980 Total Assets Midstream $ 13,231 12,832 11,043 Chemicals 6,226 5,802 5,237 Refining 23,820 22,825 21,993 Marketing and Specialties 7,103 6,227 5,631 Corporate and Other 3,991 3,967 4,676 Consolidated total assets $ 54,371 51,653 48,580 Capital Expenditures and Investments Midstream $ 771 1,453 4,457 Chemicals — — — Refining 853 1,149 1,069 Marketing and Specialties 108 98 122 Corporate and Other 100 144 116 Consolidated capital expenditures and investments $ 1,832 2,844 5,764 Interest Income and Expense Interest income Midstream $ 1 2 — Marketing and Specialties — — 2 Corporate and Other 30 16 25 Consolidated interest income $ 31 18 27 Interest and debt expense Corporate and Other $ 438 338 310 Sales and Other Operating Revenues by Product Line Refined products $ 85,405 73,385 86,249 Crude oil resales 11,808 7,594 8,993 NGL 4,670 3,107 2,998 Other 471 193 735 Consolidated sales and other operating revenues by product line $ 102,354 84,279 98,975 Geographic Information Millions of Dollars Sales and Other Operating Revenues* Long-Lived Assets** 2017 2016 2015 2017 2016 2015 United States $ 75,684 59,742 69,578 33,264 32,442 29,624 United Kingdom 10,626 9,895 12,120 1,254 1,177 1,459 Germany 6,692 6,128 6,584 591 503 502 Other foreign countries 9,352 8,514 10,693 95 87 116 Worldwide consolidated $ 102,354 84,279 98,975 35,204 34,209 31,701 * Sales and other operating revenues are attributable to countries based on the location of the operations generating the revenues. ** Defined as net properties, plants and equipment plus investments in and advances to affiliated companies.

Phillips 66 Partners LP

Phillips 66 Partners LP	12 Months Ended
	Dec. 31, 2017
Limited Liability Company or Limited Partnership, Business Organization and Operations [Abstract]
Phillips 66 Partners LP	Phillips 66 Partners LP Phillips 66 Partners is a publicly traded master limited partnership formed to own, operate, develop and acquire primarily fee-based crude oil, refined petroleum product and NGL pipelines and terminals, as well as other midstream assets. Headquartered in Houston, Texas, Phillips 66 Partners’ assets currently consist of crude oil, refined petroleum products and NGL transportation, terminaling and storage systems, as well as crude oil and NGL processing facilities. We consolidate Phillips 66 Partners as a variable interest entity for financial reporting purposes. See Note 3—Variable Interest Entities for additional information on why we consolidate the partnership. As a result of this consolidation, the public common and perpetual convertible preferred unitholders’ ownership interests in Phillips 66 Partners are reflected as noncontrolling interests of $2,314 million and $1,306 million on our consolidated balance sheet as of December 31, 2017, and 2016, respectively. Generally, drop down transactions to Phillips 66 Partners will eliminate in consolidation, except for third-party debt and third-party equity offerings made by Phillips 66 Partners to finance such transactions. At December 31, 2017, we owned a 55 percent limited partner interest and a 2 percent general partner interest in Phillips 66 Partners, while the public owned a 43 percent limited partner interest and 13.8 million perpetual convertible preferred units. 2017 Activities In October 2017, we contributed to Phillips 66 Partners our 25 percent interests in both Dakota Access and ETCO and our 100 percent interest in MSLP. Total consideration for the transaction was $1.65 billion , which consisted of $372 million in cash at closing, the assumption of $588 million of promissory notes payable to us, the assumption of a $450 million term loan payable to a third party, and the issuance to us of common and general partner units with a fair value of $240 million . Shortly after closing, Phillips 66 Partners repaid the $588 million of promissory notes payable to us, resulting in total cash received by us for the transaction of $960 million . Phillips 66 Partners financed the consideration paid with the proceeds from the following third-party equity and debt offerings: • Net proceeds of $737 million from a private placement of 13,819,791 perpetual convertible preferred units, at a price of $54.27 per unit. Holders of the preferred units are entitled to receive cumulative quarterly distributions equal to $0.678375 per unit. Beginning in October 2020, holders are entitled to receive quarterly distributions equal to the greater of $0.678375 per unit or the per-unit distribution paid to common unitholders. • Net proceeds of $295 million from a private placement of 6,304,204 common units, at a price of $47.59 per unit. • A portion of the $643 million of net proceeds from a public offering of $650 million of Senior Notes. See Note 12— Debt for additional information on the Senior Notes. In June 2016, Phillips 66 Partners began issuing common units under a continuous offering program, which allows for the issuance of up to an aggregate of $250 million of Phillips 66 Partners’ common units, in amounts, at prices and on terms to be determined by market conditions and other factors at the time of the offerings (such continuous offering program, or at-the-market program, is referred to as the ATM program). For year ended December 31, 2017, on a settlement-date basis, Phillips 66 Partners issued 3,372,716 common units under the ATM program, which generated net proceeds of $173 million . From inception through December 31, 2017, Phillips 66 Partners has issued an aggregate of 3,718,868 common units under the ATM program, which generated net proceeds of $192 million . Phillips 66 Partners filed a new shelf registration statement for Phillips 66 Partners ’ second continuous offering program that became effective with the SEC on January 23, 2018, which allows for the issuance of up to an aggregate of $250 million of Phillips 66 Partners’ common units, in amounts, at prices and on terms to be determined by market conditions and other factors at the time of the offerings .

New Accounting Standards

New Accounting Standards	12 Months Ended
	Dec. 31, 2017
New Accounting Standards [Abstract]
New Accounting Standards	New Accounting Standards In February 2017, the FASB issued ASU No. 2017-05, “Other Income—Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20).” This ASU clarifies the scope and accounting for the sale or transfer of nonfinancial assets and in substance nonfinancial assets to noncustomers, including partial sales. This ASU will eliminate the use of carryover basis for most nonmonetary exchanges, including contributions of assets to equity method joint ventures. These amendments could result in the entity recognizing a gain or loss on the sale or transfer of nonfinancial assets. Public entities should apply the guidance in ASU No. 2017-05 to annual periods beginning after December 15, 2017, including interim periods within those periods. There was no impact on our financial statements from adopting this ASU on January 1, 2018. In January 2017, the FASB issued ASU No. 2017-01, “Business Combinations (Topic 805): Clarifying the Definition of a Business,” which clarifies the definition of a business with the objective of adding guidance to assist in evaluating whether transactions should be accounted for as acquisitions of assets or businesses. The amendment provides a screen for determining when a transaction involves an acquisition of a business. If substantially all of the fair value of the gross assets acquired is concentrated in a single identifiable asset, or a group of similar identifiable assets, then the transaction is not considered an acquisition of a business. If the screen is not met, then the amendment requires that to be considered a business, the operation must include at a minimum an input and a substantive process that together significantly contribute to the ability to create an output. The guidance may reduce the number of transactions accounted for as business acquisitions. Public business entities should apply the guidance in ASU No. 2017-01 to annual periods beginning after December 15, 2017, including interim periods within those periods, with early adoption permitted. The amendments should be applied prospectively and no disclosures are required at the effective date. There was no impact on our financial statements from adopting this ASU on January 1, 2018. In June 2016, the FASB issued ASU No. 2016-13, “Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments.” The new standard amends the impairment model to utilize an expected loss methodology in place of the currently used incurred loss methodology, which may result in earlier recognition of losses. Public business entities should apply the guidance in ASU No. 2016-13 for annual periods beginning after December 15, 2019, including interim periods within those annual periods. Early adoption will be permitted for annual periods beginning after December 15, 2018. We are currently evaluating the provisions of ASU No. 2016-13 and assessing the impact on our financial statements. In February 2016, the FASB issued ASU No. 2016-02, “Leases (Topic 842).” The new standard establishes a right-of-use (ROU) model that requires a lessee to record a ROU asset and a lease liability on the balance sheet for all leases with terms longer than 12 months. Leases will continue to be classified as either finance or operating, with classification affecting the pattern of expense recognition in the income statement. Similarly, lessors will be required to classify leases as sales-type, finance or operating, with classification affecting the pattern of income recognition. Classification for both lessees and lessors will be based on an assessment of whether risks and rewards as well as substantive control have been transferred through a lease contract. Public business entities should apply the guidance in ASU No. 2016-02 for annual periods beginning after December 15, 2018, including interim periods within those annual periods. Early adoption is permitted. Entities are required to adopt the ASU using a modified retrospective approach, subject to certain optional practical expedients, and apply the provisions of ASU No. 2016-02 to leasing arrangements existing at or entered into after the earliest comparative period presented in the financial statements. We are currently evaluating the provisions of ASU No. 2016-02 and assessing its impact on our financial statements. As part of our assessment to-date, we have formed an implementation team, commenced identification of our lease population and selected a lease software package. We expect the adoption of ASU 2016-02 will materially gross up our consolidated balance sheet with the recognition of the ROU assets and operating lease liabilities. The impact to our consolidated statements of income and cash flows is not expected to be material. The new standard will also require additional disclosures for financing and operating leases. In January 2016, the FASB issued ASU No. 2016-01, “Financial Instruments—Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities,” to meet its objective of providing more decision-useful information about financial instruments. The majority of this ASU’s provisions amend only the presentation or disclosures of financial instruments; however, one provision will also affect net income. Equity investments carried under the cost method or lower of cost or fair value method of accounting, in accordance with current GAAP, will have to be carried at fair value upon adoption of ASU No. 2016-01, with changes in fair value recorded in net income. For equity investments that do not have readily determinable fair values, a company may elect to carry such investments at cost less impairments, if any, adjusted up or down for price changes in similar financial instruments issued by the investee, when and if observed. Public business entities should apply the guidance in ASU No. 2016-01 for annual periods beginning after December 15, 2017, and interim periods within those annual periods, with early adoption prohibited. We are currently evaluating the provisions of ASU No. 2016-01. Our initial review indicates that ASU No. 2016-01 will have a limited impact on our financial statements. In May 2014, the FASB issued ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606).” This ASU and other related updates are intended to improve comparability of revenue recognition practices across entities, industries, jurisdictions and capital markets and expand disclosure requirements. In August 2015, the FASB issued ASU No. 2015-14, “Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date.” The amendment in this ASU defers the effective date of ASU No. 2014-09 for all entities for one year. Public business entities should apply the guidance in ASU No. 2014-09 to annual reporting periods beginning after December 15, 2017, including interim reporting periods within that reporting period. Our assessment work primarily included the formation of an implementation work team, training on the new ASU’s revenue recognition model, contract review and documentation and the monitoring of industry interpretative issues. We adopted the standard on January 1, 2018, using the modified retrospective application. Our evaluation of the new ASU is near completion, which includes understanding the impact of adoption on earnings from equity method investments. Based upon our analysis to-date, the primary impact of adoption of the new standard is the netting of sales-based taxes collected from our customers against revenue. Sales-based taxes include excise taxes on sales of petroleum products as noted on our consolidated statement of income. We have not identified any other material impact on our financial statements other than disclosures.

Condensed Consolidating Financi

Condensed Consolidating Financial Information	12 Months Ended
	Dec. 31, 2017
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Condensed Consolidating Financial Information	Condensed Consolidating Financial Information Phillips 66 has $6.0 billion of senior notes outstanding, the payment obligations of which are fully and unconditionally guaranteed by Phillips 66 Company, a 100 -percent-owned subsidiary. The following condensed consolidating financial information presents the results of operations, financial position and cash flows for: • Phillips 66 and Phillips 66 Company (in each case, reflecting investments in subsidiaries utilizing the equity method of accounting). • All other nonguarantor subsidiaries. • The consolidating adjustments necessary to present Phillips 66’s results on a consolidated basis. This condensed consolidating financial information should be read in conjunction with the accompanying consolidated financial statements and notes. Millions of Dollars Year Ended December 31, 2017 Statement of Income Phillips 66 Phillips 66 Company All Other Subsidiaries Consolidating Adjustments Total Consolidated Revenues and Other Income Sales and other operating revenues $ — 74,640 27,714 — 102,354 Equity in earnings of affiliates 5,336 3,256 559 (7,419 ) 1,732 Net gain on dispositions — 1 14 — 15 Other income 3 471 47 — 521 Intercompany revenues — 1,610 13,457 (15,067 ) — Total Revenues and Other Income 5,339 79,978 41,791 (22,486 ) 104,622 Costs and Expenses Purchased crude oil and products — 63,812 30,379 (14,782 ) 79,409 Operating expenses — 3,672 1,085 (58 ) 4,699 Selling, general and administrative expenses 7 1,300 399 (11 ) 1,695 Depreciation and amortization — 892 426 — 1,318 Impairments — 20 4 — 24 Taxes other than income taxes — 5,784 7,678 — 13,462 Accretion on discounted liabilities — 17 5 — 22 Interest and debt expense 348 70 236 (216 ) 438 Total Costs and Expenses 355 75,567 40,212 (15,067 ) 101,067 Income before income taxes 4,984 4,411 1,579 (7,419 ) 3,555 Income tax benefit (122 ) (925 ) (646 ) — (1,693 ) Net Income 5,106 5,336 2,225 (7,419 ) 5,248 Less: net income attributable to noncontrolling interests — — 142 — 142 Net Income Attributable to Phillips 66 $ 5,106 5,336 2,083 (7,419 ) 5,106 Comprehensive Income $ 5,484 5,714 2,498 (8,070 ) 5,626 Millions of Dollars Year Ended December 31, 2016 Statement of Income Phillips 66 Phillips 66 Company All Other Subsidiaries Consolidating Adjustments Total Consolidated Revenues and Other Income Sales and other operating revenues $ — 58,822 25,457 — 84,279 Equity in earnings of affiliates 1,797 1,839 296 (2,518 ) 1,414 Net gain (loss) on dispositions — (9 ) 19 — 10 Other income — 42 32 — 74 Intercompany revenues — 864 9,160 (10,024 ) — Total Revenues and Other Income 1,797 61,558 34,964 (12,542 ) 85,777 Costs and Expenses Purchased crude oil and products — 48,171 24,102 (9,805 ) 62,468 Operating expenses — 3,465 846 (36 ) 4,275 Selling, general and administrative expenses 6 1,236 406 (10 ) 1,638 Depreciation and amortization — 821 347 — 1,168 Impairments — 1 4 — 5 Taxes other than income taxes — 5,477 8,211 — 13,688 Accretion on discounted liabilities — 16 5 — 21 Interest and debt expense 366 21 124 (173 ) 338 Foreign currency transaction gains — — (15 ) — (15 ) Total Costs and Expenses 372 59,208 34,030 (10,024 ) 83,586 Income before income taxes 1,425 2,350 934 (2,518 ) 2,191 Income tax expense (benefit) (130 ) 553 124 — 547 Net Income 1,555 1,797 810 (2,518 ) 1,644 Less: net income attributable to noncontrolling interests — — 89 — 89 Net Income Attributable to Phillips 66 $ 1,555 1,797 721 (2,518 ) 1,555 Comprehensive Income $ 1,213 1,455 451 (1,817 ) 1,302 Millions of Dollars Year Ended December 31, 2015 Statement of Income Phillips 66 Phillips 66 Company All Other Subsidiaries Consolidating Adjustments Total Consolidated Revenues and Other Income Sales and other operating revenues $ — 68,478 30,497 — 98,975 Equity in earnings (losses) of affiliates 4,470 2,812 (134 ) (5,575 ) 1,573 Net gain (loss) on dispositions — (115 ) 398 — 283 Other income — 81 37 — 118 Intercompany revenues — 1,071 9,845 (10,916 ) — Total Revenues and Other Income 4,470 72,327 40,643 (16,491 ) 100,949 Costs and Expenses Purchased crude oil and products — 54,925 29,221 (10,747 ) 73,399 Operating expenses 4 3,412 917 (39 ) 4,294 Selling, general and administrative expenses 5 1,265 416 (16 ) 1,670 Depreciation and amortization — 818 260 — 1,078 Impairments — 4 3 — 7 Taxes other than income taxes — 5,505 8,572 — 14,077 Accretion on discounted liabilities — 16 5 — 21 Interest and debt expense 365 25 34 (114 ) 310 Foreign currency transaction losses — 1 48 — 49 Total Costs and Expenses 374 65,971 39,476 (10,916 ) 94,905 Income before income taxes 4,096 6,356 1,167 (5,575 ) 6,044 Income tax expense (benefit) (131 ) 1,886 9 — 1,764 Net Income 4,227 4,470 1,158 (5,575 ) 4,280 Less: net income attributable to noncontrolling interests — — 53 — 53 Net Income Attributable to Phillips 66 $ 4,227 4,470 1,105 (5,575 ) 4,227 Comprehensive Income $ 4,105 4,348 1,032 (5,327 ) 4,158 Millions of Dollars At December 31, 2017 Balance Sheet Phillips 66 Phillips 66 Company All Other Subsidiaries Consolidating Adjustments Total Consolidated Assets Cash and cash equivalents $ — 1,411 1,708 — 3,119 Accounts and notes receivable 10 5,317 4,476 (2,297 ) 7,506 Inventories — 2,386 1,009 — 3,395 Prepaid expenses and other current assets 2 276 92 — 370 Total Current Assets 12 9,390 7,285 (2,297 ) 14,390 Investments and long-term receivables 32,125 23,483 9,959 (51,626 ) 13,941 Net properties, plants and equipment — 13,117 8,343 — 21,460 Goodwill — 2,853 417 — 3,270 Intangibles — 722 154 — 876 Other assets 12 266 158 (2 ) 434 Total Assets $ 32,149 49,831 26,316 (53,925 ) 54,371 Liabilities and Equity Accounts payable $ — 7,272 3,052 (2,297 ) 8,027 Short-term debt — 9 32 — 41 Accrued income and other taxes — 451 551 — 1,002 Employee benefit obligations — 513 69 — 582 Other accruals 55 298 102 — 455 Total Current Liabilities 55 8,543 3,806 (2,297 ) 10,107 Long-term debt 6,972 50 3,047 — 10,069 Asset retirement obligations and accrued environmental costs — 467 174 — 641 Deferred income taxes — 3,349 1,661 (2 ) 5,008 Employee benefit obligations — 639 245 — 884 Other liabilities and deferred credits 8 4,700 3,814 (8,288 ) 234 Total Liabilities 7,035 17,748 12,747 (10,587 ) 26,943 Common stock 9,396 24,952 10,125 (35,077 ) 9,396 Retained earnings 16,335 7,748 1,306 (9,083 ) 16,306 Accumulated other comprehensive loss (617 ) (617 ) (205 ) 822 (617 ) Noncontrolling interests — — 2,343 — 2,343 Total Liabilities and Equity $ 32,149 49,831 26,316 (53,925 ) 54,371 Millions of Dollars At December 31, 2016 Balance Sheet Phillips 66 Phillips 66 Company All Other Subsidiaries Consolidating Adjustments Total Consolidated Assets Cash and cash equivalents $ — 854 1,857 — 2,711 Accounts and notes receivable 13 4,336 3,276 (1,228 ) 6,397 Inventories — 2,198 952 — 3,150 Prepaid expenses and other current assets 2 317 103 — 422 Total Current Assets 15 7,705 6,188 (1,228 ) 12,680 Investments and long-term receivables 31,165 22,733 8,588 (48,952 ) 13,534 Net properties, plants and equipment — 13,044 7,811 — 20,855 Goodwill — 2,853 417 — 3,270 Intangibles — 719 169 — 888 Other assets 15 245 168 (2 ) 426 Total Assets $ 31,195 47,299 23,341 (50,182 ) 51,653 Liabilities and Equity Accounts payable $ — 5,626 2,663 (1,228 ) 7,061 Short-term debt 500 30 20 — 550 Accrued income and other taxes — 348 457 — 805 Employee benefit obligations — 475 52 — 527 Other accruals 59 371 90 — 520 Total Current Liabilities 559 6,850 3,282 (1,228 ) 9,463 Long-term debt 6,920 150 2,518 — 9,588 Asset retirement obligations and accrued environmental costs — 501 154 — 655 Deferred income taxes — 4,391 2,354 (2 ) 6,743 Employee benefit obligations — 948 268 — 1,216 Other liabilities and deferred credits 1,297 3,337 4,060 (8,431 ) 263 Total Liabilities 8,776 16,177 12,636 (9,661 ) 27,928 Common stock 10,777 25,403 10,117 (35,520 ) 10,777 Retained earnings 12,637 6,714 (269 ) (6,474 ) 12,608 Accumulated other comprehensive loss (995 ) (995 ) (478 ) 1,473 (995 ) Noncontrolling interests — — 1,335 — 1,335 Total Liabilities and Equity $ 31,195 47,299 23,341 (50,182 ) 51,653 Millions of Dollars Year Ended December 31, 2017 Statement of Cash Flows Phillips 66 Phillips 66 Company All Other Subsidiaries Consolidating Adjustments Total Consolidated Cash Flows From Operating Activities Net Cash Provided by Operating Activities $ 2,619 2,702 1,747 (3,420 ) 3,648 Cash Flows From Investing Activities Capital expenditures and investments* — (1,133 ) (839 ) 140 (1,832 ) Proceeds from asset dispositions** — 265 84 (263 ) 86 Intercompany lending activities 401 1,453 (1,854 ) — — Advances/loans—related parties — (10 ) — — (10 ) Collection of advances/loans—related parties — 75 251 — 326 Restricted cash received from consolidation of business — — 318 — 318 Other — (26 ) (8 ) — (34 ) Net Cash Provided by (Used in) Investing Activities 401 624 (2,048 ) (123 ) (1,146 ) Cash Flows From Financing Activities Issuance of debt 1,500 — 2,008 — 3,508 Repayment of debt (1,500 ) (17 ) (2,161 ) — (3,678 ) Issuance of common stock 35 — — — 35 Repurchase of common stock (1,590 ) — — — (1,590 ) Dividends paid on common stock (1,395 ) (2,752 ) (668 ) 3,420 (1,395 ) Distributions to noncontrolling interests — — (120 ) — (120 ) Net proceeds from issuance of Phillips 66 Partners LP common and preferred units — — 1,205 — 1,205 Other* (70 ) — (129 ) 123 (76 ) Net Cash Provided by (Used in) Financing Activities (3,020 ) (2,769 ) 135 3,543 (2,111 ) Effect of Exchange Rate Changes on Cash, Cash Equivalents and Restricted Cash — — 17 — 17 Net Change in Cash, Cash Equivalents and Restricted Cash — 557 (149 ) — 408 Cash, cash equivalents and restricted cash at beginning of period — 854 1,857 — 2,711 Cash, Cash Equivalents and Restricted Cash at End of Period $ — 1,411 1,708 — 3,119 * Includes intercompany capital contributions. ** Includes return of investments in equity affiliates. Millions of Dollars Year Ended December 31, 2016 Statement of Cash Flows Phillips 66 Phillips 66 Company All Other Subsidiaries* Consolidating Adjustments Total Consolidated Cash Flows From Operating Activities Net Cash Provided by Operating Activities $ 3,491 2,307 1,552 (4,387 ) 2,963 Cash Flows From Investing Activities Capital expenditures and investments** — (1,425 ) (1,457 ) 38 (2,844 ) Proceeds from asset dispositions*** — 1,007 156 (1,007 ) 156 Intercompany lending activities (1,139 ) 2,046 (907 ) — — Advances/loans—related parties — (75 ) (357 ) — (432 ) Collection of advances/loans—related parties — — 108 — 108 Other — 18 (164 ) — (146 ) Net Cash Provided by (Used in) Investing Activities (1,139 ) 1,571 (2,621 ) (969 ) (3,158 ) Cash Flows From Financing Activities Issuance of debt — — 2,090 — 2,090 Repayment of debt — (26 ) (807 ) — (833 ) Issuance of common stock 34 — — — 34 Repurchase of common stock (1,042 ) — — — (1,042 ) Dividends paid on common stock (1,282 ) (3,604 ) (783 ) 4,387 (1,282 ) Distributions to noncontrolling interests — — (75 ) — (75 ) Net proceeds from issuance of Phillips 66 Partners LP common units — — 972 — 972 Other** (62 ) 31 (980 ) 969 (42 ) Net Cash Provided by (Used in) Financing Activities (2,352 ) (3,599 ) 417 5,356 (178 ) Effect of Exchange Rate Changes on Cash, Cash Equivalents and Restricted Cash — — 10 — 10 Net Change in Cash, Cash Equivalents and Restricted Cash — 279 (642 ) — (363 ) Cash, cash equivalents and restricted cash at beginning of period — 575 2,499 — 3,074 Cash, Cash Equivalents and Restricted Cash at End of Period $ — 854 1,857 — 2,711 * Revised to eliminate a purchase and sale transaction between two entities consolidated within the column. This revision increased net cash provided by operating activities by $1,049 million, with an offsetting decrease of $1,049 million in net cash provided by financing activities. The revision did not impact any issuer or guarantor column, nor did it impact our consolidated cash flows. ** Includes intercompany capital contributions. *** Includes return of investments in equity affiliates. Millions of Dollars Year Ended December 31, 2015 Statement of Cash Flows Phillips 66 Phillips 66 Company All Other Subsidiaries Consolidating Adjustments Total Consolidated Cash Flows From Operating Activities Net Cash Provided by Operating Activities $ 1,060 4,879 2,564 (2,790 ) 5,713 Cash Flows From Investing Activities Capital expenditures and investments* — (2,815 ) (5,283 ) 2,334 (5,764 ) Proceeds from asset dispositions** — 774 178 (882 ) 70 Intercompany lending activities 2,461 (3,153 ) 692 — — Advances/loans—related parties — (50 ) — — (50 ) Collection of advances/loans—related parties — 50 — — 50 Other — 6 (50 ) — (44 ) Net Cash Provided by (Used in) Investing Activities 2,461 (5,188 ) (4,463 ) 1,452 (5,738 ) Cash Flows From Financing Activities Issuance of debt — — 1,169 — 1,169 Repayment of debt (800 ) (23 ) (103 ) — (926 ) Issuance of common stock 31 — — — 31 Repurchase of common stock (1,512 ) — — — (1,512 ) Dividends paid on common stock (1,172 ) (1,172 ) (1,576 ) 2,748 (1,172 ) Distributions to controlling interests — — (186 ) 186 — Distributions to noncontrolling interests — — (46 ) — (46 ) Net proceeds from issuance of Phillips 66 Partners LP common units — — 384 — 384 Other* (68 ) 34 1,585 (1,596 ) (45 ) Net Cash Provided by (Used in) Financing Activities (3,521 ) (1,161 ) 1,227 1,338 (2,117 ) Effect of Exchange Rate Changes on Cash, Cash Equivalents and Restricted Cash — — 9 — 9 Net Change in Cash, Cash Equivalents and Restricted Cash — (1,470 ) (663 ) — (2,133 ) Cash, cash equivalents and restricted cash at beginning of period — 2,045 3,162 — 5,207 Cash, Cash Equivalents and Restricted Cash at End of Period $ — 575 2,499 — 3,074 * Includes intercompany capital contributions. ** Includes return of investments in equity affiliates.

