Valero Energy (VLO) 10-K 28 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
Entity Information [Line Items]
Entity Registrant Name	VALERO ENERGY CORP/TX
Entity Central Index Key	1,035,002
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 Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Filer Category	Large Accelerated Filer
Entity Public Float			$ 29.8
Entity Common Stock, Shares Outstanding		433,176,258

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Current assets:
Cash and temporary cash investments	$ 5,850	$ 4,816
Receivables, net	6,922	5,901
Inventories	6,384	5,709
Prepaid expenses and other	156	374
Total current assets	19,312	16,800
Property, plant, and equipment, at cost	40,010	37,733
Accumulated depreciation	(12,530)	(11,261)
Property, plant, and equipment, net	27,480	26,472
Deferred charges and other assets, net	3,366	2,901
Total assets	50,158	46,173
Current liabilities:
Current portion of debt and capital lease obligations	122	115
Accounts payable	8,348	6,357
Accrued expenses	712	694
Taxes other than income taxes payable	1,321	1,084
Income taxes payable	568	78
Total current liabilities	11,071	8,328
Debt and capital lease obligations, less current portion	8,750	7,886
Deferred income tax liabilities	4,708	7,361
Other long-term liabilities	2,729	1,744
Commitments and contingencies
Valero Energy Corporation stockholders’ equity:
Common stock, $0.01 par value; 1,200,000,000 shares authorized; 673,501,593 and 673,501,593 shares issued	7	7
Additional paid-in capital	7,039	7,088
Treasury stock, at cost; 239,603,534 and 222,000,024 common shares	(13,315)	(12,027)
Retained earnings	29,200	26,366
Accumulated other comprehensive loss	(940)	(1,410)
Total Valero Energy Corporation stockholders’ equity	21,991	20,024
Noncontrolling interests	909	830
Total equity	22,900	20,854
Total liabilities and equity	$ 50,158	$ 46,173

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2017	Dec. 31, 2016
Valero Energy Corporation stockholders’ equity:
Common stock, par value (in usd per share)	$ 0.01	$ 0.01
Common stock authorized (shares)	1,200,000,000	1,200,000,000
Common stock issued (shares)	673,501,593	673,501,593
Treasury stock (shares)	239,603,534	222,000,024

Consolidated Statements of Inco

Consolidated Statements of Income - USD ($) shares in Millions, $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating revenues	[1]	$ 93,980	$ 75,659	$ 87,804
Cost of sales:
Cost of materials and other		83,037	65,962	73,861
Operating expenses (excluding depreciation and amortization expense reflected below)		4,462	4,207	4,243
Depreciation and amortization expense		1,934	1,846	1,795
Lower of cost or market inventory valuation adjustment		0	(747)	790
Total cost of sales		89,433	71,268	80,689
Other operating expenses		61	0	0
General and administrative expenses (excluding depreciation and amortization expense reflected below)		835	715	710
Depreciation and amortization expense		52	48	47
Asset impairment loss		0	56	0
Operating income		3,599	3,572	6,358
Other income, net		76	56	46
Interest and debt expense, net of capitalized interest		(468)	(446)	(433)
Income before income tax expense (benefit)		3,207	3,182	5,971
Income tax expense (benefit)		(949)	765	1,870
Net income		4,156	2,417	4,101
Less: Net income attributable to noncontrolling interests		91	128	111
Net income attributable to Valero Energy Corporation stockholders		$ 4,065	$ 2,289	$ 3,990
Earnings per common share
Earnings per common share (in usd per share)		$ 9.17	$ 4.94	$ 8
Weighted-average common shares outstanding (in millions) (shares)		442	461	497
Earnings per common share – assuming dilution
Earnings per common share - assuming dilution (in usd per share)		$ 9.16	$ 4.94	$ 7.99
Weighted-average common shares outstanding – assuming dilution (in millions) (shares)		444	464	500
Dividends per common share (in dollars per share)		$ 2.8	$ 2.4	$ 1.7
[1]	Includes excise taxes on sales by certain of our international operations of $5,573 million, $5,493 million, and $5,980 million for the years ended December 31, 2017, 2016, and 2015.

Consolidated Statements of Inc5

Consolidated Statements of Income (Parenthetical) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Supplemental information:
Includes excise taxes on sales by certain of our international operations	$ 5,573	$ 5,493	$ 5,980

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net income	$ 4,156	$ 2,417	$ 4,101
Other comprehensive income (loss):
Foreign currency translation adjustment	514	(415)	(606)
Net gain (loss) on pension and other postretirement benefits	(65)	(98)	57
Other comprehensive income (loss) before income tax expense (benefit)	449	(513)	(549)
Income tax expense (benefit) related to items of other comprehensive income (loss)	(21)	(37)	17
Other comprehensive income (loss)	470	(476)	(566)
Comprehensive income	4,626	1,941	3,535
Less: Comprehensive income attributable to noncontrolling interests	91	129	111
Comprehensive income attributable to Valero Energy Corporation stockholders	$ 4,535	$ 1,812	$ 3,424

Consolidated Statements of Equi

Consolidated Statements of Equity - USD ($) $ in Millions	Total	Valero Energy Partners LP [Member]	Entities Other Than Valero Energy Partners LP [Member]	Parent [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Treasury Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Non-controlling Interests [Member]	Non-controlling Interests [Member]Valero Energy Partners LP [Member]	Non-controlling Interests [Member]Entities Other Than Valero Energy Partners LP [Member]
Beginning balance at Dec. 31, 2014	$ 21,244			$ 20,677	$ 7	$ 7,116	$ (8,125)	$ 22,046	$ (367)	$ 567
Increase (Decrease) in Equity Roll Forward
Net income	4,101			3,990				3,990		111
Dividends on common stock	(848)			(848)				(848)
Stock-based compensation expense	59			59		59
Tax deduction in excess of stock- based compensation expense	44			44		44
Transactions in connection with stock-based compensation plans	(162)			(162)		(155)	(7)
Stock purchases under purchase program	(2,667)			(2,667)			(2,667)
Issuance of Valero Energy Partners LP common units and contributions from noncontrolling interests		$ 189	$ 5								$ 189	$ 5
Distributions to noncontrolling interests	(45)									(45)
Other comprehensive income (loss)	(566)			(566)					(566)	0
Ending balance at Dec. 31, 2015	21,354			20,527	7	7,064	(10,799)	25,188	(933)	827
Increase (Decrease) in Equity Roll Forward
Net income	2,417			2,289				2,289		128
Dividends on common stock	(1,111)			(1,111)				(1,111)
Stock-based compensation expense	68			68		68
Transactions in connection with stock-based compensation plans	(55)			(55)		(89)	34
Stock purchases under purchase program	(1,262)			(1,262)			(1,262)
Issuance of Valero Energy Partners LP common units and contributions from noncontrolling interests		11									11
Distributions to noncontrolling interests	(65)									(65)
Other	(27)			45		45		0		(72)
Other comprehensive income (loss)	(476)			(477)					(477)	1
Ending balance at Dec. 31, 2016	20,854			20,024	7	7,088	(12,027)	26,366	(1,410)	830
Increase (Decrease) in Equity Roll Forward
Net income	4,156			4,065				4,065		91
Dividends on common stock	(1,242)			(1,242)				(1,242)
Stock-based compensation expense	68			68		68
Transactions in connection with stock-based compensation plans	(63)			(63)		(82)	19
Stock purchases under purchase program	(1,307)			(1,307)			(1,307)
Issuance of Valero Energy Partners LP common units and contributions from noncontrolling interests		$ 33	$ 30								$ 33	$ 30
Distributions to noncontrolling interests	(67)									(67)
Other	(32)			(24)		(35)		11		(8)
Other comprehensive income (loss)	470			470					470	0
Ending balance at Dec. 31, 2017	$ 22,900			$ 21,991	$ 7	$ 7,039	$ (13,315)	$ 29,200	$ (940)	$ 909