Selected Quarterly Financial Da

Selected Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2017
Selected Quarterly Financial Information [Abstract]
Selected Quarterly Financial Data (Unaudited)	Selected Quarterly Financial Data (Unaudited) Millions of Dollars Per Share of Common Stock Sales and Other Operating Revenues* Income Before Income Taxes Net Income Net Income Attributable to Phillips 66 Net Income Attributable to Phillips 66 Basic Diluted 2017 First $ 22,894 797 563 535 1.02 1.02 Second 24,087 848 581 550 1.06 1.06 Third 25,627 1,256 849 823 1.60 1.60 Fourth** 29,746 654 3,255 3,198 6.29 6.25 2016 First $ 17,409 596 398 385 0.72 0.72 Second 21,849 720 516 496 0.94 0.93 Third 21,624 813 536 511 0.97 0.96 Fourth 23,397 62 194 163 0.31 0.31 * Includes excise taxes on sales of petroleum products. ** Includes a $2,721 million provisional income tax benefit from the enactment of the U.S. Tax Cuts and Jobs Act on December 22, 2017.

Subsequent Event

Subsequent Event	12 Months Ended
	Dec. 31, 2017
Subsequent Events [Abstract]
Subsequent Event	Subsequent Event On February 13, 2018, we entered into a Stock Purchase and Sale Agreement (Purchase Agreement) with Berkshire Hathaway Inc. and National Indemnity Company, a wholly owned subsidiary of Berkshire Hathaway, to repurchase 35 million shares of Phillips 66 common stock for an aggregate purchase price of approximately $3.3 billion . Pursuant to the Purchase Agreement, the purchase price per share of $93.725 was based on the volume-weighted-average price of our common stock on the New York Stock Exchange on February 13, 2018. The transaction closed on February 14, 2018. We funded the repurchase with cash on hand of approximately $1.9 billion and borrowings of approximately $1.4 billion under our commercial paper program. This specific share repurchase transaction was separately authorized by our Board of Directors and therefore does not impact previously announced authorizations which total up to $12.0 billion .

Summary of Significant Accoun40

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Consolidation Principles and Investments	Consolidation Principles and Investments —Our consolidated financial statements include the accounts of majority-owned, controlled subsidiaries and variable interest entities where we are the primary beneficiary. The equity method is used to account for investments in affiliates in which we have the ability to exert significant influence over the affiliates’ operating and financial policies. When we do not have the ability to exert significant influence, the investment is classified either as available-for-sale if fair value is readily determinable, or as the cost method if fair value is not readily determinable. Undivided interests in pipelines, natural gas plants and terminals are consolidated on a proportionate basis. Other securities and investments are generally carried at cost.
Recasted Financial Information	Recasted Financial Information —Certain prior period financial information has been recasted to reflect the current year’s presentation.
Foreign Currency Translation	Foreign Currency Translation —Adjustments resulting from the process of translating foreign functional currency financial statements into U.S. dollars are included in accumulated other comprehensive income (loss) in stockholders’ equity. Foreign currency transaction gains and losses result from remeasuring monetary assets and liabilities denominated in a foreign currency into the functional currency of our subsidiary holding the asset or liability. We include these transaction gains and losses in current earnings. Most of our foreign operations use their local currency as the functional currency.
Use of Estimates	Use of Estimates —The preparation of financial statements in conformity with generally accepted accounting principles in the United States requires management to make estimates and assumptions that affect the reported amounts of assets, liabilities, revenues and expenses, and the disclosures of contingent assets and liabilities. Actual results could differ from these estimates.
Revenue Recognition	Revenue Recognition —Revenues associated with sales of crude oil, natural gas liquids (NGL), petroleum and chemical products, and other items are recognized when title passes to the customer, which is when the risk of ownership passes to the purchaser and physical delivery of goods occurs, either immediately or within a fixed delivery schedule that is reasonable and customary in the industry. Revenues associated with transactions commonly called buy/sell contracts, in which the purchase and sale of inventory with the same counterparty are entered into in contemplation of one another, are combined and reported in the “Purchased crude oil and products” line on our consolidated statement of income (i.e., these transactions are recorded net).
Cash Equivalents	Cash Equivalents —Cash equivalents are highly liquid, short-term investments that are readily convertible to known amounts of cash and will mature within 90 days or less from the date of acquisition. We carry these investments at cost plus accrued interest.
Shipping and Handling Costs	Shipping and Handling Costs —We record shipping and handling costs in the “Purchased crude oil and products” line on our consolidated statement of income. Freight costs billed to customers are recorded in “Sales and other operating revenues.”
Inventories	Inventories —We have several valuation methods for our various types of inventories and consistently use the following methods for each type of inventory. Crude oil and petroleum products inventories are valued at the lower of cost or market in the aggregate, primarily on the last-in, first-out (LIFO) basis. Any necessary lower-of-cost-or-market write-downs at year end are recorded as permanent adjustments to the LIFO cost basis. LIFO is used to better match current inventory costs with current revenues and to meet tax-conformity requirements. Costs include both direct and indirect expenditures incurred in bringing an item or product to its existing condition and location. Materials and supplies inventories are valued using the weighted-average-cost method.
Fair Value Measurements	Fair Value Measurements —We categorize assets and liabilities measured at fair value into one of three different levels depending on the observability of the inputs employed in the measurement. Level 1 inputs are quoted prices in active markets for identical assets or liabilities. Level 2 inputs are inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly, through market-corroborated inputs. Level 3 inputs are unobservable inputs for the asset or liability that are used to measure fair value to the extent that relevant observable inputs are not available, and that reflect the assumptions we believe market participants would use when pricing an asset or liability for which there is little, if any, market activity at the measurement date. Fair Value Measurements We carry certain assets and liabilities at fair value, which we measure at the reporting date using an exit price (i.e., the price that would be received to sell an asset or paid to transfer a liability), and disclose the quality of these fair values based on the valuation inputs used in these measurements under the following hierarchy: • Level 1: Fair value measured with unadjusted quoted prices from an active market for identical assets or liabilities. • Level 2: Fair value measured either with: (1) adjusted quoted prices from an active market for similar assets or liabilities; or (2) other valuation inputs that are directly or indirectly observable. • Level 3: Fair value measured with unobservable inputs that are significant to the measurement. We classify the fair value of an asset or liability based on the significance of its observable or unobservable inputs to the measurement. However, the fair value of an asset or liability initially reported as Level 3 will be subsequently reported as Level 2 if the unobservable inputs become inconsequential to its measurement or corroborating market data becomes available. Conversely, an asset or liability initially reported as Level 2 will be subsequently reported as Level 3 if corroborating market data becomes unavailable.
Derivative Instruments	Derivative Instruments —Derivative instruments are recorded on the balance sheet at fair value. We have elected to net derivative assets and liabilities with the same counterparty on the balance sheet if the right of offset exists and certain other criteria are met. We also net collateral payables or receivables against derivative assets and derivative liabilities, respectively. Recognition and classification of the gain or loss that results from recording and adjusting a derivative to fair value depends on the purpose for issuing or holding the derivative. All realized and unrealized gains and losses from derivative instruments for which we do not apply hedge accounting are immediately recognized in our consolidated statement of income. Unrealized gains or losses from derivative instruments that qualify for and are designated as a cash flow hedge are recognized in other comprehensive income (loss) and appear on the balance sheet in accumulated other comprehensive income (loss) until the hedged transaction is recognized in earnings; however, to the extent the change in the fair value of a derivative instrument exceeds the change in the anticipated cash flows of the hedged transaction, the excess gain or loss is recognized immediately in earnings.
Capitalized Interest	Capitalized Interest —A portion of interest from external borrowings is capitalized on major projects with an expected construction period of one year or longer. Capitalized interest is added to the cost of the related asset, and is amortized over the useful life of the related asset.
Loans and Long-term Receivables	Loans and Long-Term Receivables —We enter into agreements with other parties to pursue business opportunities, which may require us to provide loans or advances to certain affiliated and non-affiliated companies. Loans are recorded when cash is transferred or seller financing is provided to the affiliated or non-affiliated company pursuant to a loan agreement. The loan balance will increase as interest is earned on the outstanding loan balance and will decrease as interest and principal payments are received. Interest is earned at the loan agreement’s stated interest rate. Loans and long-term receivables are assessed for impairment when events indicate the loan balance may not be fully recovered.
Intangible Assets Other Than Goodwill	Intangible Assets Other Than Goodwill —Intangible assets with finite useful lives are amortized using the straight-line method over their useful lives. Intangible assets with indefinite useful lives are not amortized but are tested at least annually for impairment. Each reporting period, we evaluate the remaining useful lives of intangible assets not being amortized to determine whether events and circumstances continue to support indefinite useful lives. Indefinite-lived intangible assets are considered impaired if their fair value is lower than their net book value. The fair value of intangible assets is determined based on quoted market prices in active markets, if available. If quoted market prices are not available, the fair value of intangible assets is determined based upon the present values of expected future cash flows using discount rates and other assumptions believed to be consistent with those used by principal market participants, or upon estimated replacement cost, if expected future cash flows from the intangible asset are not determinable.
Goodwill	Goodwill —Goodwill represents the excess of the purchase price over the estimated fair value of the net assets acquired in a business combination. It is not amortized, but is tested for impairment annually and when events or changes in circumstance indicate that the fair value of a reporting unit with goodwill is below its carrying value. The impairment test requires allocating goodwill and other assets and liabilities to reporting units. The fair value of each reporting unit is determined and compared to the book value of the reporting unit. If the fair value of the reporting unit is less than the book value, an impairment is recognized for the amount by which the book value exceeds the reporting unit’s fair value. A goodwill loss cannot exceed the total amount of goodwill allocated to that reporting unit. For purposes of testing goodwill for impairment, we have three reporting units with goodwill balances: Transportation, Refining, and Marketing and Specialties.
Depreciation and Amortization	Depreciation and Amortization —Depreciation and amortization of properties, plants and equipment are determined by either the individual-unit-straight-line method or the group-straight-line method (for those individual units that are highly integrated with other units).
Impairment of Properties, Plants and Equipment	Impairment of Properties, Plants and Equipment —Properties, plants and equipment (PP&E) used in operations are assessed for impairment whenever changes in facts and circumstances indicate a possible significant deterioration in the future cash flows expected to be generated by an asset group. If indicators of potential impairment exist, an undiscounted cash flow test is performed. If the sum of the undiscounted pre-tax cash flows is less than the carrying value of the asset group, including applicable liabilities, the carrying value of the PP&E included in the asset group is written down to estimated fair value through additional amortization or depreciation provisions and reported in the “Impairments” line on our consolidated statement of income in the period in which the determination of the impairment is made. Individual assets are grouped for impairment purposes at the lowest level for which identifiable cash flows are largely independent of the cash flows of other groups of assets (for example, at a refinery complex level). Because there is usually a lack of quoted market prices for long-lived assets, the fair value of impaired assets is typically determined using one or more of the following methods: the present values of expected future cash flows using discount rates and other assumptions believed to be consistent with those used by principal market participants; a market multiple of earnings for similar assets; or historical market transactions of similar assets, adjusted using principal market participant assumptions when necessary. Long-lived assets held for sale are accounted for at the lower of amortized cost or fair value, less cost to sell, with fair value determined using a binding negotiated price, if available, or present value of expected future cash flows as previously described. The expected future cash flows used for impairment reviews and related fair value calculations are based on estimated future volumes, prices, costs, margins and capital project decisions, considering all available evidence at the date of review.
Impairment of Investments in Nonconsolidated Entities	Impairment of Investments in Nonconsolidated Entities —Investments in nonconsolidated entities are assessed for impairment whenever changes in the facts and circumstances indicate a loss in value has occurred. When indicators exist, the fair value is estimated and compared to the investment carrying value. If any impairment is judgmentally determined to be other than temporary, the carrying value of the investment is written down to fair value. The fair value of the impaired investment is based on quoted market prices, if available, or upon the present value of expected future cash flows using discount rates and other assumptions believed to be consistent with those used by principal market participants and a market analysis of comparable assets, if appropriate.
Maintenance and Repairs	Maintenance and Repairs —Costs of maintenance and repairs, which are not significant improvements, are expensed when incurred. Major refinery maintenance turnarounds are expensed as incurred.
Property Dispositions	Property Dispositions —When complete units of depreciable property are sold, the asset cost and related accumulated depreciation are eliminated, with any gain or loss reflected in the “Net gain on dispositions” line on our consolidated statement of income. When less than complete units of depreciable property are disposed of or retired, the difference between asset cost and salvage value is charged or credited to accumulated depreciation.
Asset Retirement Obligations and Environmental Costs	Asset Retirement Obligations and Environmental Costs —The fair value of legal obligations to retire and remove long-lived assets are recorded in the period in which the obligation arises. When the liability is initially recorded, we capitalize this cost by increasing the carrying amount of the related PP&E. Over time, the liability is increased for the change in its present value, and the capitalized cost in PP&E is depreciated over the useful life of the related asset. If our estimate of the liability changes after initial recognition, we record an adjustment to the liability and PP&E. Environmental expenditures are expensed or capitalized, depending upon their future economic benefit. Expenditures relating to an existing condition caused by past operations, and those having no future economic benefit, are expensed. Liabilities for environmental expenditures are recorded on an undiscounted basis (unless acquired in a business combination) when environmental assessments or cleanups are probable and the costs can be reasonably estimated. Recoveries of environmental remediation costs from other parties, such as state reimbursement funds, are recorded as assets when their receipt is probable and estimable.
Guarantees	Guarantees —The fair value of a guarantee is determined and recorded as a liability at the time the guarantee is given. The initial liability is subsequently reduced as we are released from exposure under the guarantee. We amortize the guarantee liability over the relevant time period, if one exists, based on the facts and circumstances surrounding each type of guarantee. In cases where the guarantee term is indefinite, we reverse the liability when we have information indicating the liability has essentially been relieved or amortize it over an appropriate time period as the fair value of our guarantee exposure declines over time. We amortize the guarantee liability to the related income statement line item based on the nature of the guarantee. When it becomes probable we will have to perform on a guarantee, we accrue a separate liability for the excess amount above the guarantee’s book value, if it is reasonably estimable, based on the facts and circumstances at that time. We reverse the fair value liability only when there is no further exposure under the guarantee.
Stock-Based Compensation	Share-Based Compensation —We recognize share-based compensation expense over the shorter of: (1) the service period (i.e., the stated period of time required to earn the award); or (2) the period beginning at the start of the service period and ending when an employee first becomes eligible for retirement, but not less than six months as this is the minimum period of time required for an award not to be subject to forfeiture. Our equity-classified programs generally provide accelerated vesting (i.e., a waiver of the remaining period of service required to earn an award) for awards held by employees at the time they become eligible for retirement (at age 55 with 5 years of service). We have elected to recognize expense on a straight-line basis over the service period for the entire award, irrespective of whether the award was granted with ratable or cliff vesting, and elected to recognize forfeiture reversals of awards when they occur.
Income Taxes	Income Taxes —Income taxes are accounted for under the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. Interest related to unrecognized income tax benefits is reflected in interest expense, and penalties in operating expenses.
Taxes Collected from Customers and Remitted to Government Authorities	Taxes Collected from Customers and Remitted to Governmental Authorities —Excise taxes are reported gross within sales and other operating revenues and taxes other than income taxes, while other sales and value-added taxes are recorded net in taxes other than income taxes.
Treasury Stock	Treasury Stock —We record treasury stock purchases at cost, which includes incremental direct transaction costs. Amounts are recorded as reductions in stockholders’ equity in the consolidated balance sheet.
Earnings Per Share	The numerator of basic earnings per share (EPS) is net income attributable to Phillips 66, reduced by noncancelable dividends paid on unvested share-based employee awards during the vesting period (participating securities). The denominator of basic EPS is the sum of the daily weighted-average number of common shares outstanding during the periods presented and fully vested stock and unit awards that have not yet been issued as common stock. The numerator of diluted EPS is also based on net income attributable to Phillips 66, which is reduced only by dividend equivalents paid on participating securities for which the dividends are more dilutive than the participation of the awards in the earnings of the periods presented. To the extent unvested stock, unit or option awards and vested unexercised stock options are dilutive, they are included with the weighted-average common shares outstanding in the denominator. Treasury stock is excluded from the denominator in both basic and diluted EPS.
Contingencies and Commitments	In the case of all known contingencies (other than those related to income taxes), we accrue a liability when the loss is probable and the amount is reasonably estimable. If a range of amounts can be reasonably estimated and no amount within the range is a better estimate than any other amount, then the minimum of the range is accrued. We do not reduce these liabilities for potential insurance or third-party recoveries. If applicable, we accrue receivables for probable insurance or other third-party recoveries. In the case of income-tax-related contingencies, we use a cumulative probability-weighted loss accrual in cases where sustaining a tax position is less than certain.
New Accounting Pronouncements	Effective January 1, 2017, we early adopted Financial Accounting Standards Board (FASB) Accounting Standards Update (ASU) No. 2017-04, “Intangibles—Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment,” which eliminated the second step from the goodwill impairment test. Under the revised test, an entity should perform its goodwill impairment tests by comparing the fair value of a reporting unit with its carrying amount. An entity should recognize an impairment charge for the amount by which the carrying amount exceeds the reporting unit’s fair value; however, the loss recognized should not exceed the total amount of goodwill allocated to that reporting unit. This ASU was applied prospectively to goodwill impairment tests performed on or after January 1, 2017. Effective January 1, 2017, we early adopted ASU No. 2016-18, “Statement of Cash Flows (Topic 230): Restricted Cash.” The update clarified the classification and presentation of changes in restricted cash. The ASU requires that a statement of cash flows explain the change during the period in the total of cash, cash equivalents and amounts generally described as restricted cash and restricted cash equivalents. Adoption of this ASU on a retrospective basis did not have a material impact on our financial statements. See Note 23—Cash Flow Information for more information. Effective January 1, 2017, we early adopted ASU No. 2016-15, “Statement of Cash Flows (Topic 230): Classification of Certain Cash Receipts and Cash Payments.” The update clarified how certain cash receipts and cash payments should be presented and classified in the statement of cash flows. In addition, the ASU clarified that when cash receipts and cash payments have aspects of more than one class of cash flows and cannot be separated, classification will depend on the predominant source or use. Adoption of this ASU on a retrospective basis did not have a material impact on our financial statements. Effective January 1, 2017, we adopted ASU No. 2016-09, “Compensation—Stock Compensation (Topic 718): Improvements to Employee Share-Based Payment Accounting,” which simplified several aspects of the accounting for share-based payment award transactions, including accounting for income taxes and classification of excess tax benefits on the statement of cash flows, forfeitures and minimum statutory tax withholding requirements. Adoption of this ASU on a prospective basis did not materially impact our financial position, results of operations, or cash flows. We account for forfeitures of awards when they occur and excess tax benefits, which were previously reported in cash flows from financing activities, are now reported in cash flows from operating activities. In June 2014, the FASB issued ASU No. 2014-10, “Development Stage Entities (Topic 915): Elimination of Certain Financial Reporting Requirements, Including an Amendment to Variable Interest Entities (VIE) Guidance in Topic 810, Consolidation.” This update removed the definition of a development stage entity from the Master Glossary of the Accounting Standard Codification (ASC) and the related financial reporting requirements specific to development stage entities. This update was intended to reduce cost and complexity of financial reporting for entities that have not commenced planned principal operations. For financial reporting requirements other than the VIE guidance in ASC Topic 810, ASU No. 2014-10 was effective for annual and quarterly reporting periods of public entities beginning after December 15, 2014. For the financial reporting requirements related to VIEs in ASC Topic 810, ASU No. 2014-10 was effective for annual and quarterly reporting periods for public entities beginning after December 15, 2015. We adopted the provisions of this ASU related to the financial reporting requirements other than the VIE guidance effective January 1, 2015. We adopted the remaining provisions effective January 1, 2016. New Accounting Standards In February 2017, the FASB issued ASU No. 2017-05, “Other Income—Gains and Losses from the Derecognition of Nonfinancial Assets (Subtopic 610-20).” This ASU clarifies the scope and accounting for the sale or transfer of nonfinancial assets and in substance nonfinancial assets to noncustomers, including partial sales. This ASU will eliminate the use of carryover basis for most nonmonetary exchanges, including contributions of assets to equity method joint ventures. These amendments could result in the entity recognizing a gain or loss on the sale or transfer of nonfinancial assets. Public entities should apply the guidance in ASU No. 2017-05 to annual periods beginning after December 15, 2017, including interim periods within those periods. There was no impact on our financial statements from adopting this ASU on January 1, 2018. In January 2017, the FASB issued ASU No. 2017-01, “Business Combinations (Topic 805): Clarifying the Definition of a Business,” which clarifies the definition of a business with the objective of adding guidance to assist in evaluating whether transactions should be accounted for as acquisitions of assets or businesses. The amendment provides a screen for determining when a transaction involves an acquisition of a business. If substantially all of the fair value of the gross assets acquired is concentrated in a single identifiable asset, or a group of similar identifiable assets, then the transaction is not considered an acquisition of a business. If the screen is not met, then the amendment requires that to be considered a business, the operation must include at a minimum an input and a substantive process that together significantly contribute to the ability to create an output. The guidance may reduce the number of transactions accounted for as business acquisitions. Public business entities should apply the guidance in ASU No. 2017-01 to annual periods beginning after December 15, 2017, including interim periods within those periods, with early adoption permitted. The amendments should be applied prospectively and no disclosures are required at the effective date. There was no impact on our financial statements from adopting this ASU on January 1, 2018. In June 2016, the FASB issued ASU No. 2016-13, “Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments.” The new standard amends the impairment model to utilize an expected loss methodology in place of the currently used incurred loss methodology, which may result in earlier recognition of losses. Public business entities should apply the guidance in ASU No. 2016-13 for annual periods beginning after December 15, 2019, including interim periods within those annual periods. Early adoption will be permitted for annual periods beginning after December 15, 2018. We are currently evaluating the provisions of ASU No. 2016-13 and assessing the impact on our financial statements. In February 2016, the FASB issued ASU No. 2016-02, “Leases (Topic 842).” The new standard establishes a right-of-use (ROU) model that requires a lessee to record a ROU asset and a lease liability on the balance sheet for all leases with terms longer than 12 months. Leases will continue to be classified as either finance or operating, with classification affecting the pattern of expense recognition in the income statement. Similarly, lessors will be required to classify leases as sales-type, finance or operating, with classification affecting the pattern of income recognition. Classification for both lessees and lessors will be based on an assessment of whether risks and rewards as well as substantive control have been transferred through a lease contract. Public business entities should apply the guidance in ASU No. 2016-02 for annual periods beginning after December 15, 2018, including interim periods within those annual periods. Early adoption is permitted. Entities are required to adopt the ASU using a modified retrospective approach, subject to certain optional practical expedients, and apply the provisions of ASU No. 2016-02 to leasing arrangements existing at or entered into after the earliest comparative period presented in the financial statements. We are currently evaluating the provisions of ASU No. 2016-02 and assessing its impact on our financial statements. As part of our assessment to-date, we have formed an implementation team, commenced identification of our lease population and selected a lease software package. We expect the adoption of ASU 2016-02 will materially gross up our consolidated balance sheet with the recognition of the ROU assets and operating lease liabilities. The impact to our consolidated statements of income and cash flows is not expected to be material. The new standard will also require additional disclosures for financing and operating leases. In January 2016, the FASB issued ASU No. 2016-01, “Financial Instruments—Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities,” to meet its objective of providing more decision-useful information about financial instruments. The majority of this ASU’s provisions amend only the presentation or disclosures of financial instruments; however, one provision will also affect net income. Equity investments carried under the cost method or lower of cost or fair value method of accounting, in accordance with current GAAP, will have to be carried at fair value upon adoption of ASU No. 2016-01, with changes in fair value recorded in net income. For equity investments that do not have readily determinable fair values, a company may elect to carry such investments at cost less impairments, if any, adjusted up or down for price changes in similar financial instruments issued by the investee, when and if observed. Public business entities should apply the guidance in ASU No. 2016-01 for annual periods beginning after December 15, 2017, and interim periods within those annual periods, with early adoption prohibited. We are currently evaluating the provisions of ASU No. 2016-01. Our initial review indicates that ASU No. 2016-01 will have a limited impact on our financial statements. In May 2014, the FASB issued ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606).” This ASU and other related updates are intended to improve comparability of revenue recognition practices across entities, industries, jurisdictions and capital markets and expand disclosure requirements. In August 2015, the FASB issued ASU No. 2015-14, “Revenue from Contracts with Customers (Topic 606): Deferral of the Effective Date.” The amendment in this ASU defers the effective date of ASU No. 2014-09 for all entities for one year. Public business entities should apply the guidance in ASU No. 2014-09 to annual reporting periods beginning after December 15, 2017, including interim reporting periods within that reporting period. Our assessment work primarily included the formation of an implementation work team, training on the new ASU’s revenue recognition model, contract review and documentation and the monitoring of industry interpretative issues. We adopted the standard on January 1, 2018, using the modified retrospective application. Our evaluation of the new ASU is near completion, which includes understanding the impact of adoption on earnings from equity method investments. Based upon our analysis to-date, the primary impact of adoption of the new standard is the netting of sales-based taxes collected from our customers against revenue. Sales-based taxes include excise taxes on sales of petroleum products as noted on our consolidated statement of income. We have not identified any other material impact on our financial statements other than disclosures.

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	12 Months Ended
	Dec. 31, 2017
Variable Interest Entities [Abstract]
Variable Interest Assets	The most significant assets of Phillips 66 Partners that are available to settle only its obligations, along with its most significant liabilities for which its creditors do not have recourse to Phillips 66’s general credit at December 31 were: Millions of Dollars 2017 2016 Cash and cash equivalents $ 185 2 Equity investments* 1,932 1,142 Net properties, plants and equipment 2,918 2,675 Long-term debt 2,920 2,396 * Included in “Investments and long-term receivables” on the Phillips 66 consolidated balance sheet.

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Dec. 31, 2017
Inventory Disclosure [Abstract]
Summary of Inventories	Inventories at December 31 consisted of the following: Millions of Dollars 2017 2016 Crude oil and petroleum products $ 3,106 2,883 Materials and supplies 289 267 $ 3,395 3,150

Investments, Loans and Long-T43

Investments, Loans and Long-Term Receivables (Tables)	12 Months Ended
	Dec. 31, 2017
Equity Method Investments and Joint Ventures [Abstract]
Schedule of Long Term Investments and Receivables	Components of investments, loans and long-term receivables at December 31 were: Millions of Dollars 2017 2016 Equity investments $ 13,733 13,102 Loans and long-term receivables 94 334 Other investments 114 98 $ 13,941 13,534
Summarized Financial Information for Equity Method Investments in Affiliated Companies	Summarized 100 percent financial information for all equity method investments in affiliated companies, combined, was: Millions of Dollars 2017 2016 2015 Revenues $ 35,523 30,605 33,126 Income before income taxes 3,956 3,206 3,180 Net income 3,764 2,960 3,158 Current assets 7,325 7,097 6,024 Noncurrent assets 49,950 50,163 46,047 Current liabilities 5,248 5,173 4,130 Noncurrent liabilities 13,743 13,709 11,493 Noncontrolling interests 2,549 2,260 2,404

Properties, Plants and Equipm44

Properties, Plants and Equipment (Tables)	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Properties, Plants and Equipment with the Associated Accumulated Depreciation and Amortization	The company’s investment in PP&E, with the associated accumulated depreciation and amortization (Accum. D&A), at December 31 was: Millions of Dollars 2017 2016 Gross PP&E Accum. D&A Net PP&E Gross PP&E Accum. D&A Net PP&E Midstream $ 8,849 1,853 6,996 8,179 1,579 6,600 Chemicals — — — — — — Refining 22,144 8,987 13,157 21,152 8,197 12,955 Marketing and Specialties 1,658 909 749 1,451 776 675 Corporate and Other 1,091 533 558 1,207 582 625 $ 33,742 12,282 21,460 31,989 11,134 20,855

Goodwill and Intangibles (Table

Goodwill and Intangibles (Tables)	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Changes in Carrying Amount of Goodwill	The carrying amount of goodwill by segment at December 31 was: Millions of Dollars Midstream Refining Marketing and Specialties Total Balance at January 1, 2016 $ 623 1,813 839 3,275 Goodwill assigned to acquisitions 3 — — 3 Goodwill allocated to dispositions — (8 ) — (8 ) Balance at December 31, 2016 626 1,805 839 3,270 Adjustments — — — — Balance at December 31, 2017 $ 626 1,805 839 3,270
Schedule of Changes in Carrying Value of Intangible Assets	The gross carrying value of indefinite-lived intangible assets at December 31 consisted of the following: Millions of Dollars 2017 2016 Trade names and trademarks $ 503 503 Refinery air and operating permits 252 260 Other 1 1 $ 756 764

Asset Retirement Obligations 46

Asset Retirement Obligations and Accrued Environmental Costs (Tables)	12 Months Ended
	Dec. 31, 2017
Asset Retirement Obligation and Accrual for Environmental Cost Disclosure [Abstract]
Schedule of Asset Retirement Obligations and Accrual for Environmental Costs	Asset retirement obligations and accrued environmental costs at December 31 were: Millions of Dollars 2017 2016 Asset retirement obligations $ 268 244 Accrued environmental costs 458 496 Total asset retirement obligations and accrued environmental costs 726 740 Asset retirement obligations and accrued environmental costs due within one year* (85 ) (85 ) Long-term asset retirement obligations and accrued environmental costs $ 641 655 * Classified as a current liability on the consolidated balance sheet, under the caption “Other accruals.”
Schedule of Change in Asset Retirement Obligation	During 2017 and 2016 , our overall asset retirement obligation changed as follows: Millions of Dollars 2017 2016 Balance at January 1 $ 244 251 Accretion of discount 10 9 Changes in estimates of existing obligations 17 10 Spending on existing obligations (14 ) (15 ) Property dispositions — (5 ) Foreign currency translation 11 (6 ) Balance at December 31 $ 268 244

Earnings per Share (Tables)

Earnings per Share (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Reconciliation of Basic and Diluted Earnings Per Share	2017 2016 2015 Basic Diluted Basic Diluted Basic Diluted Amounts Attributed to Phillips 66 Common Stockholders (millions) : Net income attributable to Phillips 66 $ 5,106 5,106 1,555 1,555 4,227 4,227 Income allocated to participating securities (6 ) — (6 ) (5 ) (6 ) — Net income available to common stockholders $ 5,100 5,106 1,549 1,550 4,221 4,227 Weighted-average common shares outstanding (thousands) : 511,268 515,090 523,250 527,531 537,602 542,355 Effect of share-based compensation 3,822 3,418 4,281 2,535 4,753 4,622 Weighted-average common shares outstanding—EPS 515,090 518,508 527,531 530,066 542,355 546,977 Earnings Per Share of Common Stock (dollars) $ 9.90 9.85 2.94 2.92 7.78 7.73

Debt (Tables)

Debt (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Summary of Long Term Debt	Long-term debt at December 31 was: Millions of Dollars 2017 2016 2.950% Senior Notes due 2017 $ — 1,500 4.300% Senior Notes due 2022 2,000 2,000 4.650% Senior Notes due 2034 1,000 1,000 5.875% Senior Notes due 2042 1,500 1,500 4.875% Senior Notes due 2044 1,500 1,500 Phillips 66 Partners 2.646% Senior Notes due 2020 300 300 Phillips 66 Partners 3.605% Senior Notes due 2025 500 500 Phillips 66 Partners 3.550% Senior Notes due 2026 500 500 Phillips 66 Partners 3.750% Senior Notes due 2028 500 — Phillips 66 Partners 4.680% Senior Notes due 2045 450 300 Phillips 66 Partners 4.900% Senior Notes due 2046 625 625 Floating-rate notes due 2019 at 2.009% at year-end 2017 300 — Floating-rate notes due 2020 at 2.109% at year-end 2017 300 — Term loan due 2020 at 2.469% at year-end 2017 450 — Note payable to MSLP due 2020 at 7.00%* — 68 Industrial Development Bonds due 2018 through 2021 at 0.80%-2.09% at year-end 2017 and 0.57%-0.81% at year-end 2016* 100 50 Phillips 66 Partners revolving credit facility due 2021 at 1.98% at year-end 2016 — 210 Other 1 1 Debt at face value 10,026 10,054 Capitalized leases 192 188 Net unamortized discounts and debt issuance costs (108 ) (104 ) Total debt 10,110 10,138 Short-term debt (41 ) (550 ) Long-term debt $ 10,069 9,588 * In February 2017, MSLP became a consolidated subsidiary, see Note 5—Business Combinations.

Derivatives and Financial Ins49

Derivatives and Financial Instruments (Tables)	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Fair Value, by Balance Sheet Grouping	The following table indicates the consolidated balance sheet line items that include the fair values of commodity derivative assets and liabilities. The balances in the following table are presented on a gross basis, before the effects of counterparty and collateral netting. However, we have elected to present our commodity derivative assets and liabilities with the same counterparty on a net basis on our consolidated balance sheet when the right of setoff exists. Millions of Dollars December 31, 2017 December 31, 2016 Commodity Derivatives Effect of Collateral Netting Net Carrying Value Presented on the Balance Sheet Commodity Derivatives Effect of Collateral Netting Net Carrying Value Presented on the Balance Sheet Assets Liabilities Assets Liabilities Assets Prepaid expenses and other current assets $ 43 (19 ) — 24 267 (154 ) — 113 Other assets 7 (3 ) — 4 5 (1 ) — 4 Liabilities Other accruals 699 (746 ) 21 (26 ) 474 (612 ) 73 (65 ) Other liabilities and deferred credits — (1 ) — (1 ) — (1 ) — (1 ) Total $ 749 (769 ) 21 1 746 (768 ) 73 51
Summary of Fair Value of Commodity Derivative Assets and Liabilities and Gains (Losses) From Derivative Contracts	The realized and unrealized gains (losses) incurred from commodity derivatives, and the line items where they appear on our consolidated statement of income, were: Millions of Dollars 2017 2016 2015 Sales and other operating revenues $ (247 ) (451 ) 162 Other income 27 29 58 Purchased crude oil and products (18 ) (62 ) 121 Net gain (loss) from commodity derivative activity $ (238 ) (484 ) 341
Summary of Material Net Exposures from Outstanding Commodity Derivative Contracts	Open Position Long / (Short) 2017 2016 Commodity Crude oil, refined products and NGL (millions of barrels) (11 ) (18 )

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value Hierarchy for Material Financial Instruments and Derivative Assets and Liabilities, Including the Effect of Counterparty Netting	The carrying values and fair values by hierarchy of our material financial instruments and commodity forward contracts, either carried or disclosed at fair value, including any effects of netting derivative assets with liabilities and netting collateral due to right of setoff or master netting agreements, were: Millions of Dollars December 31, 2017 Fair Value Hierarchy Total Fair Value of Gross Assets & Liabilities Effect of Counterparty Netting Effect of Collateral Netting Difference in Carrying Value and Fair Value Net Carrying Value Presented on the Balance Sheet Level 1 Level 2 Level 3 Commodity Derivative Assets Exchange-cleared instruments $ 333 395 — 728 (721 ) — — 7 Physical forward contracts — 20 1 21 — — — 21 Interest rate derivatives — 14 — 14 — — — 14 Rabbi trust assets 112 — — 112 N/A N/A — 112 $ 445 429 1 875 (721 ) — — 154 Commodity Derivative Liabilities Exchange-cleared instruments $ 369 373 — 742 (721 ) (21 ) — — Physical forward contracts — 23 4 27 — — — 27 Floating-rate debt — 1,150 — 1,150 N/A N/A — 1,150 Fixed-rate debt, excluding capital leases — 9,746 — 9,746 N/A N/A (978 ) 8,768 $ 369 11,292 4 11,665 (721 ) (21 ) (978 ) 9,945 Millions of Dollars December 31, 2016 Fair Value Hierarchy Total Fair Value of Gross Assets & Liabilities Effect of Counterparty Netting Effect of Collateral Netting Difference in Carrying Value and Fair Value Net Carrying Value Presented on the Balance Sheet Level 1 Level 2 Level 3 Commodity Derivative Assets Exchange-cleared instruments $ 273 371 — 644 (628 ) — — 16 OTC instruments — 6 — 6 (1 ) — — 5 Physical forward contracts — 94 2 96 — — — 96 Interest rate derivatives — 8 — 8 — — — 8 Rabbi trust assets 97 — — 97 N/A N/A — 97 $ 370 479 2 851 (629 ) — — 222 Commodity Derivative Liabilities Exchange-cleared instruments $ 249 452 — 701 (628 ) (73 ) — — OTC instruments — 1 — 1 (1 ) — — — Physical forward contracts — 61 5 66 — — — 66 Floating-rate debt — 260 — 260 N/A N/A — 260 Fixed-rate debt, excluding capital leases — 10,260 — 10,260 N/A N/A (570 ) 9,690 $ 249 11,034 5 11,288 (629 ) (73 ) (570 ) 10,016

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2017
Leases [Abstract]
Schedule of Future Minimum Lease Payments	Future minimum lease payments at December 31, 2017 , for operating and capital lease obligations were: Millions of Dollars Capital Lease Obligations Operating Lease Obligations* 2018 $ 22 533 2019 22 420 2020 18 306 2021 18 141 2022 15 100 Remaining years 148 326 Total 243 1,826 Less: income from subleases — 71 Net minimum lease payments $ 243 1,755 Less: amount representing interest 51 Capital lease obligations $ 192 * Includes the remaining residual value deficiency on our railcar leases. See Note 13—Guarantees, for additional information.
Schedule of Operating Lease Rental Expense	Operating lease rental expense for the years ended December 31 was: Millions of Dollars 2017 2016 2015 Minimum rentals* $ 680 669 641 Contingent rentals 6 6 6 Less: sublease rental income 73 95 136 $ 613 580 511 * Includes expenses related to the residual value deficiency on our railcar leases. See Note 13—Guarantees, for additional information.

Pension and Postretirement Pl52

Pension and Postretirement Plans (Tables)	12 Months Ended
	Dec. 31, 2017
Retirement Benefits [Abstract]
Reconciliation of Projected Benefit Obligations and Plan Assets	The following table provides a reconciliation of the projected benefit obligations and plan assets for our pension plans and accumulated benefit obligations for our other postretirement benefit plans: Millions of Dollars Pension Benefits Other Benefits 2017 2016 2017 2016 U.S. Int’l. U.S. Int’l. Change in Benefit Obligation Benefit obligation at January 1 $ 2,881 1,055 2,791 912 225 219 Service cost 132 32 127 32 6 7 Interest cost 108 27 116 28 8 8 Plan participant contributions — 2 — 3 3 2 Actuarial loss (gain) 267 (5 ) 62 237 6 (6 ) Benefits paid (345 ) (20 ) (215 ) (19 ) (16 ) (13 ) Curtailment gain — — — (31 ) — — Acquisition of a business — — — — — 8 Foreign currency exchange rate change — 118 — (107 ) — — Benefit obligation at December 31 $ 3,043 1,209 2,881 1,055 232 225 Change in Fair Value of Plan Assets Fair value of plan assets at January 1 $ 2,274 796 2,023 742 — — Actual return on plan assets 399 71 136 148 — — Company contributions 423 35 330 40 13 11 Plan participant contributions — 2 — 3 3 2 Benefits paid (345 ) (20 ) (215 ) (19 ) (16 ) (13 ) Foreign currency exchange rate change — 88 — (118 ) — — Fair value of plan assets at December 31 $ 2,751 972 2,274 796 — — Funded Status at December 31 $ (292 ) (237 ) (607 ) (259 ) (232 ) (225 )
Amounts Recognized in the Consolidated Balance Sheet	Amounts recognized in the consolidated balance sheet for our pension and other postretirement benefit plans at December 31, 2017 and 2016 , include: Millions of Dollars Pension Benefits Other Benefits 2017 2016 2017 2016 U.S. Int’l. U.S. Int’l. Amounts Recognized in the Consolidated Balance Sheet at December 31 Current liabilities $ (25 ) — (10 ) — (16 ) (10 ) Noncurrent liabilities (267 ) (237 ) (597 ) (259 ) (216 ) (215 ) Total recognized $ (292 ) (237 ) (607 ) (259 ) (232 ) (225 )
Before Tax Amounts Unrecognized in Net Periodic Benefit Cost Included in Accumulated Other Comprehensive Income	Included in accumulated other comprehensive income (loss) at December 31 were the following before-tax amounts that had not been recognized in net periodic benefit cost: Millions of Dollars Pension Benefits Other Benefits 2017 2016 2017 2016 U.S. Int’l. U.S. Int’l. Unrecognized net actuarial loss (gain) $ 545 190 684 227 1 (5 ) Unrecognized prior service cost (credit) — (4 ) 3 (5 ) (7 ) (9 )
Sources of Change in Other Comprehensive Income	Millions of Dollars Pension Benefits Other Benefits 2017 2016 2017 2016 U.S. Int’l. U.S. Int’l. Sources of Change in Other Comprehensive Income (Loss) Net gain (loss) arising during the period $ (14 ) 14 (54 ) (129 ) (6 ) 7 Curtailment gain — — — 31 — — Amortization of loss and settlements included in income 153 23 80 14 — — Net change in unrecognized net actuarial loss (gain) during the period $ 139 37 26 (84 ) (6 ) 7 Prior service cost arising during the period $ — — — — — — Amortization of prior service cost (credit) included in income 3 (1 ) 3 (1 ) (2 ) (1 ) Net change in unrecognized prior service cost (credit) during the period $ 3 (1 ) 3 (1 ) (2 ) (1 )
Schedule of Accumulated Benefit Obligations in Excess of Fair Value of Plan Assets	Information for U.S. and international pension plans with an accumulated benefit obligation in excess of plan assets at December 31 were: Millions of Dollars Pension Benefits 2017 2016 U.S. Int’l. U.S. Int’l. Projected benefit obligations $ 172 389 2,881 355 Accumulated benefit obligations 143 368 2,601 334 Fair value of plan assets — 196 2,274 166
Components of Net Periodic Benefit Cost	Components of net periodic benefit cost for all defined benefit plans are presented in the table below: Millions of Dollars Pension Benefits Other Benefits 2017 2016 2015 2017 2016 2015 U.S. Int’l. U.S. Int’l. U.S. Int’l. Components of Net Periodic Benefit Cost Service cost $ 132 32 127 32 124 38 6 7 7 Interest cost 108 27 116 28 109 28 8 8 7 Expected return on plan assets (146 ) (40 ) (128 ) (38 ) (138 ) (37 ) — — — Amortization of prior service cost (credit) 3 (1 ) 3 (1 ) 3 (1 ) (2 ) (1 ) (2 ) Recognized net actuarial loss (gain) 70 23 72 14 75 15 — — (1 ) Settlements 83 — 8 — 80 — — — — Total net periodic benefit cost $ 250 41 198 35 253 43 12 14 11
Amounts Included in Accumulated Other Comprehensive Income Expected to be Amortized into Net Periodic Benefit Cost Over the Next Fiscal Year	Amounts included in accumulated other comprehensive income (loss) at December 31, 2017 , that are expected to be amortized into net periodic benefit cost during 2018 are provided below: Millions of Dollars Pension Benefits Other Benefits U.S. Int’l. Unrecognized net actuarial loss $ 59 19 — Unrecognized prior service credit — (1 ) (1 )
Weighted-Average Assumptions Used to Determine Benefit Obligations and Net Periodic Benefit Costs	The following weighted-average assumptions were used to determine benefit obligations and net periodic benefit costs for years ended December 31: Pension Benefits Other Benefits 2017 2016 2017 2016 U.S. Int’l. U.S. Int’l. Assumptions Used to Determine Benefit Obligations: Discount rate 3.60 % 2.36 3.95 2.42 3.35 3.65 Rate of compensation increase 4.00 3.74 4.00 3.78 — — Assumptions Used to Determine Net Periodic Benefit Cost: Discount rate 3.95 % 2.46 4.35 3.35 3.65 4.00 Expected return on plan assets 6.75 4.74 6.75 5.31 — — Rate of compensation increase 4.00 3.78 4.00 3.65 — —
Fair Values of Pension Plan Assets	The fair values of our pension plan assets at December 31, by asset class, were: Millions of Dollars U.S. International Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total 2017 Equity securities $ 589 — — 589 — — — — Government debt securities 632 — — 632 — — — — Mutual funds 129 — — 129 — — — — Cash and cash equivalents 90 — — 90 6 — — 6 Insurance contracts — — — — — — 14 14 Real estate — — — — — — 8 8 Total assets in the fair value hierarchy 1,440 — — 1,440 6 — 22 28 Common/collective trusts measured at NAV 1,311 944 Total $ 1,440 — — 2,751 6 — 22 972 Millions of Dollars U.S. International Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total 2016 Equity securities $ 533 — — 533 — — — — Mutual funds 47 — — 47 — — — — Cash and cash equivalents 21 — — 21 5 — — 5 Insurance contracts — — — — — — 13 13 Real estate — — — — — — 6 6 Total assets in the fair value hierarchy 601 — — 601 5 — 19 24 Common/collective trusts measured at NAV 1,673 772 Total $ 601 — — 2,274 5 — 19 796
Expected Benefit Payments	The following benefit payments, which reflect expected future service, as appropriate, are expected to be paid by us in the years indicated: Millions of Dollars Pension Benefits Other Benefits U.S. Int’l. 2018 $ 329 22 27 2019 302 22 28 2020 294 24 27 2021 290 26 26 2022 292 27 24 2023-2026 1,298 162 101

Share-Based Compensation Plans

Share-Based Compensation Plans (Tables)	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-Based Compensation Expense Recognized in Income and the Associated Tax Benefit	Total share-based compensation expense recognized in income and the associated income tax benefit for the years ended December 31 were: Millions of Dollars 2017 2016 2015 Share-based compensation expense $ 142 156 144 Income tax benefit (74 ) (59 ) (54 )
Stock Option Activity	The following table summarizes our stock option activity from January 1, 2017 , to December 31, 2017 : Millions of Dollars Options Weighted- Average Exercise Price Weighted-Average Grant-Date Fair Value Aggregate Outstanding at January 1, 2017 5,103,130 $ 49.48 Granted 864,100 78.48 $ 16.95 Forfeited (32,500 ) 78.48 Exercised (1,095,875 ) 32.38 $ 62 Outstanding at December 31, 2017 4,838,855 $ 58.34 Vested at December 31, 2017 4,191,679 $ 55.25 $ 195 Exercisable at December 31, 2017 3,258,015 $ 48.79 $ 172
Significant Assumptions Used to Calculate Grant Date Fair Market Values of Options Granted	The following table provides the significant assumptions used to calculate the grant date fair values of options granted over the years shown below, as calculated using the Black-Scholes-Merton option-pricing model: 2017 2016 2015 Risk-free interest rate 2.28 % 1.71 1.60 Dividend yield 2.90 % 3.00 3.00 Volatility factor 26.91 % 28.68 34.17 Expected life (years) 7.22 7.08 6.66
Summary of Stock Unit Activity	The following table summarizes our RSU activity from January 1, 2017 , to December 31, 2017 : Millions of Dollars Stock Units Weighted-Average Grant-Date Fair Value Total Fair Value Outstanding at January 1, 2017 2,643,139 $ 71.28 Granted 975,164 78.49 Forfeited (58,171 ) 77.18 Issued (1,063,707 ) 63.67 $ 85 Outstanding at December 31, 2017 2,496,425 $ 77.20 Not Vested at December 31, 2017 1,615,668 $ 77.32
Summary of Performance Share Program Activity	The following table summarizes our PSU activity from January 1, 2017 , to December 31, 2017 : Millions of Dollars Performance Share Units Weighted-Average Grant-Date Fair Value Total Fair Value Outstanding at January 1, 2017 3,239,497 $ 50.12 Granted 642,212 86.88 Issued (681,219 ) 42.85 $ 54 Cash settled (642,212 ) 86.88 56 Outstanding at December 31, 2017 2,558,278 $ 52.06 Not Vested at December 31, 2017 286,031 $ 66.65

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Schedule of Components of Income Tax Expense	Components of income tax expense (benefit) were: Millions of Dollars 2017 2016 2015 Income Tax Expense (Benefit) Federal Current $ 9 (105 ) 1,128 Deferred (1,960 ) 645 444 Foreign Current 126 66 (74 ) Deferred 3 (84 ) 42 State and local Current 61 (24 ) 227 Deferred 68 49 (3 ) $ (1,693 ) 547 1,764
Schedule of Deferred Tax Assets and Liabilities	Major components of deferred tax liabilities and assets at December 31 were: Millions of Dollars 2017 2016 Deferred Tax Liabilities Properties, plants and equipment, and intangibles $ 2,942 4,525 Investment in joint ventures 1,923 2,442 Investment in subsidiaries 594 803 Inventory — 154 Other 18 19 Total deferred tax liabilities 5,477 7,943 Deferred Tax Assets Benefit plan accruals 314 669 Inventory 10 — Asset retirement obligations and accrued environmental costs 121 211 Other financial accruals and deferrals 44 188 Loss and credit carryforwards 96 261 Other 3 1 Total deferred tax assets 588 1,330 Less: valuation allowance 28 38 Net deferred tax assets 560 1,292 Net deferred tax liabilities $ 4,917 6,651
Schedule of Unrecognized Tax Benefits Roll Forward	Following is a reconciliation of the changes in our unrecognized income tax benefits balance: Millions of Dollars 2017 2016 2015 Balance at January 1 $ 70 82 142 Additions for tax positions of prior years 1 5 6 Reductions for tax positions of prior years (5 ) (17 ) (17 ) Settlements (32 ) — (49 ) Balance at December 31 $ 34 70 82
Schedule of Effective Income Tax Rate Reconciliation	The amounts of U.S. and foreign income before income taxes, with a reconciliation of income tax at the federal statutory rate to the recorded income tax expense (benefit), were: Millions of Dollars Percentage of Income Before Income Taxes 2017 2016 2015 2017 2016 2015 Income before income taxes United States $ 2,799 1,713 4,983 78.7 % 78.2 82.4 Foreign 756 478 1,061 21.3 21.8 17.6 $ 3,555 2,191 6,044 100.0 % 100.0 100.0 Federal statutory income tax $ 1,244 767 2,115 35.0 % 35.0 35.0 State income tax, net of federal benefit 79 12 150 2.2 0.6 2.5 Tax Cuts and Jobs Act (2,721 ) — — (76.5 ) — — Foreign rate differential (210 ) (152 ) (239 ) (5.9 ) (6.9 ) (3.9 ) Noncontrolling interests (46 ) (26 ) (13 ) (1.3 ) (1.2 ) (0.2 ) Federal manufacturing deduction (18 ) — (77 ) (0.5 ) — (1.3 ) Change in valuation allowance (4 ) (81 ) (17 ) (0.1 ) (3.7 ) (0.2 ) Goodwill allocated to assets sold — — 41 — — 0.7 German tax legislation — — (103 ) — — (1.7 ) Sale of foreign subsidiaries — — (125 ) — — (2.1 ) Other (17 ) 27 32 (0.5 ) 1.2 0.4 $ (1,693 ) 547 1,764 (47.6 )% 25.0 29.2

Accumulated Other Comprehensi55

Accumulated Other Comprehensive Income (Loss) (Tables)	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Accumulated Other Comprehensive Income (Loss)	Changes in the balances of each component of accumulated other comprehensive income (loss) were as follows: Millions of Dollars Defined Benefit Plans Foreign Currency Translation Hedging Accumulated Other Comprehensive Loss December 31, 2014 $ (696 ) 167 (2 ) (531 ) Other comprehensive loss before reclassification (78 ) (156 ) — (234 ) Amounts reclassified from accumulated other comprehensive loss* Amortization of defined benefit plan items** Actuarial losses and settlements 112 — — 112 Net current period other comprehensive income (loss) 34 (156 ) — (122 ) December 31, 2015 (662 ) 11 (2 ) (653 ) Other comprehensive income (loss) before reclassifications (112 ) (296 ) 5 (403 ) Amounts reclassified from accumulated other comprehensive loss* Amortization of defined benefit plan items** Actuarial losses and settlements 61 — — 61 Net current period other comprehensive income (loss) (51 ) (296 ) 5 (342 ) December 31, 2016 (713 ) (285 ) 3 (995 ) Other comprehensive income before reclassifications 3 259 4 266 Amounts reclassified from accumulated other comprehensive loss* Amortization of defined benefit plan items** Actuarial losses and settlements 112 — — 112 Net current period other comprehensive income 115 259 4 378 December 31, 2017 $ (598 ) (26 ) 7 (617 ) * There were no significant reclassifications related to foreign currency translation or hedging. ** Included in the computation of net periodic benefit cost. See Note 19—Pension and Postretirement Plans , for additional information.