Consolidated Statements of Cash

Consolidated Statements 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	$ 4,156	$ 2,417	$ 4,101
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization expense	1,986	1,894	1,842
Lower of cost or market inventory valuation adjustment	0	(747)	790
Asset impairment loss	0	56	0
Deferred income tax expense (benefit)	(2,543)	230	165
Changes in current assets and current liabilities	1,289	976	(1,306)
Changes in deferred charges and credits and other operating activities, net	594	(6)	19
Net cash provided by operating activities	5,482	4,820	5,611
Cash flows from investing activities:
Capital expenditures	(1,353)	(1,278)	(1,618)
Deferred turnaround and catalyst costs	(523)	(718)	(673)
Investments in joint ventures	(406)	(4)	(141)
Acquisition of undivided interest	(72)	0	0
Capital expenditures of certain variable interest entities	(26)	0	0
Other investing activities, net	(2)	(6)	(55)
Net cash used in investing activities	(2,382)	(2,006)	(2,487)
Cash flows from financing activities:
Proceeds from debt issuances or borrowings	380	2,153	1,446
Repayments of debt and capital lease obligations	(21)	(1,475)	(513)
Proceeds from the exercise of stock options	10	6	34
Purchase of common stock for treasury	(1,372)	(1,336)	(2,838)
Common stock dividends	(1,242)	(1,111)	(848)
Proceeds from issuance of Valero Energy Partners LP common units	36	10	189
Contributions from noncontrolling interests	30	0	5
Distributions to noncontrolling interests	(67)	(65)	(45)
Other financing activities, net	(26)	(194)	25
Net cash used in financing activities	(2,272)	(2,012)	(2,545)
Effect of foreign exchange rate changes on cash	206	(100)	(154)
Net increase in cash and temporary cash investments	1,034	702	425
Cash and temporary cash investments at beginning of year	4,816	4,114	3,689
Cash and temporary cash investments at end of year	$ 5,850	$ 4,816	$ 4,114