Cash Flow Information (Tables)

Cash Flow Information (Tables)	12 Months Ended
	Dec. 31, 2017
Supplemental Cash Flow Information [Abstract]
Cash Flow Information	Millions of Dollars 2017 2016 2015 Cash Payments (Receipts) Interest $ 421 311 275 Income taxes* (257 ) (375 ) 1,560 * 2017 and 2016 reflected a net cash refund position; cash payments for income taxes were $102 million and $385 million in 2017 and 2016, respectively.

Other Financial Information (Ta

Other Financial Information (Tables)	12 Months Ended
	Dec. 31, 2017
Other Income and Expenses [Abstract]
Other Financial Information	Millions of Dollars 2017 2016 2015 Interest and Debt Expense Incurred Debt $ 432 402 389 Other 21 17 27 453 419 416 Capitalized (15 ) (81 ) (106 ) Expensed $ 438 338 310 Other Income Interest income $ 31 18 27 Gain on consolidation of business* 423 — — Other, net** 67 56 91 $ 521 74 118 * See Note 5—Business Combinations regarding the gain recognized in 2017. ** Includes derivatives-related activities. Research and Development Expenditures— expensed $ 60 60 65 Advertising Expenses $ 76 80 73 Foreign Currency Transaction (Gains) Losses— after-tax Midstream $ — — — Chemicals — — — Refining (1 ) (10 ) 34 Marketing and Specialties 1 1 4 Corporate and Other — (2 ) — $ — (11 ) 38

Related Party Transactions (Tab

Related Party Transactions (Tables)	12 Months Ended
	Dec. 31, 2017
Related Party Transactions [Abstract]
Significant Transactions with Related Parties	Significant transactions with related parties were: Millions of Dollars 2017 2016 2015 Operating revenues and other income (a) $ 2,596 2,174 2,452 Purchases (b) 10,468 8,109 8,142 Operating expenses and selling, general and administrative expenses (c) 79 125 129 As discussed more fully in Note 5—Business Combinations , in February 2017, we began accounting for MSLP as a consolidated subsidiary. Accordingly, the table above only includes processing fees paid to MSLP through the consolidation date. (a) We sold NGL and other petrochemical feedstocks, along with solvents, to CPChem, and we sold gas oil and hydrogen feedstocks to Excel Paralubes (Excel). We sold refined products to our OnCue Holdings, LLC joint venture. We sold certain feedstocks and intermediate products to WRB and also acted as agent for WRB in supplying crude oil and other feedstocks for a fee. In addition, we charged several of our affiliates, including CPChem, for the use of common facilities, such as steam generators, waste and water treaters, and warehouse facilities. (b) We purchased crude oil and refined products from WRB and also acted as agent for WRB in distributing solvents. We purchased natural gas and NGL from DCP Midstream and CPChem, as well as other feedstocks from various affiliates, for use in our refinery and fractionation processes. We paid NGL fractionation fees to CPChem. We also paid fees to various pipeline equity companies for transporting crude oil, refined products and NGL. We purchased base oils and fuel products from Excel for use in our refining and specialty businesses. (c) We paid utility and processing fees to various affiliates.

Segment Disclosures and Relat59

Segment Disclosures and Related Information (Tables)	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Analysis of Results by Operating Segment	Analysis of Results by Operating Segment Millions of Dollars 2017 2016 2015 Sales and Other Operating Revenues Midstream Total sales $ 6,620 4,226 3,676 Intersegment eliminations (1,842 ) (1,299 ) (1,034 ) Total Midstream 4,778 2,927 2,642 Chemicals 5 5 5 Refining Total sales 65,494 52,068 63,470 Intersegment eliminations (40,284 ) (34,120 ) (40,317 ) Total Refining 25,210 17,948 23,153 Marketing and Specialties Total sales 73,565 64,476 74,591 Intersegment eliminations (1,233 ) (1,109 ) (1,446 ) Total Marketing and Specialties 72,332 63,367 73,145 Corporate and Other 29 32 30 Consolidated sales and other operating revenues $ 102,354 84,279 98,975 Depreciation, Amortization and Impairments Midstream $ 299 218 128 Chemicals — — — Refining 838 770 741 Marketing and Specialties 116 107 100 Corporate and Other 89 78 116 Consolidated depreciation, amortization and impairments $ 1,342 1,173 1,085 Millions of Dollars 2017 2016 2015 Equity in Earnings of Affiliates Midstream $ 454 184 (268 ) Chemicals 713 834 1,316 Refining 322 164 325 Marketing and Specialties 243 232 207 Corporate and Other — — (7 ) Consolidated equity in earnings of affiliates $ 1,732 1,414 1,573 Income Tax Expense (Benefit) Midstream $ 174 123 73 Chemicals 191 256 353 Refining 672 61 1,104 Marketing and Specialties 334 370 466 Corporate and Other (3,064 ) (263 ) (232 ) Consolidated income tax expense (benefit) $ (1,693 ) 547 1,764 Net Income (Loss) Midstream $ 464 280 74 Chemicals 525 583 962 Refining 1,404 374 2,555 Marketing and Specialties 686 891 1,187 Corporate and Other 2,169 (484 ) (498 ) Consolidated net income $ 5,248 1,644 4,280 Millions of Dollars 2017 2016 2015 Investments In and Advances To Affiliates Midstream $ 4,734 4,769 4,198 Chemicals 6,222 5,773 5,177 Refining 2,398 2,420 2,262 Marketing and Specialties 390 391 342 Corporate and Other — 1 1 Consolidated investments in and advances to affiliates $ 13,744 13,354 11,980 Total Assets Midstream $ 13,231 12,832 11,043 Chemicals 6,226 5,802 5,237 Refining 23,820 22,825 21,993 Marketing and Specialties 7,103 6,227 5,631 Corporate and Other 3,991 3,967 4,676 Consolidated total assets $ 54,371 51,653 48,580 Capital Expenditures and Investments Midstream $ 771 1,453 4,457 Chemicals — — — Refining 853 1,149 1,069 Marketing and Specialties 108 98 122 Corporate and Other 100 144 116 Consolidated capital expenditures and investments $ 1,832 2,844 5,764 Interest Income and Expense Interest income Midstream $ 1 2 — Marketing and Specialties — — 2 Corporate and Other 30 16 25 Consolidated interest income $ 31 18 27 Interest and debt expense Corporate and Other $ 438 338 310
Sales and Other Operating Revenues by Product Line	Sales and Other Operating Revenues by Product Line Refined products $ 85,405 73,385 86,249 Crude oil resales 11,808 7,594 8,993 NGL 4,670 3,107 2,998 Other 471 193 735 Consolidated sales and other operating revenues by product line $ 102,354 84,279 98,975
Geographic Information	Geographic Information Millions of Dollars Sales and Other Operating Revenues* Long-Lived Assets** 2017 2016 2015 2017 2016 2015 United States $ 75,684 59,742 69,578 33,264 32,442 29,624 United Kingdom 10,626 9,895 12,120 1,254 1,177 1,459 Germany 6,692 6,128 6,584 591 503 502 Other foreign countries 9,352 8,514 10,693 95 87 116 Worldwide consolidated $ 102,354 84,279 98,975 35,204 34,209 31,701 * Sales and other operating revenues are attributable to countries based on the location of the operations generating the revenues. ** Defined as net properties, plants and equipment plus investments in and advances to affiliated companies.

Condensed Consolidating Finan60

Condensed Consolidating Financial Information (Tables)	12 Months Ended
	Dec. 31, 2017
Condensed Financial Information of Parent Company Only Disclosure [Abstract]
Condensed Consolidated Income Statement	Millions of Dollars Year Ended December 31, 2017 Statement of Income Phillips 66 Phillips 66 Company All Other Subsidiaries Consolidating Adjustments Total Consolidated Revenues and Other Income Sales and other operating revenues $ — 74,640 27,714 — 102,354 Equity in earnings of affiliates 5,336 3,256 559 (7,419 ) 1,732 Net gain on dispositions — 1 14 — 15 Other income 3 471 47 — 521 Intercompany revenues — 1,610 13,457 (15,067 ) — Total Revenues and Other Income 5,339 79,978 41,791 (22,486 ) 104,622 Costs and Expenses Purchased crude oil and products — 63,812 30,379 (14,782 ) 79,409 Operating expenses — 3,672 1,085 (58 ) 4,699 Selling, general and administrative expenses 7 1,300 399 (11 ) 1,695 Depreciation and amortization — 892 426 — 1,318 Impairments — 20 4 — 24 Taxes other than income taxes — 5,784 7,678 — 13,462 Accretion on discounted liabilities — 17 5 — 22 Interest and debt expense 348 70 236 (216 ) 438 Total Costs and Expenses 355 75,567 40,212 (15,067 ) 101,067 Income before income taxes 4,984 4,411 1,579 (7,419 ) 3,555 Income tax benefit (122 ) (925 ) (646 ) — (1,693 ) Net Income 5,106 5,336 2,225 (7,419 ) 5,248 Less: net income attributable to noncontrolling interests — — 142 — 142 Net Income Attributable to Phillips 66 $ 5,106 5,336 2,083 (7,419 ) 5,106 Comprehensive Income $ 5,484 5,714 2,498 (8,070 ) 5,626 Millions of Dollars Year Ended December 31, 2016 Statement of Income Phillips 66 Phillips 66 Company All Other Subsidiaries Consolidating Adjustments Total Consolidated Revenues and Other Income Sales and other operating revenues $ — 58,822 25,457 — 84,279 Equity in earnings of affiliates 1,797 1,839 296 (2,518 ) 1,414 Net gain (loss) on dispositions — (9 ) 19 — 10 Other income — 42 32 — 74 Intercompany revenues — 864 9,160 (10,024 ) — Total Revenues and Other Income 1,797 61,558 34,964 (12,542 ) 85,777 Costs and Expenses Purchased crude oil and products — 48,171 24,102 (9,805 ) 62,468 Operating expenses — 3,465 846 (36 ) 4,275 Selling, general and administrative expenses 6 1,236 406 (10 ) 1,638 Depreciation and amortization — 821 347 — 1,168 Impairments — 1 4 — 5 Taxes other than income taxes — 5,477 8,211 — 13,688 Accretion on discounted liabilities — 16 5 — 21 Interest and debt expense 366 21 124 (173 ) 338 Foreign currency transaction gains — — (15 ) — (15 ) Total Costs and Expenses 372 59,208 34,030 (10,024 ) 83,586 Income before income taxes 1,425 2,350 934 (2,518 ) 2,191 Income tax expense (benefit) (130 ) 553 124 — 547 Net Income 1,555 1,797 810 (2,518 ) 1,644 Less: net income attributable to noncontrolling interests — — 89 — 89 Net Income Attributable to Phillips 66 $ 1,555 1,797 721 (2,518 ) 1,555 Comprehensive Income $ 1,213 1,455 451 (1,817 ) 1,302 Millions of Dollars Year Ended December 31, 2015 Statement of Income Phillips 66 Phillips 66 Company All Other Subsidiaries Consolidating Adjustments Total Consolidated Revenues and Other Income Sales and other operating revenues $ — 68,478 30,497 — 98,975 Equity in earnings (losses) of affiliates 4,470 2,812 (134 ) (5,575 ) 1,573 Net gain (loss) on dispositions — (115 ) 398 — 283 Other income — 81 37 — 118 Intercompany revenues — 1,071 9,845 (10,916 ) — Total Revenues and Other Income 4,470 72,327 40,643 (16,491 ) 100,949 Costs and Expenses Purchased crude oil and products — 54,925 29,221 (10,747 ) 73,399 Operating expenses 4 3,412 917 (39 ) 4,294 Selling, general and administrative expenses 5 1,265 416 (16 ) 1,670 Depreciation and amortization — 818 260 — 1,078 Impairments — 4 3 — 7 Taxes other than income taxes — 5,505 8,572 — 14,077 Accretion on discounted liabilities — 16 5 — 21 Interest and debt expense 365 25 34 (114 ) 310 Foreign currency transaction losses — 1 48 — 49 Total Costs and Expenses 374 65,971 39,476 (10,916 ) 94,905 Income before income taxes 4,096 6,356 1,167 (5,575 ) 6,044 Income tax expense (benefit) (131 ) 1,886 9 — 1,764 Net Income 4,227 4,470 1,158 (5,575 ) 4,280 Less: net income attributable to noncontrolling interests — — 53 — 53 Net Income Attributable to Phillips 66 $ 4,227 4,470 1,105 (5,575 ) 4,227 Comprehensive Income $ 4,105 4,348 1,032 (5,327 ) 4,158
Condensed Consolidated Balance Sheet	Millions of Dollars At December 31, 2017 Balance Sheet Phillips 66 Phillips 66 Company All Other Subsidiaries Consolidating Adjustments Total Consolidated Assets Cash and cash equivalents $ — 1,411 1,708 — 3,119 Accounts and notes receivable 10 5,317 4,476 (2,297 ) 7,506 Inventories — 2,386 1,009 — 3,395 Prepaid expenses and other current assets 2 276 92 — 370 Total Current Assets 12 9,390 7,285 (2,297 ) 14,390 Investments and long-term receivables 32,125 23,483 9,959 (51,626 ) 13,941 Net properties, plants and equipment — 13,117 8,343 — 21,460 Goodwill — 2,853 417 — 3,270 Intangibles — 722 154 — 876 Other assets 12 266 158 (2 ) 434 Total Assets $ 32,149 49,831 26,316 (53,925 ) 54,371 Liabilities and Equity Accounts payable $ — 7,272 3,052 (2,297 ) 8,027 Short-term debt — 9 32 — 41 Accrued income and other taxes — 451 551 — 1,002 Employee benefit obligations — 513 69 — 582 Other accruals 55 298 102 — 455 Total Current Liabilities 55 8,543 3,806 (2,297 ) 10,107 Long-term debt 6,972 50 3,047 — 10,069 Asset retirement obligations and accrued environmental costs — 467 174 — 641 Deferred income taxes — 3,349 1,661 (2 ) 5,008 Employee benefit obligations — 639 245 — 884 Other liabilities and deferred credits 8 4,700 3,814 (8,288 ) 234 Total Liabilities 7,035 17,748 12,747 (10,587 ) 26,943 Common stock 9,396 24,952 10,125 (35,077 ) 9,396 Retained earnings 16,335 7,748 1,306 (9,083 ) 16,306 Accumulated other comprehensive loss (617 ) (617 ) (205 ) 822 (617 ) Noncontrolling interests — — 2,343 — 2,343 Total Liabilities and Equity $ 32,149 49,831 26,316 (53,925 ) 54,371 Millions of Dollars At December 31, 2016 Balance Sheet Phillips 66 Phillips 66 Company All Other Subsidiaries Consolidating Adjustments Total Consolidated Assets Cash and cash equivalents $ — 854 1,857 — 2,711 Accounts and notes receivable 13 4,336 3,276 (1,228 ) 6,397 Inventories — 2,198 952 — 3,150 Prepaid expenses and other current assets 2 317 103 — 422 Total Current Assets 15 7,705 6,188 (1,228 ) 12,680 Investments and long-term receivables 31,165 22,733 8,588 (48,952 ) 13,534 Net properties, plants and equipment — 13,044 7,811 — 20,855 Goodwill — 2,853 417 — 3,270 Intangibles — 719 169 — 888 Other assets 15 245 168 (2 ) 426 Total Assets $ 31,195 47,299 23,341 (50,182 ) 51,653 Liabilities and Equity Accounts payable $ — 5,626 2,663 (1,228 ) 7,061 Short-term debt 500 30 20 — 550 Accrued income and other taxes — 348 457 — 805 Employee benefit obligations — 475 52 — 527 Other accruals 59 371 90 — 520 Total Current Liabilities 559 6,850 3,282 (1,228 ) 9,463 Long-term debt 6,920 150 2,518 — 9,588 Asset retirement obligations and accrued environmental costs — 501 154 — 655 Deferred income taxes — 4,391 2,354 (2 ) 6,743 Employee benefit obligations — 948 268 — 1,216 Other liabilities and deferred credits 1,297 3,337 4,060 (8,431 ) 263 Total Liabilities 8,776 16,177 12,636 (9,661 ) 27,928 Common stock 10,777 25,403 10,117 (35,520 ) 10,777 Retained earnings 12,637 6,714 (269 ) (6,474 ) 12,608 Accumulated other comprehensive loss (995 ) (995 ) (478 ) 1,473 (995 ) Noncontrolling interests — — 1,335 — 1,335 Total Liabilities and Equity $ 31,195 47,299 23,341 (50,182 ) 51,653
Condensed Consolidated Cash Flow	Millions of Dollars Year Ended December 31, 2017 Statement of Cash Flows Phillips 66 Phillips 66 Company All Other Subsidiaries Consolidating Adjustments Total Consolidated Cash Flows From Operating Activities Net Cash Provided by Operating Activities $ 2,619 2,702 1,747 (3,420 ) 3,648 Cash Flows From Investing Activities Capital expenditures and investments* — (1,133 ) (839 ) 140 (1,832 ) Proceeds from asset dispositions** — 265 84 (263 ) 86 Intercompany lending activities 401 1,453 (1,854 ) — — Advances/loans—related parties — (10 ) — — (10 ) Collection of advances/loans—related parties — 75 251 — 326 Restricted cash received from consolidation of business — — 318 — 318 Other — (26 ) (8 ) — (34 ) Net Cash Provided by (Used in) Investing Activities 401 624 (2,048 ) (123 ) (1,146 ) Cash Flows From Financing Activities Issuance of debt 1,500 — 2,008 — 3,508 Repayment of debt (1,500 ) (17 ) (2,161 ) — (3,678 ) Issuance of common stock 35 — — — 35 Repurchase of common stock (1,590 ) — — — (1,590 ) Dividends paid on common stock (1,395 ) (2,752 ) (668 ) 3,420 (1,395 ) Distributions to noncontrolling interests — — (120 ) — (120 ) Net proceeds from issuance of Phillips 66 Partners LP common and preferred units — — 1,205 — 1,205 Other* (70 ) — (129 ) 123 (76 ) Net Cash Provided by (Used in) Financing Activities (3,020 ) (2,769 ) 135 3,543 (2,111 ) Effect of Exchange Rate Changes on Cash, Cash Equivalents and Restricted Cash — — 17 — 17 Net Change in Cash, Cash Equivalents and Restricted Cash — 557 (149 ) — 408 Cash, cash equivalents and restricted cash at beginning of period — 854 1,857 — 2,711 Cash, Cash Equivalents and Restricted Cash at End of Period $ — 1,411 1,708 — 3,119 * Includes intercompany capital contributions. ** Includes return of investments in equity affiliates. Millions of Dollars Year Ended December 31, 2016 Statement of Cash Flows Phillips 66 Phillips 66 Company All Other Subsidiaries* Consolidating Adjustments Total Consolidated Cash Flows From Operating Activities Net Cash Provided by Operating Activities $ 3,491 2,307 1,552 (4,387 ) 2,963 Cash Flows From Investing Activities Capital expenditures and investments** — (1,425 ) (1,457 ) 38 (2,844 ) Proceeds from asset dispositions*** — 1,007 156 (1,007 ) 156 Intercompany lending activities (1,139 ) 2,046 (907 ) — — Advances/loans—related parties — (75 ) (357 ) — (432 ) Collection of advances/loans—related parties — — 108 — 108 Other — 18 (164 ) — (146 ) Net Cash Provided by (Used in) Investing Activities (1,139 ) 1,571 (2,621 ) (969 ) (3,158 ) Cash Flows From Financing Activities Issuance of debt — — 2,090 — 2,090 Repayment of debt — (26 ) (807 ) — (833 ) Issuance of common stock 34 — — — 34 Repurchase of common stock (1,042 ) — — — (1,042 ) Dividends paid on common stock (1,282 ) (3,604 ) (783 ) 4,387 (1,282 ) Distributions to noncontrolling interests — — (75 ) — (75 ) Net proceeds from issuance of Phillips 66 Partners LP common units — — 972 — 972 Other** (62 ) 31 (980 ) 969 (42 ) Net Cash Provided by (Used in) Financing Activities (2,352 ) (3,599 ) 417 5,356 (178 ) Effect of Exchange Rate Changes on Cash, Cash Equivalents and Restricted Cash — — 10 — 10 Net Change in Cash, Cash Equivalents and Restricted Cash — 279 (642 ) — (363 ) Cash, cash equivalents and restricted cash at beginning of period — 575 2,499 — 3,074 Cash, Cash Equivalents and Restricted Cash at End of Period $ — 854 1,857 — 2,711 * Revised to eliminate a purchase and sale transaction between two entities consolidated within the column. This revision increased net cash provided by operating activities by $1,049 million, with an offsetting decrease of $1,049 million in net cash provided by financing activities. The revision did not impact any issuer or guarantor column, nor did it impact our consolidated cash flows. ** Includes intercompany capital contributions. *** Includes return of investments in equity affiliates. Millions of Dollars Year Ended December 31, 2015 Statement of Cash Flows Phillips 66 Phillips 66 Company All Other Subsidiaries Consolidating Adjustments Total Consolidated Cash Flows From Operating Activities Net Cash Provided by Operating Activities $ 1,060 4,879 2,564 (2,790 ) 5,713 Cash Flows From Investing Activities Capital expenditures and investments* — (2,815 ) (5,283 ) 2,334 (5,764 ) Proceeds from asset dispositions** — 774 178 (882 ) 70 Intercompany lending activities 2,461 (3,153 ) 692 — — Advances/loans—related parties — (50 ) — — (50 ) Collection of advances/loans—related parties — 50 — — 50 Other — 6 (50 ) — (44 ) Net Cash Provided by (Used in) Investing Activities 2,461 (5,188 ) (4,463 ) 1,452 (5,738 ) Cash Flows From Financing Activities Issuance of debt — — 1,169 — 1,169 Repayment of debt (800 ) (23 ) (103 ) — (926 ) Issuance of common stock 31 — — — 31 Repurchase of common stock (1,512 ) — — — (1,512 ) Dividends paid on common stock (1,172 ) (1,172 ) (1,576 ) 2,748 (1,172 ) Distributions to controlling interests — — (186 ) 186 — Distributions to noncontrolling interests — — (46 ) — (46 ) Net proceeds from issuance of Phillips 66 Partners LP common units — — 384 — 384 Other* (68 ) 34 1,585 (1,596 ) (45 ) Net Cash Provided by (Used in) Financing Activities (3,521 ) (1,161 ) 1,227 1,338 (2,117 ) Effect of Exchange Rate Changes on Cash, Cash Equivalents and Restricted Cash — — 9 — 9 Net Change in Cash, Cash Equivalents and Restricted Cash — (1,470 ) (663 ) — (2,133 ) Cash, cash equivalents and restricted cash at beginning of period — 2,045 3,162 — 5,207 Cash, Cash Equivalents and Restricted Cash at End of Period $ — 575 2,499 — 3,074 * Includes intercompany capital contributions. ** Includes return of investments in equity affiliates.

Selected Quarterly Financial 61

Selected Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2017
Selected Quarterly Financial Information [Abstract]
Selected Quarterly Financial Data (Unaudited)	Millions of Dollars Per Share of Common Stock Sales and Other Operating Revenues* Income Before Income Taxes Net Income Net Income Attributable to Phillips 66 Net Income Attributable to Phillips 66 Basic Diluted 2017 First $ 22,894 797 563 535 1.02 1.02 Second 24,087 848 581 550 1.06 1.06 Third 25,627 1,256 849 823 1.60 1.60 Fourth** 29,746 654 3,255 3,198 6.29 6.25 2016 First $ 17,409 596 398 385 0.72 0.72 Second 21,849 720 516 496 0.94 0.93 Third 21,624 813 536 511 0.97 0.96 Fourth 23,397 62 194 163 0.31 0.31 * Includes excise taxes on sales of petroleum products. ** Includes a $2,721 million provisional income tax benefit from the enactment of the U.S. Tax Cuts and Jobs Act on December 22, 2017.

Summary of Significant Accoun62

Summary of Significant Accounting Policies (Details)	12 Months Ended
	Dec. 31, 2017reporting_unit	Dec. 31, 2009
Summary of Significant Accounting Policies [Line Items]
Number of reporting units for purposes of testing goodwill for impairment	3
Minimum time required for an award not to be subject to forfeiture	6 years
Minimum
Summary of Significant Accounting Policies [Line Items]
Length of construction period for interest capitalization	1 year
Performance Shares
Summary of Significant Accounting Policies [Line Items]
Eligible retirement age	55
Years of service	5 years	5 years

Variable Interest Entities (Sig

Variable Interest Entities (Significant Liabilities) (Details) - Phillips 66 Partners - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Cash and cash equivalents
Variable Interest Entity [Line Items]
Cash and cash equivalents	$ 185	$ 2
Equity investments
Variable Interest Entity [Line Items]
Noncurrent assets	1,932	1,142
Net properties, plants and equipment
Variable Interest Entity [Line Items]
Noncurrent assets	2,918	2,675
Long-term debt
Variable Interest Entity [Line Items]
Long-term debt	$ 2,920	$ 2,396

Variable Interest Entities (Nar

Variable Interest Entities (Narrative) (Details)	Feb. 07, 2017	Dec. 31, 2017	Aug. 31, 2009	Aug. 28, 2009
Merey Sweeny L.P.
Variable Interest Entities (VIEs) (Textual) [Abstract]
Additional equity method ownership interest acquired in Merey Sweeny Limited Partnership, percent			50.00%	50.00%
Merey Sweeny L.P. | MSLP 8.85% Senior Notes | Guarantees of Joint Venture Debt
Variable Interest Entities (VIEs) (Textual) [Abstract]
Debt guarantee to lender, percent	100.00%
Stated interest rate of debt, percent	8.85%
DAPL
Variable Interest Entities (VIEs) (Textual) [Abstract]
Percentage of ownership interest		25.00%
ETCOP
Variable Interest Entities (VIEs) (Textual) [Abstract]
Percentage of ownership interest		25.00%

Inventories (Summary of Invento

Inventories (Summary of Inventory) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Summary of inventories
Crude oil and petroleum products	$ 3,106	$ 2,883
Materials and supplies	289	267
Inventories	$ 3,395	$ 3,150

Inventories (Narrative) (Detail

Inventories (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Total LIFO inventories	$ 2,980	$ 2,772
Estimated excess of current replacement cost over LIFO cost of inventories	4,300	3,300
Effect on net income due to LIFO inventory liquidation	$ 13	(68)	$ (37)
Whitegate Refinery | Refining
Segment Reporting Information [Line Items]
Effect on net income due to LIFO inventory liquidation		$ (62)

Business Combinations (Details)

Business Combinations (Details) $ in Millions	Feb. 01, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Nov. 30, 2016USD ($)mi	Aug. 31, 2009	Aug. 28, 2009
Business Acquisition [Line Items]
Gain on consolidation of business			$ 423	$ 0	$ 0
Goodwill			$ 3,270	$ 3,270	$ 3,275
NGL Logistics System
Business Acquisition [Line Items]
PP&E provisionally recorded						$ 183
Length of pipeline | mi						500
Goodwill						$ 3
Merey Sweeny L.P.
Business Acquisition [Line Items]
Additional equity method ownership interest acquired in MSLP, percent							50.00%	50.00%
Gain on consolidation of business		$ 423
Step acquisition, equity interest in acquiree, fair value	$ 145
Restricted cash		318
PP&E provisionally recorded		250
Financial liabilities		238
Settlement adjustment		$ 93

Assets Held for Sale or Sold (D

Assets Held for Sale or Sold (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Sep. 30, 2016	Feb. 28, 2015
Refining | Bantry Bay Terminal
Assets Held For Sale Or Sold (Textual) [Abstract]
Net carrying value at time of disposition			$ 68
Marketing and Specialties | Immingham Combined Heat and Power Plant
Assets Held For Sale Or Sold (Textual) [Abstract]
Gain on disposition	$ 242
Whitegate Refinery | Refining
Assets Held For Sale Or Sold (Textual) [Abstract]
Disposal group inventory, other working capital, and properties, plants and equipment		$ 127
Allocated goodwill included in carrying value of disposed asset		8
Net carrying value at time of disposition		$ 135

Investments, Loans and Long-T69

Investments, Loans and Long-Term Receivables (Summary of Components of Investments, Loans, and Long-Term Receivables) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Equity Method Investments and Joint Ventures [Abstract]
Equity investments	$ 13,733	$ 13,102
Loans and long-term receivables	94	334
Other investments	114	98
Total	$ 13,941	$ 13,534

Investments, Loans and Long-T70

Investments, Loans and Long-Term Receivables (Narrative) (Details)	3 Months Ended	12 Months Ended
	Mar. 31, 2017USD ($)	Dec. 31, 2017USD ($)assetjoint_venture	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Sep. 30, 2016USD ($)	Aug. 31, 2016USD ($)	May 31, 2016USD ($)
Schedule of Equity Method Investments [Line Items]
Retained earnings related to undistributed earnings of affiliated companies		$ 2,320,000,000
Dividends received from affiliates		1,270,000,000	$ 616,000,000	$ 1,769,000,000
Equity investments		13,733,000,000	13,102,000,000
Collection of advances/loans—related parties		$ 326,000,000	108,000,000	50,000,000
WRB Refining LP
Schedule of Equity Method Investments [Line Items]
Percentage of ownership interest		50.00%
Amortization period for basis difference of assets contributed to WRB, years		26 years
Equity investments		$ 2,269,000,000
Equity investments, basis difference		2,787,000,000
Equity investment, amortization of basis difference		$ 186,000,000	185,000,000	218,000,000
Collection of advances/loans—related parties	$ 75,000,000
WRB Refining LP | Refining Facilities
Schedule of Equity Method Investments [Line Items]
Number of assets contributed | asset		2
DCP Midstream
Schedule of Equity Method Investments [Line Items]
Percentage of ownership interest		50.00%
Equity investments		$ 2,227,000,000
Equity investments, basis difference		$ 54,000,000
Cash contribution				$ 1,500,000,000
CP Chem
Schedule of Equity Method Investments [Line Items]
Percentage of ownership interest		50.00%
Equity investments		$ 6,222,000,000
CP Chem | Minimum
Schedule of Equity Method Investments [Line Items]
Supply and purchase agreements, initial term		1 year
CP Chem | Maximum
Schedule of Equity Method Investments [Line Items]
Supply and purchase agreements, initial term		99 years
Rockies Express Pipeline LLC (REX)
Schedule of Equity Method Investments [Line Items]
Percentage of ownership interest		25.00%		25.00%
Equity investments		$ 445,000,000
Equity investments, basis difference		$ 376,000,000
Cash contribution				$ 112,000,000
Amount of debt repaid by REX				$ 450,000,000
DCP Sand Hills Pipeline, LLC
Schedule of Equity Method Investments [Line Items]
Percentage of ownership interest		33.00%
Equity investments		$ 515,000,000
DCP Southern Hills Pipeline, LLC
Schedule of Equity Method Investments [Line Items]
Percentage of ownership interest		33.00%
Equity investments		$ 209,000,000
Equity investments, basis difference		94,000,000
Dakota Access LLC and Energy Transfer Crude Oil Company, LLC [Member]
Schedule of Equity Method Investments [Line Items]
Equity investments		621,000,000
Equity investments, basis difference		$ 53,000,000
Equity method investment, line of credit, maximum borrowing capacity						$ 2,500,000,000
DAPL And ETCOP
Schedule of Equity Method Investments [Line Items]
Number of joint ventures | joint_venture		2
DAPL
Schedule of Equity Method Investments [Line Items]
Percentage of ownership interest		25.00%
Equity method investment, maximum borrowing capacity					$ 1,411,000,000		$ 2,256,000,000
Contribution obligation by co-venturer			976,000,000
Equity method investment, borrowing outstanding		$ 244,000,000
ETCOP
Schedule of Equity Method Investments [Line Items]
Percentage of ownership interest		25.00%
Equity method investment, maximum borrowing capacity					$ 76,000,000		$ 227,000,000
Contribution obligation by co-venturer			$ 22,000,000
Equity method investment, borrowing outstanding		$ 6,000,000

Investments, Loans and Long-T71

Investments, Loans and Long-Term Receivables (Summary of Financial Information for Equity Method Investments) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Summary of financial information
Revenues	$ 35,523	$ 30,605	$ 33,126
Income before income taxes	3,956	3,206	3,180
Net income	3,764	2,960	3,158
Current assets	7,325	7,097	6,024
Noncurrent assets	49,950	50,163	46,047
Current liabilities	5,248	5,173	4,130
Noncurrent liabilities	13,743	13,709	11,493
Noncontrolling interests	$ 2,549	$ 2,260	$ 2,404

Properties, Plants and Equipm72

Properties, Plants and Equipment (Narrative) (Details)	12 Months Ended
	Dec. 31, 2017
Refining Facilities
Property, Plant and Equipment [Line Items]
Useful life	25 years
Pipeline Assets
Property, Plant and Equipment [Line Items]
Useful life	45 years
Terminal Assets
Property, Plant and Equipment [Line Items]
Useful life	33 years

Properties, Plants and Equipm73

Properties, Plants and Equipment (By Segment) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Properties, plants and equipment with the associated accumulated depreciation and amortization
Gross PP&E	$ 33,742	$ 31,989
Accum. D&A	12,282	11,134
Net PP&E	21,460	20,855
Midstream
Properties, plants and equipment with the associated accumulated depreciation and amortization
Gross PP&E	8,849	8,179
Accum. D&A	1,853	1,579
Net PP&E	6,996	6,600
Refining
Properties, plants and equipment with the associated accumulated depreciation and amortization
Gross PP&E	22,144	21,152
Accum. D&A	8,987	8,197
Net PP&E	13,157	12,955
Marketing and Specialties
Properties, plants and equipment with the associated accumulated depreciation and amortization
Gross PP&E	1,658	1,451
Accum. D&A	909	776
Net PP&E	749	675
Corporate and Other
Properties, plants and equipment with the associated accumulated depreciation and amortization
Gross PP&E	1,091	1,207
Accum. D&A	533	582
Net PP&E	$ 558	$ 625

Goodwill and Intangibles (Goodw

Goodwill and Intangibles (Goodwill) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Goodwill [Line Items]
Indefinite-lived intangible assets	$ 756	$ 764
Net amortized intangible asset balance	120	124
Accumulated amortization	173	152
Amortization of Intangible Assets	21	18	$ 13
Estimated future amortization expense (less than)	20
Goodwill [Roll Forward]
Balance at January 1	3,270	3,275
Goodwill assigned to acquisitions		3
Goodwill allocated to dispositions		(8)
Goodwill, Adjustments	0
Balance at December 31	3,270	3,270	3,275
Midstream
Goodwill [Roll Forward]
Balance at January 1	626	623
Goodwill assigned to acquisitions		3
Goodwill, Adjustments	0
Balance at December 31	626	626	623
Refining
Goodwill [Roll Forward]
Balance at January 1	1,805	1,813
Goodwill allocated to dispositions		(8)
Goodwill, Adjustments	0
Balance at December 31	1,805	1,805	1,813
Marketing and Specialties
Goodwill [Roll Forward]
Balance at January 1	839	839
Goodwill, Adjustments	0
Balance at December 31	$ 839	$ 839	$ 839

Goodwill and Intangibles (Intan

Goodwill and Intangibles (Intangible Assets) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Indefinite-lived Intangible Assets [Line Items]
Indefinite-lived intangible assets	$ 756	$ 764
Net amortized intangible asset balance	120	124
Accumulated amortization	173	152
Amortization of Intangible Assets	21	18	$ 13
Estimated future amortization expense (less than)	20
Trade names and trademarks
Indefinite-lived Intangible Assets [Line Items]
Indefinite-lived intangible assets	503	503
Refinery air and operating permits
Indefinite-lived Intangible Assets [Line Items]
Indefinite-lived intangible assets	252	260
Other
Indefinite-lived Intangible Assets [Line Items]
Indefinite-lived intangible assets	$ 1	$ 1

Asset Retirement Obligations 76

Asset Retirement Obligations and Accrued Environmental Costs (Summary of Asset Retirement Obligations and Accrued Environmental Costs) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Asset Retirement Obligation and Accrual for Environmental Cost Disclosure [Abstract]
Asset retirement obligations	$ 268	$ 244	$ 251
Accrued environmental costs	458	496
Total asset retirement obligations and accrued environmental costs	726	740
Asset retirement obligations and accrued environmental costs due within one year	(85)	(85)
Long-term asset retirement obligations and accrued environmental costs	$ 641	$ 655

Asset Retirement Obligations 77

Asset Retirement Obligations and Accrued Environmental Costs (Schedule of Change in Overall Asset Retirement Obligation) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Asset Retirement Obligation, Roll Forward Analysis [Roll Forward]
Balance at January 1	$ 244	$ 251
Accretion of discount	10	9
Changes in estimates of existing obligations	17	10
Spending on existing obligations	(14)	(15)
Property dispositions	0	(5)
Foreign currency translation	11	(6)
Balance at December 31	$ 268	$ 244

Asset Retirement Obligations 78

Asset Retirement Obligations and Accrued Environmental Costs (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Site Contingency [Line Items]
Decrease in total accrued environmental	$ 38
Accrued environmental costs	458	$ 496
Domestic Refineries and Underground Sites [Member]
Site Contingency [Line Items]
Total accrued environmental	222
Nonoperator sites
Site Contingency [Line Items]
Total accrued environmental	187
Other sites
Site Contingency [Line Items]
Total accrued environmental	49
Acquired through Business Combination
Site Contingency [Line Items]
Accrued environmental costs	268
Expected future undiscounted payments related to the portion of the accrued environmental costs that have been discounted
Expected future undiscounted payments, due in 2018	18
Expected future undiscounted payments, due in 2019	46
Expected future undiscounted payments, due in 2020	30
Expected future undiscounted payments, due in 2021	16
Expected future undiscounted payments, due in 2022	16
Expected future undiscounted payments, due for all future years after 2022	$ 216
Weighted Average | Acquired through Business Combination
Site Contingency [Line Items]
Accrued environmental costs, discount rate, percent	5.00%

Earnings per Share (Details)

Earnings per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Basic
Net income attributable to Phillips 66									$ 5,106	$ 1,555	$ 4,227
Income allocated to participating securities									(6)	(6)	(6)
Net income available to common stockholders									$ 5,100	$ 1,549	$ 4,221
Weighted-average common shares outstanding (in shares)									511,268	523,250	537,602
Effect of share-based compensation (in shares)									3,822	4,281	4,753
Weighted-average commons shares outstanding - basic (in shares)									515,090	527,531	542,355
Net Income Attributable to Phillips 66 Per Share of Common Stock (in dollars per share)	$ 6.29	$ 1.60	$ 1.06	$ 1.02	$ 0.31	$ 0.97	$ 0.94	$ 0.72	$ 9.90	$ 2.94	$ 7.78
Diluted
Net income attributable to Phillips 66									$ 5,106	$ 1,555	$ 4,227
Income allocated to participating securities									0	(5)	0
Net income available to common stockholders									$ 5,106	$ 1,550	$ 4,227
Weighted-average commons shares outstanding - basic (in shares)									515,090	527,531	542,355
Effect of share-based compensation (in shares)									3,418	2,535	4,622
Weighted-average common shares outstanding—EPS (in shares)									518,508	530,066	546,977
Net Income Attributable to Phillips 66 Per Share of Common Stock (in dollars per share)	$ 6.25	$ 1.60	$ 1.06	$ 1.02	$ 0.31	$ 0.96	$ 0.93	$ 0.72	$ 9.85	$ 2.92	$ 7.73

Debt (Summary of Long-Term Debt

Debt (Summary of Long-Term Debt) (Details) - USD ($) $ in Millions	Dec. 31, 2017	May 31, 2017	Dec. 31, 2016
Summary of long term debt
Debt at face value	$ 10,026		$ 10,054
Capitalized leases	192		188
Net unamortized discounts and debt issuance costs	(108)		(104)
Total debt	10,110		10,138
Short-term debt	(41)		(550)
Long-term debt	10,069		9,588
Floating-rate notes due 2019 at 2.009% at year-end 2017
Summary of long term debt
Debt	$ 300
Percentage bearing variable interest	2.01%
Floating-rate notes due 2020 at 2.109% at year-end 2017
Summary of long term debt
Debt	$ 300
Percentage bearing variable interest	2.11%
Term loan due 2020 at 2.469% at year-end 2017
Summary of long term debt
Debt	$ 450
Stated interest rate of debt, percent	2.469%
Note payable to MSLP due 2020 at 7%
Summary of long term debt
Note payable to MSLP due 2020 at 7.00%			68
Stated interest rate of debt, percent	7.00%
Industrial Development Bonds due 2018 through 2021 at 0.80%-2.09% at year-end 2017 and 0.57%-0.81% at year-end 2016
Summary of long term debt
Debt	$ 100		$ 50
Industrial Development Bonds due 2018 through 2021 at 0.80%-2.09% at year-end 2017 and 0.57%-0.81% at year-end 2016 | Minimum
Summary of long term debt
Stated interest rate of debt, percent	0.80%		0.57%
Industrial Development Bonds due 2018 through 2021 at 0.80%-2.09% at year-end 2017 and 0.57%-0.81% at year-end 2016 | Maximum
Summary of long term debt
Stated interest rate of debt, percent	2.09%		0.81%
Phillips 66 Partners revolving credit facility due 2021 at 1.98% at year-end 2016
Summary of long term debt
Phillips 66 Partners revolving credit facility due 2021 at 1.98% at year-end 2016			$ 210
Stated interest rate of debt, percent			1.98%
Other
Summary of long term debt
Debt	$ 1		$ 1
Senior Notes | 2.950% Senior Notes due 2017
Summary of long term debt
Debt			1,500
Stated interest rate of debt, percent	2.95%	2.95%
Senior Notes | 4.300% Senior Notes due 2022
Summary of long term debt
Debt	$ 2,000		2,000
Stated interest rate of debt, percent	4.30%
Senior Notes | 4.650% Senior Notes due 2034
Summary of long term debt
Debt	$ 1,000		1,000
Stated interest rate of debt, percent	4.65%
Senior Notes | 5.875% Senior Notes due 2042
Summary of long term debt
Debt	$ 1,500		1,500
Stated interest rate of debt, percent	5.875%
Senior Notes | 4.875% Senior Notes due 2044
Summary of long term debt
Debt	$ 1,500		1,500
Stated interest rate of debt, percent	4.875%
Senior Notes | Phillips 66 Partners LP | Phillips 66 Partners 2.646% Senior Notes due 2020
Summary of long term debt
Debt	$ 300		300
Stated interest rate of debt, percent	2.646%
Senior Notes | Phillips 66 Partners LP | Phillips 66 Partners 3.605% Senior Notes due 2025
Summary of long term debt
Debt	$ 500		500
Stated interest rate of debt, percent	3.605%
Senior Notes | Phillips 66 Partners LP | Phillips 66 Partners 3.550% Senior Notes due 2026
Summary of long term debt
Debt	$ 500		500
Stated interest rate of debt, percent	3.55%
Senior Notes | Phillips 66 Partners LP | Phillips 66 Partners 3.750% Senior Notes due 2028
Summary of long term debt
Debt	$ 500
Stated interest rate of debt, percent	3.75%
Senior Notes | Phillips 66 Partners LP | Phillips 66 Partners 4.680% Senior Notes due 2045
Summary of long term debt
Debt	$ 450		300
Stated interest rate of debt, percent	4.68%
Senior Notes | Phillips 66 Partners LP | Phillips 66 Partners 4.900% Senior Notes due 2046
Summary of long term debt
Debt	$ 625		$ 625
Stated interest rate of debt, percent	4.90%

Debt (Narrative) (Details)

Debt (Narrative) (Details) - USD ($)	1 Months Ended		12 Months Ended
	May 31, 2017	Apr. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Oct. 31, 2017	Feb. 28, 2017
Long-term Debt, Fiscal Year Maturity [Abstract]
Long-term borrowing maturities, 2018			$ 41,000,000
Long-term borrowing maturities, 2019			314,000,000
Long-term borrowing maturities, 2020			1,084,000,000
Long-term borrowing maturities, 2021			62,000,000
Long-term borrowing maturities, 2022			2,003,000,000
Repayment of debt			3,678,000,000	$ 833,000,000	$ 926,000,000
Borrowings under commercial paper program			0
Revolving Credit Facility
Long-term Debt, Fiscal Year Maturity [Abstract]
Maximum borrowing capacity			5,000,000,000
Amount outstanding under facility			0
Phillips 66 Partners LP | Revolving Credit Facility
Long-term Debt, Fiscal Year Maturity [Abstract]
Maximum borrowing capacity			750,000,000
Phillips 66 Partners LP | Phillips 66 Partners | Senior Notes
Long-term Debt, Fiscal Year Maturity [Abstract]
Senior notes						$ 650,000,000
Phillips 66 Partners LP | Phillips 66 Partners | Loans Payable
Long-term Debt, Fiscal Year Maturity [Abstract]
Senior notes						450,000,000
Loans Payable
Long-term Debt, Fiscal Year Maturity [Abstract]
Senior notes		$ 900,000,000
Commercial Paper
Long-term Debt, Fiscal Year Maturity [Abstract]
Maximum borrowing capacity			$ 5,000,000,000
Phillips 66 Partners 3.750% Senior Notes due 2028 | Phillips 66 Partners LP | Senior Notes
Long-term Debt, Fiscal Year Maturity [Abstract]
Senior notes, interest percent			3.75%
Phillips 66 Partners 3.750% Senior Notes due 2028 | Phillips 66 Partners LP | Phillips 66 Partners | Senior Notes
Long-term Debt, Fiscal Year Maturity [Abstract]
Senior notes						$ 500,000,000
Senior notes, interest percent						3.75%
Senior Notes due 2045 | Phillips 66 Partners LP | Phillips 66 Partners | Senior Notes
Long-term Debt, Fiscal Year Maturity [Abstract]
Senior notes						$ 150,000,000
Senior notes, interest percent						4.68%
Phillips 66 Partners revolving credit facility due 2021 at 1.98% at year-end 2016
Long-term Debt, Fiscal Year Maturity [Abstract]
Senior notes, interest percent				1.98%
Amount outstanding under facility				$ 210,000,000
Phillips 66 Partners revolving credit facility due 2021 at 1.98% at year-end 2016 | Revolving Credit Facility
Long-term Debt, Fiscal Year Maturity [Abstract]
Maximum borrowing capacity			$ 750,000,000
Unsecured Notes | Unsecured Debt
Long-term Debt, Fiscal Year Maturity [Abstract]
Senior notes		600,000,000
Notes due 2019 | Senior Notes
Long-term Debt, Fiscal Year Maturity [Abstract]
Senior notes							$ 135,000,000
Senior notes, interest percent							8.85%
Notes due 2019 | Unsecured Debt
Long-term Debt, Fiscal Year Maturity [Abstract]
Senior notes		300,000,000
Notes due 2020 | Unsecured Debt
Long-term Debt, Fiscal Year Maturity [Abstract]
Senior notes		$ 300,000,000
Term Loan Due, 364-day facility | Loans Payable
Long-term Debt, Fiscal Year Maturity [Abstract]
Number of days maturities are generally limited to		364 days
Term Loan Due, 364-day facility | Loans Payable
Long-term Debt, Fiscal Year Maturity [Abstract]
Senior notes		$ 450,000,000
Term Loan Due, three-year facility | Loans Payable
Long-term Debt, Fiscal Year Maturity [Abstract]
Senior notes		$ 450,000,000
Number of days maturities are generally limited to		3 years
2.950% Senior Notes due 2017 | Senior Notes
Long-term Debt, Fiscal Year Maturity [Abstract]
Senior notes, interest percent	2.95%		2.95%
Repayment of debt	$ 1,500,000,000
Note payable to MSLP due 2020 at 7% (related party) | Tax-Exempt Bonds
Long-term Debt, Fiscal Year Maturity [Abstract]
Senior notes							$ 100,000,000
Senior Notes due in 2019 | Senior Notes
Long-term Debt, Fiscal Year Maturity [Abstract]
Senior notes, interest percent	8.85%
Repayment of debt	$ 135,000,000
Maximum
Long-term Debt, Fiscal Year Maturity [Abstract]
Maximum consolidated net debt-to-capitalization ratio, percent			0.6
Maximum | Commercial Paper
Long-term Debt, Fiscal Year Maturity [Abstract]
Number of days maturities are generally limited to			90 days
London Interbank Offered Rate (LIBOR) | Notes due 2019 | Unsecured Debt
Long-term Debt, Fiscal Year Maturity [Abstract]
Basis spread on variable rate		0.65%
London Interbank Offered Rate (LIBOR) | Notes due 2020 | Unsecured Debt
Long-term Debt, Fiscal Year Maturity [Abstract]
Basis spread on variable rate		0.75%

Guarantees (Details)

Guarantees (Details) - USD ($) $ in Millions	1 Months Ended	12 Months Ended
	Oct. 31, 2017	Dec. 31, 2017	Dec. 31, 2016
Guarantor Obligations [Line Items]
Operating lease, remaining obligation		$ 1,826
Environmental accruals for known contaminations		458	$ 496
Indemnifications
Guarantor Obligations [Line Items]
Carrying amount of indemnifications		193
Asset Retirement Obligations And Accrued Environmental Cost | Indemnifications
Guarantor Obligations [Line Items]
Environmental accruals for known contaminations		104
DCP Midstream | Other Guarantees
Guarantor Obligations [Line Items]
Maximum exposure of loss/potential amount of future payments		$ 175
Other Joint Ventures
Guarantor Obligations [Line Items]
Guarantor obligations, term		P8Y
Other Joint Ventures | Other Guarantees
Guarantor Obligations [Line Items]
Maximum exposure of loss/potential amount of future payments		$ 133
Facilities | Residual Value Guarantees
Guarantor Obligations [Line Items]
Maximum exposure of loss/potential amount of future payments			$ 554
Facilities | Maximum | Other Guarantees
Guarantor Obligations [Line Items]
Lessee leasing arrangements, operating leases			5 years
Railcar and Airplane | Residual Value Guarantees
Guarantor Obligations [Line Items]
Maximum exposure of loss/potential amount of future payments		305
Railcars | Residual Value Guarantees
Guarantor Obligations [Line Items]
Maximum exposure of loss/potential amount of future payments			$ 109
Operating leases, expense		45	$ 28
Settled amount	$ 53
Railcars | Residual Value Guarantees
Guarantor Obligations [Line Items]
Operating lease, remaining obligation		$ 36

Contingencies and Commitments (

Contingencies and Commitments (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Contingencies and Commitments (Textual) [Abstract]
Aggregate amounts of estimated payments under long-term throughput and take-or-pay agreements - 2018	$ 327
Aggregate amounts of estimated payments under long-term throughput and take-or-pay agreements - 2019	327
Aggregate amounts of estimated payments under long-term throughput and take-or-pay agreements - 2020	327
Aggregate amounts of estimated payments under long-term throughput and take-or-pay agreements - 2021	327
Aggregate amounts of estimated payments under long-term throughput and take-or-pay agreements - 2022	327
Aggregate amounts of estimated payments under long-term throughput and take-or-pay agreements - 2023 and after	2,644
Total payments under long-term throughput and take-or-pay agreements	323	$ 325	$ 328
Performance Guarantee
Contingencies and Commitments (Textual) [Abstract]
Performance obligations secured by letters of credit and bank guarantees	$ 773

Derivatives and Financial Ins84

Derivatives and Financial Instruments (Summary of Commodity Derivative Assets and Liabilities) (Details) - Not Designated as Hedging Instrument - Commodity Derivatives - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Liabilities
Effect of Collateral Netting	$ 21	$ 73
Total
Assets	749	746
Liabilities	(769)	(768)
Net Carrying Value Presented on the Balance Sheet	1	51
Prepaid expenses and other current assets
Assets
Assets	43	267
Liabilities	(19)	(154)
Effect of Collateral Netting	0	0
Net Carrying Value Presented on the Balance Sheet	24	113
Other assets
Assets
Assets	7	5
Liabilities	(3)	(1)
Effect of Collateral Netting	0	0
Net Carrying Value Presented on the Balance Sheet	4	4
Other accruals
Liabilities
Assets	699	474
Liabilities	(746)	(612)
Effect of Collateral Netting	21	73
Net Carrying Value Presented on the Balance Sheet	(26)	(65)
Other liabilities and deferred credits
Liabilities
Assets	0	0
Liabilities	(1)	(1)
Effect of Collateral Netting	0	0
Net Carrying Value Presented on the Balance Sheet	$ (1)	$ (1)

Derivatives and Financial Ins85

Derivatives and Financial Instruments (Summary of Gains/(Losses) From Commodity Derivatives) (Details) - Commodity derivatives - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Summary of gains (losses) from commodity derivatives
Net gain (loss) from commodity derivative activity	$ (238)	$ (484)	$ 341
Sales and other operating revenues
Summary of gains (losses) from commodity derivatives
Net gain (loss) from commodity derivative activity	(247)	(451)	162
Other income
Summary of gains (losses) from commodity derivatives
Net gain (loss) from commodity derivative activity	27	29	58
Purchased crude oil and products
Summary of gains (losses) from commodity derivatives
Net gain (loss) from commodity derivative activity	$ (18)	$ (62)	$ 121

Derivatives and Financial Ins86

Derivatives and Financial Instruments (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Estimated percentage of derivative contract volume expiring within twelve months	98.00%	98.00%
Payment terms of receivables	30 days or less
Cash Flow Hedging | Interest Rate Swap | Designated as Hedging Instrument
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative, notional amount	$ 650,000,000
Derivative instruments, gain reclassified from AOCI into income in next twelve months	2,000,000
Cash Flow Hedging | Interest Rate Swap | Designated as Hedging Instrument | Other Accruals and Other Assets
Fair Value, Assets and Liabilities Measured on Recurring Basis [Line Items]
Derivative fair value		$ 8,000,000
Derivative, Fair Value, Net	$ 14,000,000	$ 8,000,000

Derivatives and Financial Ins87

Derivatives and Financial Instruments (Summary of Outstanding Commodity Derivative Contracts) (Details) - MMBbls	Dec. 31, 2017	Dec. 31, 2016
Commodity
Crude oil, refined products and NGL (millions of barrels)	(11)	(18)

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Details) $ in Millions	Dec. 31, 2017USD ($)
Fair Value Disclosures [Abstract]
Aggregate value of assets transferred to Level 1	$ 131
Aggregate value of liabilities transferred to Level 1	$ 134

Fair Value Measurements (Summar

Fair Value Measurements (Summary of Fair Value of Derivative Assets and Liabilities and Effect of Counterparty Netting) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Difference in Carrying Value and Fair Value	$ (978)	$ (570)
Fixed-rate debt, excluding capital leases
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Difference in Carrying Value and Fair Value	(978)
Net Carrying Value Presented on the Balance Sheet
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net carrying value presented on balance sheet, commodity derivative assets	14	8
Net carrying value presented on balance sheet, commodity derivative assets and investments	154	222
Net carrying value presented on balance sheet, commodity derivative liabilities and debt	9,945	10,016
Net Carrying Value Presented on the Balance Sheet | Floating-rate debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Floating-rate debt	1,150	260
Net Carrying Value Presented on the Balance Sheet | Fixed-rate debt, excluding capital leases
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fixed-rate debt, excluding capital leases	8,768	9,690
Exchange-cleared instruments | Net Carrying Value Presented on the Balance Sheet
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net carrying value presented on balance sheet, commodity derivative assets	7	16
OTC instruments | Net Carrying Value Presented on the Balance Sheet
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net carrying value presented on balance sheet, commodity derivative assets		5
Physical forward contracts | Net Carrying Value Presented on the Balance Sheet
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Net carrying value presented on balance sheet, commodity derivative assets	21	96
Net carrying value presented on balance sheet, commodity derivative liabilities	27	66
Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Liabilities	(721)	(629)
Interest Rate Cash Flow Hedge Asset at Fair Value	14	8
Total assets, fair value disclosure gross	875	851
Effect of counterparty netting, commodity derivative liabilities	(721)	(629)
Effect of Collateral Netting	(21)	(73)
Total liabilities, fair value disclosure gross	11,665	11,288
Fair Value, Measurements, Recurring | Floating-rate debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt excluding capital leases, fair value gross	1,150	260
Fair Value, Measurements, Recurring | Fixed-rate debt, excluding capital leases
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt excluding capital leases, fair value gross	9,746	10,260
Difference in Carrying Value and Fair Value		(570)
Fair Value, Measurements, Recurring | Exchange-cleared instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity derivative assets, fair value gross	728	644
Liabilities	(721)	(628)
Commodity derivative liabilities, fair value gross	742	701
Effect of counterparty netting, commodity derivative liabilities	(721)	(628)
Effect of Collateral Netting	(21)	(73)
Fair Value, Measurements, Recurring | OTC instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity derivative assets, fair value gross		6
Liabilities		(1)
Commodity derivative liabilities, fair value gross		1
Effect of counterparty netting, commodity derivative liabilities		(1)
Fair Value, Measurements, Recurring | Physical forward contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity derivative assets, fair value gross	21	96
Commodity derivative liabilities, fair value gross	27	66
Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets, fair value disclosure gross	445	370
Total liabilities, fair value disclosure gross	369	249
Fair Value, Measurements, Recurring | Level 1 | Exchange-cleared instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity derivative assets, fair value gross	333	273
Commodity derivative liabilities, fair value gross	369	249
Fair Value, Measurements, Recurring | Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Interest Rate Cash Flow Hedge Asset at Fair Value	14	8
Total assets, fair value disclosure gross	429	479
Total liabilities, fair value disclosure gross	11,292	11,034
Fair Value, Measurements, Recurring | Level 2 | Floating-rate debt
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt excluding capital leases, fair value gross	1,150	260
Fair Value, Measurements, Recurring | Level 2 | Fixed-rate debt, excluding capital leases
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Debt excluding capital leases, fair value gross	9,746	10,260
Fair Value, Measurements, Recurring | Level 2 | Exchange-cleared instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity derivative assets, fair value gross	395	371
Commodity derivative liabilities, fair value gross	373	452
Fair Value, Measurements, Recurring | Level 2 | OTC instruments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity derivative assets, fair value gross		6
Commodity derivative liabilities, fair value gross		1
Fair Value, Measurements, Recurring | Level 2 | Physical forward contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity derivative assets, fair value gross	20	94
Commodity derivative liabilities, fair value gross	23	61
Fair Value, Measurements, Recurring | Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Total assets, fair value disclosure gross	1	2
Total liabilities, fair value disclosure gross	4	5
Fair Value, Measurements, Recurring | Level 3 | Physical forward contracts
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Commodity derivative assets, fair value gross	1	2
Commodity derivative liabilities, fair value gross	4	5
Rabbi trust assets | Net Carrying Value Presented on the Balance Sheet | Equity investments
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Rabbi trust assets	112	97
Rabbi trust assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Rabbi trust assets	112	97
Rabbi trust assets | Fair Value, Measurements, Recurring | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Rabbi trust assets	$ 112	$ 97

Equity (Details)

Equity (Details) - USD ($)	Feb. 07, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2017
Class of Stock [Line Items]
Preferred stock authorized, shares (in shares)		500,000,000				500,000,000
Par value of preferred stock, per share (in dollars per share)		$ 0.01				$ 0.01
Preferred stock outstanding, shares (in shares)		0	0			0
Cost of shares repurchased		$ 1,590,000,000	$ 1,042,000,000	$ 1,512,000,000
Share Repurchase Program And Additional Share Repurchases
Class of Stock [Line Items]
Amount authorized for stock repurchase		$ 12,000,000,000				$ 12,000,000,000
Repurchase of common stock, shares (in shares)						124,142,530
Cost of shares repurchased						$ 9,000,000,000
Subsequent Event
Class of Stock [Line Items]
Quarterly cash dividend declared (in dollars per share)	$ 0.70
Share exchange—PSPI transaction
Class of Stock [Line Items]
Repurchase of common stock, shares (in shares)					17,422,615
Cost of shares repurchased					$ 1,350,000,000

Leases (Narrative) (Details)

Leases (Narrative) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Leases [Abstract]
Total net PP&E recorded for capital leases	$ 210	$ 208

Leases (Summary of Future Minim

Leases (Summary of Future Minimum Lease Payments) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Capital Lease Obligations
2,018	$ 22
2,019	22
2,020	18
2,021	18
2,022	15
Remaining years	148
Total	243
Less: income from subleases	0
Net minimum lease payments	243
Less: amount representing interest	51
Capital lease obligations	192	$ 188
Operating Lease Obligations
2,018	533
2,019	420
2,020	306
2,021	141
2,022	100
Remaining years	326
Total	1,826
Less: income from subleases	71
Net minimum lease payments	$ 1,755

Leases (Summary of Operating Le

Leases (Summary of Operating Lease Rental Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Leases, Rent Expense, Net [Abstract]
Minimum rentals	$ 680	$ 669	$ 641
Contingent rentals	6	6	6
Less: sublease rental income	73	95	136
Total	$ 613	$ 580	$ 511

Pension and Postretirement Pl94

Pension and Postretirement Plans (Reconciliation of Projected Benefit Obligations and Plan Assets) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Pension Benefits | United States
Change in Benefit Obligation
Benefit obligation at January 1	$ 2,881	$ 2,791
Service cost	132	127	$ 124
Interest cost	108	116	109
Actuarial loss (gain)	267	62
Benefits paid	(345)	(215)
Benefit obligation at December 31	3,043	2,881	2,791
Change in Fair Value of Plan Assets
Fair value of plan assets at January 1	2,274	2,023
Actual return on plan assets	399	136
Company contributions	423	330
Benefits paid	(345)	(215)
Fair value of plan assets at December 31	2,751	2,274	2,023
Funded Status at December 31	(292)	(607)
Pension Benefits | Int’l.
Change in Benefit Obligation
Benefit obligation at January 1	1,055	912
Service cost	32	32	38
Interest cost	27	28	28
Plan participant contributions	2	3
Actuarial loss (gain)	(5)	237
Benefits paid	(20)	(19)
Curtailment gain		(31)
Foreign currency exchange rate change	118	(107)
Benefit obligation at December 31	1,209	1,055	912
Change in Fair Value of Plan Assets
Fair value of plan assets at January 1	796	742
Actual return on plan assets	71	148
Company contributions	35	40
Plan participant contributions	2	3
Benefits paid	(20)	(19)
Foreign currency exchange rate change	88	(118)
Fair value of plan assets at December 31	972	796	742
Funded Status at December 31	(237)	(259)
Other Benefits
Change in Benefit Obligation
Benefit obligation at January 1	225	219
Service cost	6	7	7
Interest cost	8	8	7
Plan participant contributions	3	2
Actuarial loss (gain)	6	(6)
Benefits paid	(16)	(13)
Acquisition of a business		8
Benefit obligation at December 31	232	225	$ 219
Change in Fair Value of Plan Assets
Company contributions	13	11
Plan participant contributions	3	2
Benefits paid	(16)	(13)
Funded Status at December 31	$ (232)	$ (225)

Pension and Postretirement Pl95

Pension and Postretirement Plans (Summary of Amounts Recognized in the Consolidated Balance Sheet (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Defined Benefit Plan Disclosure [Line Items]
Noncurrent liabilities	$ (884)	$ (1,216)
Pension Benefits | United States
Defined Benefit Plan Disclosure [Line Items]
Current liabilities	(25)	(10)
Noncurrent liabilities	(267)	(597)
Total recognized	(292)	(607)
Pension Benefits | Int’l.
Defined Benefit Plan Disclosure [Line Items]
Noncurrent liabilities	(237)	(259)
Total recognized	(237)	(259)
Other Benefits
Defined Benefit Plan Disclosure [Line Items]
Current liabilities	(16)	(10)
Noncurrent liabilities	(216)	(215)
Total recognized	$ (232)	$ (225)

Pension and Postretirement Pl96

Pension and Postretirement Plans (Summary of Amounts Recognized in Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Net gain (loss) arising during the period	$ (1)	$ (178)	$ (138)
Curtailment gain	0	31	$ 0
Pension Benefits | United States
Defined Benefit Plan Disclosure [Line Items]
Unrecognized net actuarial loss (gain)	545	684
Unrecognized prior service cost (credit)		3
Net gain (loss) arising during the period	(14)	(54)
Amortization of loss and settlements included in income	153	80
Net change in unrecognized net actuarial loss (gain) during the period	139	26
Amortization of prior service cost (credit) included in income	3	3
Net change in unrecognized prior service cost (credit) during the period	3	3
Pension Benefits | Int’l.
Defined Benefit Plan Disclosure [Line Items]
Unrecognized net actuarial loss (gain)	190	227
Unrecognized prior service cost (credit)	(4)	(5)
Net gain (loss) arising during the period	14	(129)
Curtailment gain		31
Amortization of loss and settlements included in income	23	14
Net change in unrecognized net actuarial loss (gain) during the period	37	(84)
Amortization of prior service cost (credit) included in income	(1)	(1)
Net change in unrecognized prior service cost (credit) during the period	(1)	(1)
Other Benefits
Defined Benefit Plan Disclosure [Line Items]
Unrecognized net actuarial loss (gain)	1	(5)
Unrecognized prior service cost (credit)	(7)	(9)
Net gain (loss) arising during the period	(6)	7
Curtailment gain	0	0
Amortization of loss and settlements included in income	0	0
Net change in unrecognized net actuarial loss (gain) during the period	(6)	7
Amortization of prior service cost (credit) included in income	(2)	(1)
Net change in unrecognized prior service cost (credit) during the period	$ (2)	$ (1)

Pension and Postretirement Pl97

Pension and Postretirement Plans (Accumulated Benefit Obligation in Excess of Plan Assets) (Details) (Details) - Pension Benefits - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
United States
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligations	$ 172	$ 2,881
Accumulated benefit obligations	143	2,601
Fair value of plan assets		2,274
Int’l.
Defined Benefit Plan Disclosure [Line Items]
Projected benefit obligations	389	355
Accumulated benefit obligations	368	334
Fair value of plan assets	$ 196	$ 166

Pension and Postretirement Pl98

Pension and Postretirement Plans (Summary of Components of Net Periodic Benefit Cost) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Pension Benefits | United States
Defined Benefit Plan Disclosure [Line Items]
Service cost	$ 132	$ 127	$ 124
Interest cost	108	116	109
Expected return on plan assets	(146)	(128)	(138)
Amortization of prior service cost (credit)	3	3	3
Recognized net actuarial loss (gain)	70	72	75
Settlements	83	8	80
Total net periodic benefit cost	250	198	253
Pension Benefits | Int’l.
Defined Benefit Plan Disclosure [Line Items]
Service cost	32	32	38
Interest cost	27	28	28
Expected return on plan assets	(40)	(38)	(37)
Amortization of prior service cost (credit)	(1)	(1)	(1)
Recognized net actuarial loss (gain)	23	14	15
Total net periodic benefit cost	41	35	43
Other Benefits
Defined Benefit Plan Disclosure [Line Items]
Service cost	6	7	7
Interest cost	8	8	7
Amortization of prior service cost (credit)	(2)	(1)	(2)
Recognized net actuarial loss (gain)			(1)
Total net periodic benefit cost	$ 12	$ 14	$ 11

Pension and Postretirement Pl99

Pension and Postretirement Plans (Narrative) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Defined Benefit Plan Disclosure [Line Items]
Net actuarial gains and losses, Percent amortized	10.00%
Maximum employee contribution of eligible pay, Percent	75.00%
Semi-annual discretionary company contribution target, Percent	2.00%
Total expense related to participants in the Savings Plan	$ 101	$ 99	$ 134
Equity securities
Defined Benefit Plan Disclosure [Line Items]
Target allocations for plan assets	57.00%
Debt Securities
Defined Benefit Plan Disclosure [Line Items]
Target allocations for plan assets	41.00%
Other Types of Investments
Defined Benefit Plan Disclosure [Line Items]
Target allocations for plan assets	2.00%
Minimum
Defined Benefit Plan Disclosure [Line Items]
Minimum participant contribution to Savings Plan to be eligible for Success Share, Percent	1.00%
Semi-annual discretionary company contribution, Percent	0.00%
Maximum
Defined Benefit Plan Disclosure [Line Items]
Company match of participant's contributions of eligible pay, Percent	5.00%
Semi-annual discretionary company contribution, Percent	6.00%
Other Benefits
Defined Benefit Plan Disclosure [Line Items]
Health care cost trend rate, percentage	6.25%
Health care cost trend rate, ultimate, percentage	5.00%
Pension Benefits | United States
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligations	$ 2,743	2,601
Expected future employer contributions next fiscal year	60
Pension Benefits | Int’l.
Defined Benefit Plan Disclosure [Line Items]
Accumulated benefit obligations	1,006	$ 880
Expected future employer contributions next fiscal year	$ 35

Pension and Postretirement P100

Pension and Postretirement Plans (Summary of Net Periodic Benefit Cost) (Details) $ in Millions	Dec. 31, 2017USD ($)
Pension Benefits | United States
Defined Benefit Plan Disclosure [Line Items]
Unrecognized net actuarial loss	$ 59
Pension Benefits | Int’l.
Defined Benefit Plan Disclosure [Line Items]
Unrecognized net actuarial loss	19
Unrecognized prior service credit	(1)
Other Benefits
Defined Benefit Plan Disclosure [Line Items]
Unrecognized prior service credit	$ (1)

Pension and Postretirement P101

Pension and Postretirement Plans (Summary of Weighted-Average Assumptions) (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Pension Benefits | United States
Assumptions Used to Determine Benefit Obligations:
Discount rate	3.60%	3.95%
Rate of compensation increase	4.00%	4.00%
Assumptions Used to Determine Net Periodic Benefit Cost:
Discount rate	3.95%	4.35%
Expected return on plan assets	6.75%	6.75%
Rate of compensation increase	4.00%	4.00%
Pension Benefits | Int’l.
Assumptions Used to Determine Benefit Obligations:
Discount rate	2.36%	2.42%
Rate of compensation increase	3.74%	3.78%
Assumptions Used to Determine Net Periodic Benefit Cost:
Discount rate	2.46%	3.35%
Expected return on plan assets	4.74%	5.31%
Rate of compensation increase	3.78%	3.65%
Other Benefits
Assumptions Used to Determine Benefit Obligations:
Discount rate	3.35%	3.65%
Assumptions Used to Determine Net Periodic Benefit Cost:
Discount rate	3.65%	4.00%

Pension and Postretirement P102

Pension and Postretirement Plans (Summary of Pension Plan Asset Fair Values) (Details) - Pension Benefits - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
United States
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 2,751	$ 2,274	$ 2,023
Subtotal	1,440	601
United States | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,440	601
Subtotal	1,440	601
United States | Equity securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	589	533
United States | Equity securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	589	533
United States | Government debt securities
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	632
United States | Government debt securities | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	632
United States | Mutual funds
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	129	47
United States | Mutual funds | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	129	47
United States | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	90	21
United States | Cash and cash equivalents | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	90	21
United States | Common/collective trusts measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	1,311	1,673
Int’l.
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	972	796	$ 742
Subtotal	28	24
Int’l. | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6	5
Subtotal	6	5
Int’l. | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	22	19
Subtotal	22	19
Int’l. | Cash and cash equivalents
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6	5
Int’l. | Cash and cash equivalents | Level 1
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	6	5
Int’l. | Insurance contracts
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	14	13
Int’l. | Insurance contracts | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	14	13
Int’l. | Real estate
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	8	6
Int’l. | Real estate | Level 3
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	8	6
Int’l. | Common/collective trusts measured at NAV
Defined Benefit Plan Disclosure [Line Items]
Fair value of plan assets	$ 944	$ 772

Pension and Postretirement P103

Pension and Postretirement Plans (Summary of Future Service Benefit Payments) (Details) $ in Millions	Dec. 31, 2017USD ($)
Pension Benefits | United States
Defined Benefit Plan Disclosure [Line Items]
2,018	$ 329
2,019	302
2,020	294
2,021	290
2,022	292
2023-2026	1,298
Pension Benefits | Int’l.
Defined Benefit Plan Disclosure [Line Items]
2,018	22
2,019	22
2,020	24
2,021	26
2,022	27
2023-2026	162
Other Benefits
Defined Benefit Plan Disclosure [Line Items]
2,018	27
2,019	28
2,020	27
2,021	26
2,022	24
2023-2026	$ 101

Share-Based Compensation Pla104

Share-Based Compensation Plans (Narrative) (Details)	12 Months Ended
	Dec. 31, 2017USD ($)$ / sharesshares	Dec. 31, 2016USD ($)$ / shares	Dec. 31, 2015USD ($)$ / shares	Dec. 31, 2013shares	Dec. 31, 2009	Dec. 31, 2008	May 31, 2013shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Minimum service period to avoid award forfeiture	6 years
Weighted average grant date fair value of options granted (in dollars per share) | $ / shares	$ 16.95	$ 16.94	$ 18.84
Intrinsic value of options exercised	$ 62,000,000	$ 58,000,000	$ 60,000,000
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option terms in years	10 years
Weighted-average remaining contractual terms of vested options	5 years 5 months 23 days
Weighted-average remaining contractual terms of exercisable options	4 years 7 months 13 days
Cash received from the exercise of options	$ 35,000,000
Tax benefit from the exercise of options	9,000,000
Unrecognized compensation expense from unvested awards held by employees	$ 6,000,000
Weighted-average period for recognition of unrecognized compensation expense from unvested awards	20 months
Longest period for recognition of unrecognized compensation expense from unvested awards	27 months
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense from unvested awards held by employees	$ 50,000,000
Weighted-average period for recognition of unrecognized compensation expense from unvested awards	20 months
Longest period for recognition of unrecognized compensation expense from unvested awards	37 months
Units, granted (in dollars per share) | $ / shares	$ 78.49	$ 78.56	$ 74.09
Fair value of units issued	$ 85,000,000	$ 109,000,000	$ 107,000,000
Number of shares of common stock to be issued per stock unit | shares	1
Performance Shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense from unvested awards held by employees	$ 4,000,000
Weighted-average period for recognition of unrecognized compensation expense from unvested awards	23 months
Longest period for recognition of unrecognized compensation expense from unvested awards	9 years
Units, granted (in dollars per share) | $ / shares	$ 86.88	$ 78.62	$ 74.14
Fair value of units issued	$ 54,000,000	$ 26,000,000	$ 37,000,000
Performance measurement period						3 years
Eligible retirement age	55
Years of service	5 years				5 years
Number of shares of common stock to be issued per stock unit | shares				1
Fair value of cash settled units	$ 56,000,000	$ 60,000,000	$ 0
2013 Omnibus Stock And Performance Incentive Plan Of Phillips 66
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock issuable under P66 Omnibus Plan, maximum (in shares) | shares							45,000,000
Employees Eligible for Retirement | Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	6 months
Employees Eligible for Retirement | Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	6 months
Awards Vesting Ratably Over Three Years On Anniversary Of Grant Date | Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	3 years
Cliff Vesting | 2013 Omnibus Stock And Performance Incentive Plan Of Phillips 66 | Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Award vesting period	3 years

Share-Based Compensation Pla105

Share-Based Compensation Plans (Summary of Compensation Expense and Tax Benefit) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Share-based compensation expense	$ 142	$ 156	$ 144
Income tax benefit	$ (74)	$ (59)	$ (54)

Share-Based Compensation Pla106

Share-Based Compensation Plans (Summary of Stock Option Activity) (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Options
Options, outstanding, beginning of period (in shares)	5,103,130
Options, granted (in shares)	864,100
Options, forfeited (in shares)	(32,500)
Options, exercised (in shares)	(1,095,875)
Options, outstanding, end of period (in shares)	4,838,855	5,103,130
Options, vested, end of period (in shares)	4,191,679
Options, exercisable, end of period (in shares)	3,258,015
Weighted- Average Exercise Price
Weighted-Average exercise price, outstanding, beginning of period (in dollars per share)	$ 49.48
Weighted-Average exercise price, granted (in dollars per share)	78.48
Weighted-Average exercise price, forfeited (in dollars per share)	78.48
Weighted-Average exercise price, exercised (in dollars per share)	32.38
Weighted-Average exercise price, outstanding, end of period (in dollars per share)	58.34	$ 49.48
Weighted-Average exercise price, vested, End of period (in dollars per share)	55.25
Weighted-Average exercise price, exercisable, End of period (in dollars per share)	48.79
Weighted average grant date fair value of options granted (in dollars per share)	$ 16.95	$ 16.94	$ 18.84
Intrinsic value of options exercised	$ 62	$ 58	$ 60
Aggregate intrinsic value, options, vested, end of period	195
Aggregate intrinsic value, options, exercisable, end of period	$ 172

Share-Based Compensation Pla107

Share-Based Compensation Plans (Fair Value Assumptions) (Details) - Stock Options	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Risk-free interest rate	2.28%	1.71%	1.60%
Dividend yield	2.90%	3.00%	3.00%
Volatility factor	26.91%	28.68%	34.17%
Expected life (years)	7 years 2 months 19 days	7 years 29 days	6 years 7 months 28 days

Share-Based Compensation Pla108

Share-Based Compensation Plans (Summary of Stock Unit Activity) (Details) - Restricted Stock Units (RSUs) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Units
Units, Outstanding, beginning of period (in shares)	2,643,139
Units, Granted (in shares)	975,164
Units, Forfeited (in shares)	(58,171)
Units, Issued (in shares)	(1,063,707)
Units, Outstanding, end of period (in shares)	2,496,425	2,643,139
Units, Not Vested, end of period units, issued (in shares)	1,615,668
Weighted-Average Grant-Date Fair Value
Units, Outstanding, beginning of period (in dollars per share)	$ 71.28
Units, Granted (in dollars per share)	78.49	$ 78.56	$ 74.09
Units, Forfeited (in dollars per share)	77.18
Units, Issued (in dollars per share)	63.67
Units, Outstanding, end of period (in dollars per share)	77.20	$ 71.28
Units, Not Vested, end of period (in dollars per share)	$ 77.32
Units, Issued, Total Fair Value	$ 85	$ 109	$ 107

Share-Based Compensation Pla109

Share-Based Compensation Plans (Summary of Performance Share Activity) (Details) - Performance Shares - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Units
Units, Outstanding, beginning of period (in shares)	3,239,497
Units, Granted (in shares)	642,212
Units, Issued (in shares)	(681,219)
Units, Cash settled (in shares)	(642,212)
Units, Outstanding, end of period (in shares)	2,558,278	3,239,497
Units, Not Vested, end of period units, issued (in shares)	286,031
Weighted-Average Grant-Date Fair Value
Units, Outstanding, beginning of period (in dollars per share)	$ 50.12
Units, Granted (in dollars per share)	86.88	$ 78.62	$ 74.14
Units, Issued (in dollars per share)	42.85
Units, Cash settled (in dollars per share)	86.88
Units, Outstanding, end of period (in dollars per share)	52.06	$ 50.12
Units, Not Vested, end of period (in dollars per share)	$ 66.65
Units, Issued, Total Fair Value	$ 54,000,000	$ 26,000,000	$ 37,000,000
Units, Cash settled, Total Fair Value	$ 56,000,000	$ 60,000,000	$ 0

Income Taxes (Components of Inc

Income Taxes (Components of Income Tax Expense (Benefits)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Federal
Current	$ 9	$ (105)	$ 1,128
Deferred	(1,960)	645	444
Foreign
Current	126	66	(74)
Deferred	3	(84)	42
State and local
Current	61	(24)	227
Deferred	68	49	(3)
Income tax expense	$ (1,693)	$ 547	$ 1,764

Income Taxes (Deferred Income T

Income Taxes (Deferred Income Tax Liabilities and Assets) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Deferred Tax Liabilities
Properties, plants and equipment, and intangibles	$ 2,942	$ 4,525
Investment in joint ventures	1,923	2,442
Investment in subsidiaries	594	803
Inventory		154
Other	18	19
Total deferred tax liabilities	5,477	7,943
Deferred Tax Assets
Benefit plan accruals	314	669
Inventory	10
Asset retirement obligations and accrued environmental costs	121	211
Other financial accruals and deferrals	44	188
Loss and credit carryforwards	96	261
Other	3	1
Total deferred tax assets	588	1,330
Less: valuation allowance	28	38
Net deferred tax assets	560	1,292
Net deferred tax liabilities	$ 4,917	$ 6,651

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Mar. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Federal statutory income tax, percent		35.00%	35.00%	35.00%
Provisional deferred tax benefit		$ 2,870
Provisional income tax expense		149
Deferred tax assets, tax credit carryforwards, AMT		10
Decrease in valuation allowance		(10)
Unrecognized tax benefits that if recognized would affect our effective tax rate		5	$ 13	$ 34
Amount of unrecognized tax benefits and related liability which may be recognized or paid		2
Accrued liabilities for interest and penalties		8	12	19
Interest and penalties increased (decreased) earnings		1	7	3
Income tax expense (benefits) reflected in the Capital in Excess of Par column of the consolidated statement of equity		81	$ 150	(34)
Germany
Deferred tax assets, operating loss carryforwards, foreign		77
United Kingdom
Deferred tax assets, operating loss carryforwards, foreign		$ 7
Immingham Combined Heat and Power Plant
Tax benefit related to nontaxable gain included in Sale of foreign subsidiaries				$ 72
Scenario, Forecast
Federal statutory income tax, percent	21.00%

Income Taxes (Unrecognized Tax

Income Taxes (Unrecognized Tax Benefits) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Reconciliation of Unrecognized Tax Benefits [Roll Forward]
Balance at January 1	$ 70	$ 82	$ 142
Additions for tax positions of prior years	1	5	6
Reductions for tax positions of prior years	(5)	(17)	(17)
Settlements	(32)		(49)
Balance at December 31	$ 34	$ 70	$ 82

Income Taxes (Income Tax Reconc

Income Taxes (Income Tax Reconciliation) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income before income taxes
United States									$ 2,799	$ 1,713	$ 4,983
Foreign									756	478	1,061
Income before income taxes	$ 654	$ 1,256	$ 848	$ 797	$ 62	$ 813	$ 720	$ 596	$ 3,555	$ 2,191	$ 6,044
Percentage of Income Before Income Taxes
United States, percent									78.70%	78.20%	82.40%
Foreign, percent									21.30%	21.80%	17.60%
Total, percent of pre-tax income									100.00%	100.00%	100.00%
Income Tax Expense (Benefit), Income Tax Reconciliation
Federal statutory income tax									$ 1,244	$ 767	$ 2,115
State income tax, net of federal benefit									79	12	150
Tax Cuts and Jobs Act	$ (2,721)								(2,721)
Foreign rate differential									(210)	(152)	(239)
Noncontrolling interests									(46)	(26)	(13)
Federal manufacturing deduction									(18)		(77)
Change in valuation allowance									(4)	(81)	(17)
Goodwill allocated to assets sold											41
German tax legislation											(103)
Sale of foreign subsidiaries											(125)
Other									(17)	27	32
Income tax expense									$ (1,693)	$ 547	$ 1,764
Effective Income Tax Rate, Tax Rate Reconciliation
Federal statutory income tax, percent									35.00%	35.00%	35.00%
State income tax, net of federal benefit, percent									2.20%	0.60%	2.50%
Tax Cuts and Jobs Act, percent									(76.50%)
Foreign rate differential, percent									(5.90%)	(6.90%)	(3.90%)
Noncontrolling interests, percent									(1.30%)	(1.20%)	(0.20%)
Federal manufacturing deduction, percent									(0.50%)		(1.30%)
Change in valuation allowance, percent									(0.10%)	(3.70%)	(0.20%)
Goodwill allocated to assets sold, percent											0.70%
German tax legislation, percent											(1.70%)
Sale of foreign subsidiaries, percent											(2.10%)
Other, percent									(0.50%)	1.20%	0.40%
Effective income tax rate									(47.60%)	25.00%	29.20%

Accumulated Other Comprehens115

Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Accumulated other comprehensive income (loss)
Beginning Balance	$ 23,725	$ 23,938	$ 22,037
Net current period other comprehensive income (loss)	378	(342)	(122)
Accumulated other comprehensive income (loss), Ending Balance	(617)	(995)
Ending Balance	27,428	23,725	23,938
Defined Benefit Plans
Accumulated other comprehensive income (loss)
Beginning Balance	(713)	(662)	(696)
Other comprehensive loss before reclassification	3	(112)	(78)
Actuarial losses and settlements	112	61	112
Net current period other comprehensive income (loss)	115	(51)	34
Ending Balance	(598)	(713)	(662)
Foreign Currency Translation
Accumulated other comprehensive income (loss)
Beginning Balance	(285)	11	167
Other comprehensive loss before reclassification	259	(296)	(156)
Actuarial losses and settlements	0	0	0
Net current period other comprehensive income (loss)	259	(296)	(156)
Ending Balance	(26)	(285)	11
Hedging
Accumulated other comprehensive income (loss)
Beginning Balance	3	(2)	(2)
Other comprehensive loss before reclassification	4	5	0
Actuarial losses and settlements	0	0	0
Net current period other comprehensive income (loss)	4	5	0
Ending Balance	7	3	(2)
Accumulated Other Comprehensive Loss
Accumulated other comprehensive income (loss)
Beginning Balance	(995)	(653)	(531)
Other comprehensive loss before reclassification	266	(403)	(234)
Actuarial losses and settlements	112	61	112
Net current period other comprehensive income (loss)	378	(342)	(122)
Ending Balance	$ (617)	$ (995)	$ (653)

Cash Flow Information (Cash Pay

Cash Flow Information (Cash Payments (Receipts)) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash Payments (Receipts)
Interest	$ 421	$ 311	$ 275
Income taxes	(257)	(375)	$ 1,560
Income taxes paid	$ 102	$ 385

Cash Flow Information Cash Flow

Cash Flow Information Cash Flow Information (Narrative) (Details) - USD ($)	Dec. 31, 2017	Dec. 31, 2016
Supplemental Cash Flow Elements [Abstract]
Restricted Cash	$ 0	$ 0

Other Financial Information (De

Other Financial Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest and Debt Expense
Incurred, debt	$ 432	$ 402	$ 389
Incurred, other	21	17	27
Total incurred	453	419	416
Capitalized	(15)	(81)	(106)
Expensed	438	338	310
Other Income
Interest income	31	18	27
Gain on consolidation of business	423	0	0
Other, net	67	56	91
Other Income	521	74	118
Research and Development Expenditures—expensed	60	60	65
Advertising Expenses	76	80	73
Foreign Currency Transaction Gain (Loss), by Segment [Line Items]
Foreign Currency Transaction (Gains) Losses—after-tax		(11)	38
Refining
Foreign Currency Transaction Gain (Loss), by Segment [Line Items]
Foreign Currency Transaction (Gains) Losses—after-tax	(1)	(10)	34
Marketing and Specialties
Foreign Currency Transaction Gain (Loss), by Segment [Line Items]
Foreign Currency Transaction (Gains) Losses—after-tax	1	1	4
Corporate and Other
Interest and Debt Expense
Expensed	$ 438	338	$ 310
Foreign Currency Transaction Gain (Loss), by Segment [Line Items]
Foreign Currency Transaction (Gains) Losses—after-tax		$ (2)

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Significant transactions with related parties
Operating revenues and other income	$ 2,596	$ 2,174	$ 2,452
Purchases	10,468	8,109	8,142
Operating expenses and selling, general and administrative expenses	$ 79	$ 125	$ 129

Segment Disclosures and Rela120

Segment Disclosures and Related Information (Narrative) (Details)	12 Months Ended
	Dec. 31, 2017refinery
Refining | Mainly United States And Europe
Segment Disclosures and Related Information (Textual) [Abstract]
Number of refineries	13
DCP Midstream
Segment Disclosures and Related Information (Textual) [Abstract]
Equity investment	50.00%
DCP Midstream | Midstream
Segment Disclosures and Related Information (Textual) [Abstract]
Equity investment	50.00%
CP Chem
Segment Disclosures and Related Information (Textual) [Abstract]
Equity investment	50.00%
CP Chem | Chemicals
Segment Disclosures and Related Information (Textual) [Abstract]
Equity investment	50.00%

Segment Disclosures and Rela121

Segment Disclosures and Related Information (Summary of Sales and Other Operating Revenues and Depreciation, Amortization, and Impairments) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Analysis of results of sales and other operating revenues by operating segment
Sales and other operating revenues	$ 29,746	$ 25,627	$ 24,087	$ 22,894	$ 23,397	$ 21,624	$ 21,849	$ 17,409	$ 102,354	[1]	$ 84,279	[1]	$ 98,975	[1]
Analysis of results of depreciation, amortization and impairments by operating segment
Depreciation, Amortization and Impairments									1,342		1,173		1,085
Midstream
Analysis of results of sales and other operating revenues by operating segment
Sales and other operating revenues									4,778		2,927		2,642
Analysis of results of depreciation, amortization and impairments by operating segment
Depreciation, Amortization and Impairments									299		218		128
Chemicals
Analysis of results of sales and other operating revenues by operating segment
Sales and other operating revenues									5		5		5
Refining
Analysis of results of sales and other operating revenues by operating segment
Sales and other operating revenues									25,210		17,948		23,153
Analysis of results of depreciation, amortization and impairments by operating segment
Depreciation, Amortization and Impairments									838		770		741
Marketing and Specialties
Analysis of results of sales and other operating revenues by operating segment
Sales and other operating revenues									72,332		63,367		73,145
Analysis of results of depreciation, amortization and impairments by operating segment
Depreciation, Amortization and Impairments									116		107		100
Operating Segments | Midstream
Analysis of results of sales and other operating revenues by operating segment
Sales and other operating revenues									6,620		4,226		3,676
Operating Segments | Refining
Analysis of results of sales and other operating revenues by operating segment
Sales and other operating revenues									65,494		52,068		63,470
Operating Segments | Marketing and Specialties
Analysis of results of sales and other operating revenues by operating segment
Sales and other operating revenues									73,565		64,476		74,591
Intersegment Eliminations | Midstream
Analysis of results of sales and other operating revenues by operating segment
Sales and other operating revenues									(1,842)		(1,299)		(1,034)
Intersegment Eliminations | Refining
Analysis of results of sales and other operating revenues by operating segment
Sales and other operating revenues									(40,284)		(34,120)		(40,317)
Intersegment Eliminations | Marketing and Specialties
Analysis of results of sales and other operating revenues by operating segment
Sales and other operating revenues									(1,233)		(1,109)		(1,446)
Corporate and Other
Analysis of results of sales and other operating revenues by operating segment
Sales and other operating revenues									29		32		30
Analysis of results of depreciation, amortization and impairments by operating segment
Depreciation, Amortization and Impairments									$ 89		$ 78		$ 116
[1]	Includes excise taxes on petroleum products sales: $13,054 million, $13,381 million, $13,780 million

Segment Disclosures and Rela122

Segment Disclosures and Related Information (Summary of Equity in Earnings of Affiliates, Income Taxes, and Net Income) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Analysis of results of equity in earnings of affiliates by operating segment
Equity in earnings (losses) of affiliates									$ 1,732	$ 1,414	$ 1,573
Income tax expense (benefit)									(1,693)	547	1,764
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest	$ 3,255	$ 849	$ 581	$ 563	$ 194	$ 536	$ 516	$ 398	5,248	1,644	4,280
Net Income Attributable to Phillips 66	$ 3,198	$ 823	$ 550	$ 535	$ 163	$ 511	$ 496	$ 385	5,106	1,555	4,227
Midstream
Analysis of results of equity in earnings of affiliates by operating segment
Equity in earnings (losses) of affiliates									454	184	(268)
Income tax expense (benefit)									174	123	73
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest									464	280	74
Chemicals
Analysis of results of equity in earnings of affiliates by operating segment
Equity in earnings (losses) of affiliates									713	834	1,316
Income tax expense (benefit)									191	256	353
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest									525	583	962
Refining
Analysis of results of equity in earnings of affiliates by operating segment
Equity in earnings (losses) of affiliates									322	164	325
Income tax expense (benefit)									672	61	1,104
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest									1,404	374	2,555
Marketing and Specialties
Analysis of results of equity in earnings of affiliates by operating segment
Equity in earnings (losses) of affiliates									243	232	207
Income tax expense (benefit)									334	370	466
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest									686	891	1,187
Corporate and Other
Analysis of results of equity in earnings of affiliates by operating segment
Equity in earnings (losses) of affiliates											(7)
Income tax expense (benefit)									(3,064)	(263)	(232)
Net Income (Loss), Including Portion Attributable to Noncontrolling Interest									$ 2,169	$ (484)	$ (498)

Segment Disclosures and Rela123

Segment Disclosures and Related Information (Summary of Investments In and Advances to Affiliates, Total Assets, Capital Expenditures and Investments, Interest Income and Expense) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Analysis of results of investments in and advances to affiliates by operating segment
Investments In and Advances To Affiliates	$ 13,744	$ 13,354	$ 11,980
Analysis of results of total assets by operating segment
Total Assets	54,371	51,653	48,580
Capital Expenditures and Investments
Capital Expenditures and Investments	1,832	2,844	5,764
Interest Income and Expense
Interest income	31	18	27
Interest and debt expense	438	338	310
Midstream
Analysis of results of investments in and advances to affiliates by operating segment
Investments In and Advances To Affiliates	4,734	4,769	4,198
Analysis of results of total assets by operating segment
Total Assets	13,231	12,832	11,043
Capital Expenditures and Investments
Capital Expenditures and Investments	771	1,453	4,457
Interest Income and Expense
Interest income	1	2
Chemicals
Analysis of results of investments in and advances to affiliates by operating segment
Investments In and Advances To Affiliates	6,222	5,773	5,177
Analysis of results of total assets by operating segment
Total Assets	6,226	5,802	5,237
Refining
Analysis of results of investments in and advances to affiliates by operating segment
Investments In and Advances To Affiliates	2,398	2,420	2,262
Analysis of results of total assets by operating segment
Total Assets	23,820	22,825	21,993
Capital Expenditures and Investments
Capital Expenditures and Investments	853	1,149	1,069
Marketing and Specialties
Analysis of results of investments in and advances to affiliates by operating segment
Investments In and Advances To Affiliates	390	391	342
Analysis of results of total assets by operating segment
Total Assets	7,103	6,227	5,631
Capital Expenditures and Investments
Capital Expenditures and Investments	108	98	122
Interest Income and Expense
Interest income			2
Corporate and Other
Analysis of results of investments in and advances to affiliates by operating segment
Investments In and Advances To Affiliates		1	1
Analysis of results of total assets by operating segment
Total Assets	3,991	3,967	4,676
Capital Expenditures and Investments
Capital Expenditures and Investments	100	144	116
Interest Income and Expense
Interest income	30	16	25
Interest and debt expense	$ 438	$ 338	$ 310

Segment Disclosures and Rela124

Segment Disclosures and Related Information (Summary of Sales and Other Operating Revenues by Product Line) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Analysis of results of sales and other operating revenues by product line by operating segment [Abstract]
Sales and other operating revenues	$ 29,746	$ 25,627	$ 24,087	$ 22,894	$ 23,397	$ 21,624	$ 21,849	$ 17,409	$ 102,354	[1]	$ 84,279	[1]	$ 98,975	[1]
Refined products
Analysis of results of sales and other operating revenues by product line by operating segment [Abstract]
Sales and other operating revenues									85,405		73,385		86,249
Crude oil resales
Analysis of results of sales and other operating revenues by product line by operating segment [Abstract]
Sales and other operating revenues									11,808		7,594		8,993
NGL
Analysis of results of sales and other operating revenues by product line by operating segment [Abstract]
Sales and other operating revenues									4,670		3,107		2,998
Other
Analysis of results of sales and other operating revenues by product line by operating segment [Abstract]
Sales and other operating revenues									$ 471		$ 193		$ 735
[1]	Includes excise taxes on petroleum products sales: $13,054 million, $13,381 million, $13,780 million

Segment Disclosures and Rela125

Segment Disclosures and Related Information (Summary of Geographic Information) (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Analysis of results of sales and other operating revenues and long-lived assets by geographical location [Abstract]
Sales and other operating revenues	$ 29,746	$ 25,627	$ 24,087	$ 22,894	$ 23,397	$ 21,624	$ 21,849	$ 17,409	$ 102,354	[1]	$ 84,279	[1]	$ 98,975	[1]
Long-Lived Assets	35,204				34,209				35,204		34,209		31,701
United States
Analysis of results of sales and other operating revenues and long-lived assets by geographical location [Abstract]
Sales and other operating revenues									75,684		59,742		69,578
Long-Lived Assets	33,264				32,442				33,264		32,442		29,624
United Kingdom
Analysis of results of sales and other operating revenues and long-lived assets by geographical location [Abstract]
Sales and other operating revenues									10,626		9,895		12,120
Long-Lived Assets	1,254				1,177				1,254		1,177		1,459
Germany
Analysis of results of sales and other operating revenues and long-lived assets by geographical location [Abstract]
Sales and other operating revenues									6,692		6,128		6,584
Long-Lived Assets	591				503				591		503		502
Other foreign countries
Analysis of results of sales and other operating revenues and long-lived assets by geographical location [Abstract]
Sales and other operating revenues									9,352		8,514		10,693
Long-Lived Assets	$ 95				$ 87				$ 95		$ 87		$ 116
[1]	Includes excise taxes on petroleum products sales: $13,054 million, $13,381 million, $13,780 million

Phillips 66 Partners LP (Detail

Phillips 66 Partners LP (Details) - USD ($)	Jan. 23, 2018	Dec. 31, 2017	Oct. 31, 2017	Jun. 30, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2017
Subsidiary or Equity Method Investee [Line Items]
Public's ownership interest in Phillips 66 Partners reflected as a noncontrolling interest		$ 2,343,000,000			$ 2,343,000,000	$ 1,335,000,000		$ 2,343,000,000
Preferred units, distribution, after three years (in usd per share)			$ 0.678375
Proceeds from Issuance of Common Limited Partners Units					$ 1,205,000,000	972,000,000	$ 384,000,000
Phillips 66 Partners LP
Subsidiary or Equity Method Investee [Line Items]
Limited partner interest in Phillips 66 Partners owned by public, percentage		43.00%
Preferred Units | Phillips 66 Partners LP
Subsidiary or Equity Method Investee [Line Items]
Limited partner interest in Phillips 66 Partners owned by public (in shares)		13,800,000			13,800,000			13,800,000
Common Units | Phillips 66 Partners LP
Subsidiary or Equity Method Investee [Line Items]
Partners' capital account, units, amount authorized				$ 250,000,000
Phillips 66 Partners | Phillips 66 Partners LP
Subsidiary or Equity Method Investee [Line Items]
Limited partnership interest in Phillips 66 Partners, percentage		55.00%
General partnership interest in Phillips 66 Partners, percentage		2.00%
Phillips 66 Partners | Phillips 66 Partners LP | Noncontrolling Interests
Subsidiary or Equity Method Investee [Line Items]
Public's ownership interest in Phillips 66 Partners reflected as a noncontrolling interest		$ 2,314,000,000			$ 2,314,000,000	$ 1,306,000,000		$ 2,314,000,000
Phillips 66 Partners | Phillips 66 Partners LP | Loans Payable
Subsidiary or Equity Method Investee [Line Items]
Senior notes			$ 450,000,000
Phillips 66 Partners | Phillips 66 Partners LP | Senior Notes
Subsidiary or Equity Method Investee [Line Items]
Senior notes			650,000,000
Common Control Transaction | Phillips 66 Partners | Phillips 66 Partners LP | Phillips 66
Subsidiary or Equity Method Investee [Line Items]
Consideration transferred			1,650,000,000
Payments to acquire businesses			372,000,000
Acquired and liabilities assumed, long-term debt			588,000,000
Cash consideration			960,000,000
Common Control Transaction | Phillips 66 Partners | Phillips 66 Partners LP | Common And General Partner Units | Phillips 66
Subsidiary or Equity Method Investee [Line Items]
Entities under common control, fair value units received on transfer of interest in subsidiary			240,000,000
Common Control Transaction | Phillips 66 Partners | Phillips 66 Partners LP | Loans Payable | Phillips 66
Subsidiary or Equity Method Investee [Line Items]
Acquired and liabilities assumed, long-term debt			450,000,000
Common Control Transaction | Phillips 66 Partners | Phillips 66 Partners LP | Senior Notes
Subsidiary or Equity Method Investee [Line Items]
Proceeds from Debt, Net of Issuance Costs			643,000,000
Senior notes			650,000,000
Common Control Transaction | Phillips 66 Partners | Preferred Units | Phillips 66 Partners LP
Subsidiary or Equity Method Investee [Line Items]
Proceeds from issuance of preferred limited partners units			$ 737,000,000
Sold in private placement (in shares)			13,819,791
Sale of stock (in dollars per share)			$ 54.27
Preferred units, Distribution, Quarterly (in usd per share)			$ 0.678375
Common Control Transaction | Phillips 66 Partners | Common Units | Phillips 66 Partners LP
Subsidiary or Equity Method Investee [Line Items]
Sold in private placement (in shares)			6,304,204
Sale of stock (in dollars per share)			$ 47.59
Proceeds from Issuance of Common Limited Partners Units			$ 295,000,000
Common Control Transaction | DAPL | Phillips 66 Partners LP | Phillips 66
Subsidiary or Equity Method Investee [Line Items]
Percentage of ownership interest			25.00%
Common Control Transaction | Merey Sweeny L.P. | Phillips 66 Partners LP
Subsidiary or Equity Method Investee [Line Items]
Percentage of ownership In subsidiary			100.00%
Common Control Transaction | Merey Sweeny L.P. | Phillips 66 Partners LP | Phillips 66
Subsidiary or Equity Method Investee [Line Items]
Percentage of ownership In subsidiary			100.00%
At The Market Offering Program | Common Units | Phillips 66 Partners LP
Subsidiary or Equity Method Investee [Line Items]
Phillips 66 Partners IPO, common units issued (in shares)					3,372,716			3,718,868
Net proceeds					$ 173,000,000			$ 192,000,000
Subsequent Event | Common Units | Phillips 66 Partners LP
Subsidiary or Equity Method Investee [Line Items]
Partners' capital account, units, amount authorized	$ 250,000,000

Condensed Consolidating Fina127

Condensed Consolidating Financial Information (Narrative) (Details) $ in Billions	Dec. 31, 2017USD ($)
Phillips 66 Company
Condensed Financial Statements, Captions [Line Items]
Percentage of ownership In subsidiary	100.00%
Senior Notes | Phillips 66
Condensed Financial Statements, Captions [Line Items]
Senior notes	$ 6

Condensed Consolidating Fina128

Condensed Consolidating Financial Information (Income Statement) (Details) - USD ($) $ in Millions		3 Months Ended								12 Months Ended
		Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Revenues and Other Income
Sales and other operating revenues		$ 29,746	$ 25,627	$ 24,087	$ 22,894	$ 23,397	$ 21,624	$ 21,849	$ 17,409	$ 102,354	[1]	$ 84,279	[1]	$ 98,975	[1]
Equity in earnings (losses) of affiliates										1,732		1,414		1,573
Net gain (loss) on dispositions										15		10		283
Other income (loss)										521		74		118
Total Revenues and Other Income										104,622		85,777		100,949
Costs and Expenses
Purchased crude oil and products										79,409		62,468		73,399
Operating expenses										4,699		4,275		4,294
Selling, general and administrative expenses										1,695		1,638		1,670
Depreciation and amortization										1,318		1,168		1,078
Impairments										24		5		7
Taxes other than income taxes	[1]									13,462		13,688		14,077
Accretion on discounted liabilities										22		21		21
Interest and debt expense										438		338		310
Foreign currency transaction (gains) losses										0		(15)		49
Total Costs and Expenses										101,067		83,586		94,905
Income before income taxes										3,555		2,191		6,044
Income tax expense (benefit)										(1,693)		547		1,764
Net Income		3,255	849	581	563	194	536	516	398	5,248		1,644		4,280
Less: net income attributable to noncontrolling interests										142		89		53
Net Income Attributable to Phillips 66		$ 3,198	$ 823	$ 550	$ 535	$ 163	$ 511	$ 496	$ 385	5,106		1,555		4,227
Comprehensive Income										5,626		1,302		4,158
Reportable Legal Entities | Phillips 66
Revenues and Other Income
Sales and other operating revenues												0		0
Equity in earnings (losses) of affiliates										5,336		1,797		4,470
Net gain (loss) on dispositions												0		0
Other income (loss)										3		0		0
Total Revenues and Other Income										5,339		1,797		4,470
Costs and Expenses
Purchased crude oil and products												0
Operating expenses												0		4
Selling, general and administrative expenses										7		6		5
Depreciation and amortization												0		0
Impairments												0		0
Taxes other than income taxes												0		0
Accretion on discounted liabilities												0		0
Interest and debt expense										348		366		365
Foreign currency transaction (gains) losses												0		0
Total Costs and Expenses										355		372		374
Income before income taxes										4,984		1,425		4,096
Income tax expense (benefit)										(122)		(130)		(131)
Net Income										5,106		1,555		4,227
Less: net income attributable to noncontrolling interests												0		0
Net Income Attributable to Phillips 66										5,106		1,555		4,227
Comprehensive Income										5,484		1,213		4,105
Reportable Legal Entities | Phillips 66 Company
Revenues and Other Income
Sales and other operating revenues										74,640		58,822		68,478
Equity in earnings (losses) of affiliates										3,256		1,839		2,812
Net gain (loss) on dispositions										1		(9)		(115)
Other income (loss)										471		42		81
Total Revenues and Other Income										79,978		61,558		72,327
Costs and Expenses
Purchased crude oil and products										63,812		48,171		54,925
Operating expenses										3,672		3,465		3,412
Selling, general and administrative expenses										1,300		1,236		1,265
Depreciation and amortization										892		821		818
Impairments										20		1		4
Taxes other than income taxes										5,784		5,477		5,505
Accretion on discounted liabilities										17		16		16
Interest and debt expense										70		21		25
Foreign currency transaction (gains) losses												0		1
Total Costs and Expenses										75,567		59,208		65,971
Income before income taxes										4,411		2,350		6,356
Income tax expense (benefit)										(925)		553		1,886
Net Income										5,336		1,797		4,470
Less: net income attributable to noncontrolling interests												0		0
Net Income Attributable to Phillips 66										5,336		1,797		4,470
Comprehensive Income										5,714		1,455		4,348
Reportable Legal Entities | All Other Subsidiaries
Revenues and Other Income
Sales and other operating revenues										27,714		25,457		30,497
Equity in earnings (losses) of affiliates										559		296		(134)
Net gain (loss) on dispositions										14		19		398
Other income (loss)										47		32		37
Total Revenues and Other Income										41,791		34,964		40,643
Costs and Expenses
Purchased crude oil and products										30,379		24,102		29,221
Operating expenses										1,085		846		917
Selling, general and administrative expenses										399		406		416
Depreciation and amortization										426		347		260
Impairments										4		4		3
Taxes other than income taxes										7,678		8,211		8,572
Accretion on discounted liabilities										5		5		5
Interest and debt expense										236		124		34
Foreign currency transaction (gains) losses												(15)		48
Total Costs and Expenses										40,212		34,030		39,476
Income before income taxes										1,579		934		1,167
Income tax expense (benefit)										(646)		124		9
Net Income										2,225		810		1,158
Less: net income attributable to noncontrolling interests										142		89		53
Net Income Attributable to Phillips 66										2,083		721		1,105
Comprehensive Income										2,498		451		1,032
Consolidating Adjustments
Revenues and Other Income
Sales and other operating revenues										(15,067)		(10,024)		(10,916)
Equity in earnings (losses) of affiliates										(7,419)		(2,518)		(5,575)
Net gain (loss) on dispositions												0		0
Other income (loss)												0		0
Total Revenues and Other Income										(22,486)		(12,542)		(16,491)
Costs and Expenses
Purchased crude oil and products										(14,782)		(9,805)		(10,747)
Operating expenses										(58)		(36)		(39)
Selling, general and administrative expenses										(11)		(10)		(16)
Depreciation and amortization												0		0
Impairments												0		0
Taxes other than income taxes												0		0
Accretion on discounted liabilities												0		0
Interest and debt expense										(216)		(173)		(114)
Foreign currency transaction (gains) losses												0		0
Total Costs and Expenses										(15,067)		(10,024)		(10,916)
Income before income taxes										(7,419)		(2,518)		(5,575)
Income tax expense (benefit)												0		0
Net Income										(7,419)		(2,518)		(5,575)
Less: net income attributable to noncontrolling interests												0		0
Net Income Attributable to Phillips 66										(7,419)		(2,518)		(5,575)
Comprehensive Income										(8,070)		(1,817)		(5,327)
Consolidating Adjustments | Phillips 66
Revenues and Other Income
Sales and other operating revenues												0		0
Consolidating Adjustments | Phillips 66 Company
Revenues and Other Income
Sales and other operating revenues										1,610		864		1,071
Consolidating Adjustments | All Other Subsidiaries
Revenues and Other Income
Sales and other operating revenues										$ 13,457		$ 9,160		$ 9,845
[1]	Includes excise taxes on petroleum products sales: $13,054 million, $13,381 million, $13,780 million

Condensed Consolidating Fina129

Condensed Consolidating Financial Information (Balance Sheet) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Assets
Cash and cash equivalents	$ 3,119	$ 2,711
Accounts and notes receivable	7,506	6,397
Inventories	3,395	3,150
Prepaid expenses and other current assets	370	422
Total Current Assets	14,390	12,680
Investments and long-term receivables	13,941	13,534
Net properties, plants and equipment	21,460	20,855
Goodwill	3,270	3,270	$ 3,275
Intangibles	876	888
Other assets	434	426
Total Assets	54,371	51,653	$ 48,580
Liabilities and Equity
Accounts payable	8,027	7,061
Short-term debt	41	550
Accrued income and other taxes	1,002	805
Employee benefit obligations	582	527
Other accruals	455	520
Total Current Liabilities	10,107	9,463
Long-term debt	10,069	9,588
Asset retirement obligations and accrued environmental costs	641	655
Deferred income taxes	5,008	6,743
Employee benefit obligations	884	1,216
Other liabilities and deferred credits	234	263
Total Liabilities	26,943	27,928
Common stock	9,396	10,777
Retained earnings	16,306	12,608
Accumulated other comprehensive income (loss)	(617)	(995)
Noncontrolling interests	2,343	1,335
Total Liabilities and Equity	54,371	51,653
Consolidating Adjustments
Assets
Cash and cash equivalents	0	0
Accounts and notes receivable	(2,297)	(1,228)
Inventories	0	0
Prepaid expenses and other current assets	0	0
Total Current Assets	(2,297)	(1,228)
Investments and long-term receivables	(51,626)	(48,952)
Net properties, plants and equipment	0	0
Goodwill	0	0
Intangibles	0	0
Other assets	(2)	(2)
Total Assets	(53,925)	(50,182)
Liabilities and Equity
Accounts payable	(2,297)	(1,228)
Short-term debt	0	0
Accrued income and other taxes	0	0
Employee benefit obligations	0	0
Other accruals	0	0
Total Current Liabilities	(2,297)	(1,228)
Long-term debt	0	0
Asset retirement obligations and accrued environmental costs	0	0
Deferred income taxes	(2)	(2)
Employee benefit obligations	0	0
Other liabilities and deferred credits	(8,288)	(8,431)
Total Liabilities	(10,587)	(9,661)
Common stock	(35,077)	(35,520)
Retained earnings	(9,083)	(6,474)
Accumulated other comprehensive income (loss)	822	1,473
Noncontrolling interests	0	0
Total Liabilities and Equity	(53,925)	(50,182)
Phillips 66 | Reportable Legal Entities
Assets
Cash and cash equivalents	0	0
Accounts and notes receivable	10	13
Inventories	0	0
Prepaid expenses and other current assets	2	2
Total Current Assets	12	15
Investments and long-term receivables	32,125	31,165
Net properties, plants and equipment	0	0
Goodwill	0	0
Intangibles	0	0
Other assets	12	15
Total Assets	32,149	31,195
Liabilities and Equity
Accounts payable	0	0
Short-term debt	0	500
Accrued income and other taxes	0	0
Employee benefit obligations	0	0
Other accruals	55	59
Total Current Liabilities	55	559
Long-term debt	6,972	6,920
Asset retirement obligations and accrued environmental costs	0	0
Deferred income taxes	0	0
Employee benefit obligations	0	0
Other liabilities and deferred credits	8	1,297
Total Liabilities	7,035	8,776
Common stock	9,396	10,777
Retained earnings	16,335	12,637
Accumulated other comprehensive income (loss)	(617)	(995)
Noncontrolling interests	0	0
Total Liabilities and Equity	32,149	31,195
Phillips 66 Company | Reportable Legal Entities
Assets
Cash and cash equivalents	1,411	854
Accounts and notes receivable	5,317	4,336
Inventories	2,386	2,198
Prepaid expenses and other current assets	276	317
Total Current Assets	9,390	7,705
Investments and long-term receivables	23,483	22,733
Net properties, plants and equipment	13,117	13,044
Goodwill	2,853	2,853
Intangibles	722	719
Other assets	266	245
Total Assets	49,831	47,299
Liabilities and Equity
Accounts payable	7,272	5,626
Short-term debt	9	30
Accrued income and other taxes	451	348
Employee benefit obligations	513	475
Other accruals	298	371
Total Current Liabilities	8,543	6,850
Long-term debt	50	150
Asset retirement obligations and accrued environmental costs	467	501
Deferred income taxes	3,349	4,391
Employee benefit obligations	639	948
Other liabilities and deferred credits	4,700	3,337
Total Liabilities	17,748	16,177
Common stock	24,952	25,403
Retained earnings	7,748	6,714
Accumulated other comprehensive income (loss)	(617)	(995)
Noncontrolling interests	0	0
Total Liabilities and Equity	49,831	47,299
All Other Subsidiaries | Reportable Legal Entities
Assets
Cash and cash equivalents	1,708	1,857
Accounts and notes receivable	4,476	3,276
Inventories	1,009	952
Prepaid expenses and other current assets	92	103
Total Current Assets	7,285	6,188
Investments and long-term receivables	9,959	8,588
Net properties, plants and equipment	8,343	7,811
Goodwill	417	417
Intangibles	154	169
Other assets	158	168
Total Assets	26,316	23,341
Liabilities and Equity
Accounts payable	3,052	2,663
Short-term debt	32	20
Accrued income and other taxes	551	457
Employee benefit obligations	69	52
Other accruals	102	90
Total Current Liabilities	3,806	3,282
Long-term debt	3,047	2,518
Asset retirement obligations and accrued environmental costs	174	154
Deferred income taxes	1,661	2,354
Employee benefit obligations	245	268
Other liabilities and deferred credits	3,814	4,060
Total Liabilities	12,747	12,636
Common stock	10,125	10,117
Retained earnings	1,306	(269)
Accumulated other comprehensive income (loss)	(205)	(478)
Noncontrolling interests	2,343	1,335
Total Liabilities and Equity	$ 26,316	$ 23,341

Condensed Consolidating Fina130

Condensed Consolidating Financial Information (Cash Flow) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash Flows From Operating Activities
Net Cash Provided by Operating Activities		$ 3,648	$ 2,963	$ 5,713
Cash Flows From Investing Activities
Capital expenditures and investments		(1,832)	(2,844)	(5,764)
Proceeds from asset dispositions	[1]	86	156	70
Intercompany lending activities		0	0	0
Advances/loans—related parties		(10)	(432)	(50)
Collection of advances/loans—related parties		326	108	50
Restricted cash received from consolidation of business		318	0	0
Other		(34)	(146)	(44)
Net Cash Used in Investing Activities		(1,146)	(3,158)	(5,738)
Cash Flows From Financing Activities
Issuance of debt		3,508	2,090	1,169
Repayment of debt		(3,678)	(833)	(926)
Issuance of common stock		35	34	31
Repurchase of common stock		(1,590)	(1,042)	(1,512)
Dividends paid on common stock		(1,395)	(1,282)	(1,172)
Distributions to noncontrolling interests				0
Distributions to noncontrolling interests		(120)	(75)	(46)
Net proceeds from issuance of Phillips 66 Partners LP common and preferred units		1,205	972	384
Other		(76)	(42)	(45)
Net Cash Used in Financing Activities		(2,111)	(178)	(2,117)
Effect of Exchange Rate Changes on Cash, Cash Equivalents and Restricted Cash		17	10	9
Net Change in Cash, Cash Equivalents and Restricted Cash		408	(363)	(2,133)
Cash, cash equivalents and restricted cash at beginning of period		2,711	3,074	5,207
Cash, Cash Equivalents and Restricted Cash at End of Period		3,119	2,711	3,074
Consolidating Adjustments
Cash Flows From Operating Activities
Net Cash Provided by Operating Activities		(3,420)	(4,387)	(2,790)
Cash Flows From Investing Activities
Capital expenditures and investments		140	38	2,334
Proceeds from asset dispositions		(263)	(1,007)	(882)
Intercompany lending activities		0	0	0
Advances/loans—related parties		0	0	0
Collection of advances/loans—related parties		0	0	0
Restricted cash received from consolidation of business		0
Other		0	0	0
Net Cash Used in Investing Activities		(123)	(969)	1,452
Cash Flows From Financing Activities
Issuance of debt		0	0	0
Repayment of debt		0	0	0
Issuance of common stock		0	0	0
Repurchase of common stock		0	0	0
Dividends paid on common stock		3,420	4,387	2,748
Distributions to noncontrolling interests				186
Distributions to noncontrolling interests		0	0	0
Net proceeds from issuance of Phillips 66 Partners LP common and preferred units		0	0	0
Other		123	969	(1,596)
Net Cash Used in Financing Activities		3,543	5,356	1,338
Effect of Exchange Rate Changes on Cash, Cash Equivalents and Restricted Cash		0	0	0
Net Change in Cash, Cash Equivalents and Restricted Cash		0	0	0
Cash, cash equivalents and restricted cash at beginning of period		0	0	0
Cash, Cash Equivalents and Restricted Cash at End of Period		0	0	0
Phillips 66 | Reportable Legal Entities
Cash Flows From Operating Activities
Net Cash Provided by Operating Activities		2,619	3,491	1,060
Cash Flows From Investing Activities
Capital expenditures and investments		0	0	0
Proceeds from asset dispositions		0	0	0
Intercompany lending activities		401	(1,139)	2,461
Advances/loans—related parties		0	0	0
Collection of advances/loans—related parties		0	0	0
Restricted cash received from consolidation of business		0
Other		0	0	0
Net Cash Used in Investing Activities		401	(1,139)	2,461
Cash Flows From Financing Activities
Issuance of debt		1,500	0	0
Repayment of debt		(1,500)	0	(800)
Issuance of common stock		35	34	31
Repurchase of common stock		(1,590)	(1,042)	(1,512)
Dividends paid on common stock		(1,395)	(1,282)	(1,172)
Distributions to noncontrolling interests				0
Distributions to noncontrolling interests		0	0	0
Net proceeds from issuance of Phillips 66 Partners LP common and preferred units		0	0	0
Other		(70)	(62)	(68)
Net Cash Used in Financing Activities		(3,020)	(2,352)	(3,521)
Effect of Exchange Rate Changes on Cash, Cash Equivalents and Restricted Cash		0	0	0
Net Change in Cash, Cash Equivalents and Restricted Cash		0	0	0
Cash, cash equivalents and restricted cash at beginning of period		0	0	0
Cash, Cash Equivalents and Restricted Cash at End of Period		0	0	0
Phillips 66 Company | Reportable Legal Entities
Cash Flows From Operating Activities
Net Cash Provided by Operating Activities		2,702	2,307	4,879
Cash Flows From Investing Activities
Capital expenditures and investments		(1,133)	(1,425)	(2,815)
Proceeds from asset dispositions		265	1,007	774
Intercompany lending activities		1,453	2,046	(3,153)
Advances/loans—related parties		(10)	(75)	(50)
Collection of advances/loans—related parties		75	0	50
Restricted cash received from consolidation of business		0
Other		(26)	18	6
Net Cash Used in Investing Activities		624	1,571	(5,188)
Cash Flows From Financing Activities
Issuance of debt		0	0	0
Repayment of debt		(17)	(26)	(23)
Issuance of common stock		0	0	0
Repurchase of common stock		0	0	0
Dividends paid on common stock		(2,752)	(3,604)	(1,172)
Distributions to noncontrolling interests				0
Distributions to noncontrolling interests		0	0	0
Net proceeds from issuance of Phillips 66 Partners LP common and preferred units		0	0	0
Other		0	31	34
Net Cash Used in Financing Activities		(2,769)	(3,599)	(1,161)
Effect of Exchange Rate Changes on Cash, Cash Equivalents and Restricted Cash		0	0	0
Net Change in Cash, Cash Equivalents and Restricted Cash		557	279	(1,470)
Cash, cash equivalents and restricted cash at beginning of period		854	575	2,045
Cash, Cash Equivalents and Restricted Cash at End of Period		1,411	854	575
All Other Subsidiaries | Reportable Legal Entities
Cash Flows From Operating Activities
Net Cash Provided by Operating Activities		1,747	1,552	2,564
Cash Flows From Investing Activities
Capital expenditures and investments		(839)	(1,457)	(5,283)
Proceeds from asset dispositions		84	156	178
Intercompany lending activities		(1,854)	(907)	692
Advances/loans—related parties		0	(357)	0
Collection of advances/loans—related parties		251	108	0
Restricted cash received from consolidation of business		318
Other		(8)	(164)	(50)
Net Cash Used in Investing Activities		(2,048)	(2,621)	(4,463)
Cash Flows From Financing Activities
Issuance of debt		2,008	2,090	1,169
Repayment of debt		(2,161)	(807)	(103)
Issuance of common stock		0	0	0
Repurchase of common stock		0	0	0
Dividends paid on common stock		(668)	(783)	(1,576)
Distributions to noncontrolling interests				(186)
Distributions to noncontrolling interests		(120)	(75)	(46)
Net proceeds from issuance of Phillips 66 Partners LP common and preferred units		1,205	972	384
Other		(129)	(980)	1,585
Net Cash Used in Financing Activities		135	417	1,227
Effect of Exchange Rate Changes on Cash, Cash Equivalents and Restricted Cash		17	10	9
Net Change in Cash, Cash Equivalents and Restricted Cash		(149)	(642)	(663)
Cash, cash equivalents and restricted cash at beginning of period		1,857	2,499	3,162
Cash, Cash Equivalents and Restricted Cash at End of Period		$ 1,708	1,857	$ 2,499
Restatement Adjustment [Member] | All Other Subsidiaries | Consolidating Adjustments
Cash Flows From Operating Activities
Net Cash Provided by Operating Activities			1,049
Cash Flows From Financing Activities
Net Cash Used in Financing Activities			$ (1,049)
[1]	Includes return of investments in equity affiliates.

Selected Quarterly Financial131

Selected Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Selected Quarterly Financial Information [Abstract]
Sales and other operating revenues	$ 29,746	$ 25,627	$ 24,087	$ 22,894	$ 23,397	$ 21,624	$ 21,849	$ 17,409	$ 102,354	[1]	$ 84,279	[1]	$ 98,975	[1]
Income from continuing operations before income taxes	654	1,256	848	797	62	813	720	596	3,555		2,191		6,044
Net Income	3,255	849	581	563	194	536	516	398	5,248		1,644		4,280
Net Income Attributable to Phillips 66	$ 3,198	$ 823	$ 550	$ 535	$ 163	$ 511	$ 496	$ 385	$ 5,106		$ 1,555		$ 4,227
Basic (in dollars per share)	$ 6.29	$ 1.60	$ 1.06	$ 1.02	$ 0.31	$ 0.97	$ 0.94	$ 0.72	$ 9.90		$ 2.94		$ 7.78
Diluted (in dollars per share)	$ 6.25	$ 1.60	$ 1.06	$ 1.02	$ 0.31	$ 0.96	$ 0.93	$ 0.72	$ 9.85		$ 2.92		$ 7.73
Tax Cuts and Jobs Act	$ 2,721								$ 2,721
[1]	Includes excise taxes on petroleum products sales: $13,054 million, $13,381 million, $13,780 million

Subsequent Event (Details)

Subsequent Event (Details) - USD ($)	Feb. 13, 2018	Feb. 14, 2018	Dec. 31, 2017
Share Repurchase Program And Additional Share Repurchases
Subsequent Event [Line Items]
Amount authorized for stock repurchase			$ 12,000,000,000
Subsequent Event | Purchase Agreement
Subsequent Event [Line Items]
Share authorized for repurchase (in shares)	35,000,000
Amount authorized for stock repurchase	$ 3,300,000,000
Initial price paid per share (usd per share)	$ 93.725
Cash and cash equivalents | Subsequent Event | Purchase Agreement
Subsequent Event [Line Items]
Share repurchase settlement amount		$ 1,900,000,000
Cash and cash equivalents | Subsequent Event | Commercial Paper | Purchase Agreement
Subsequent Event [Line Items]
Share repurchase settlement amount		$ 1,400,000,000