Description of Business, Basis

Description of Business, Basis of Presentation, and Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
DESCRIPTION OF BUSINESS, BASIS OF PRESENTATION, AND SIGNIFICANT ACCOUNTING POLICIES	1. DESCRIPTION OF BUSINESS, BASIS OF PRESENTATION, AND SIGNIFICANT ACCOUNTING POLICIES Description of Business As used in this report, the terms “Valero,” “we,” “us,” or “our” refer to Valero Energy Corporation, one or more of its consolidated subsidiaries, or all of them taken as a whole. We are an independent petroleum refiner and ethanol producer. We own 15 petroleum refineries located in the United States (U.S.), Canada, and the United Kingdom (U.K.) with a combined throughput capacity of approximately 3.1 million barrels per day as of December 31, 2017 . We sell our refined petroleum products in both the wholesale rack and bulk markets, and approximately 7,400 outlets carry our brand names in the U.S., Canada, the U.K., and Ireland. Most of our logistics assets support our refining operations, and some of these assets are owned by Valero Energy Partners LP (VLP). See Note 11 for further discussion about VLP. We also own 11 ethanol plants in the Mid-Continent region of the U.S. with a combined production capacity of approximately 1.45 billion gallons per year as of December 31, 2017 . We sell our ethanol in the wholesale bulk market, and some of our logistics assets support our ethanol operations. Basis of Presentation General These consolidated financial statements were prepared in accordance with U.S. generally accepted accounting principles (GAAP) and with the rules and regulations of the U.S. Securities and Exchange Commission (SEC). Reclassifications Effective January 1, 2017, we revised our reportable segments to reflect a new reportable segment — VLP. The results of the VLP segment include the results of VLP, our majority-owned master limited partnership. Our prior period segment information has been retrospectively adjusted to reflect our current segment presentation. See Note 16 for additional information. Certain prior year amounts have been reclassified to conform to the 2017 presentation. The changes were primarily due to the separate presentation of depreciation and amortization expense related to operating expenses and general and administrative expenses. Significant Accounting Policies Principles of Consolidation These financial statements include those of Valero, our wholly owned subsidiaries, and variable interest entities (VIEs) in which we have a controlling interest. Our VIEs are described in Note 11 . The ownership interests held by others in the VIEs are recorded as noncontrolling interests. Intercompany items and transactions have been eliminated in consolidation. Investments in less than wholly owned entities where we have significant influence are accounted for using the equity method. Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires us to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates. On an ongoing basis, we review our estimates based on currently available information. Changes in facts and circumstances may result in revised estimates. Temporary Cash Investments Our temporary cash investments are highly liquid, low-risk debt instruments that have a maturity of three months or less when acquired. Receivables Trade receivables are carried at original invoice amount. We maintain an allowance for doubtful accounts, which is adjusted based on management’s assessment of our customers’ historical collection experience, known credit risks, and industry and economic conditions. Inventories The cost of refinery feedstocks, refined petroleum products, and grain and ethanol inventories is determined under the last-in, first-out (LIFO) method using the dollar-value LIFO approach, with any increments valued based on average purchase prices during the year. Our LIFO inventories are carried at the lower of cost or market. The cost of products purchased for resale and the cost of materials and supplies are determined principally under the weighted-average cost method. Our non-LIFO inventories are carried at the lower of cost or net realizable value. If the aggregate market value of our LIFO inventories or the aggregate net realizable value of our non-LIFO inventories is less than the related aggregate cost, we recognize a loss for the difference in our statements of income. Property, Plant, and Equipment The cost of property, plant, and equipment (property assets) purchased or constructed, including betterments of property assets, is capitalized. However, the cost of repairs to and normal maintenance of property assets is expensed as incurred. Betterments of property assets are those that extend the useful life, increase the capacity or improve the operating efficiency of the asset, or improve the safety of our operations. The cost of property assets constructed includes interest and certain overhead costs allocable to the construction activities. Our operations, especially those of our refining segment, are highly capital intensive. Each of our refineries comprises a large base of property assets, consisting of a series of interconnected, highly integrated and interdependent crude oil processing facilities and supporting logistical infrastructure (Units), and these Units are continuously improved. Improvements consist of the addition of new Units and betterments of existing Units. We plan for these improvements by developing a multi-year capital program that is updated and revised based on changing internal and external factors. Depreciation of property assets used in our refining segment is recorded on a straight-line basis over the estimated useful lives of these assets primarily using the composite method of depreciation. We maintain a separate composite group of property assets for each of our refineries. We estimate the useful life of each group based on an evaluation of the property assets comprising the group, and such evaluations consist of, but are not limited to, the physical inspection of the assets to determine their condition, consideration of the manner in which the assets are maintained, assessment of the need to replace assets, and evaluation of the manner in which improvements impact the useful life of the group. The estimated useful lives of our composite groups range primarily from 25 to 30 years. Under the composite method of depreciation, the cost of an improvement is added to the composite group to which it relates and is depreciated over that group’s estimated useful life. We design improvements to our refineries in accordance with engineering specifications, design standards, and practices accepted in our industry, and these improvements have design lives consistent with our estimated useful lives. Therefore, we believe the use of the group life to depreciate the cost of improvements made to the group is reasonable because the estimated useful life of each improvement is consistent with that of the group. Also under the composite method of depreciation, the historical cost of a minor property asset (net of salvage value) that is retired or replaced is charged to accumulated depreciation and no gain or loss is recognized in income. However, a gain or loss is recognized in income for a major property asset that is retired, replaced, sold, or for an abnormal disposition of a property asset (primarily involuntary conversions). Gains and losses are reflected in depreciation and amortization expense, unless such amounts are reported separately due to materiality. Depreciation of property assets used in our ethanol segment is recorded on a straight-line basis over the estimated useful lives of the related assets. Leasehold improvements are amortized on a straight-line basis over the shorter of the lease term or the estimated useful life of the related asset. Assets acquired under capital leases are amortized on a straight-line basis over (i) the lease term if transfer of ownership does not occur at the end of the lease term or (ii) the estimated useful life of the asset if transfer of ownership does occur at the end of the lease term. Deferred Charges and Other Assets “Deferred charges and other assets, net” primarily include the following: • turnaround costs, which are incurred in connection with planned major maintenance activities at our refineries and ethanol plants and which are deferred when incurred and amortized on a straight-line basis over the period of time estimated to lapse until the next turnaround occurs; • fixed-bed catalyst costs, representing the cost of catalyst that is changed out at periodic intervals when the quality of the catalyst has deteriorated beyond its prescribed function, which are deferred when incurred and amortized on a straight-line basis over the estimated useful life of the specific catalyst; • income taxes receivable; • investments in joint ventures accounted for under the equity method; and • intangible assets. Impairment of Assets Long-lived assets are tested for recoverability whenever events or changes in circumstances indicate that the carrying amount of the asset may not be recoverable. A long-lived asset is not recoverable if its carrying amount exceeds the sum of the undiscounted cash flows expected to result from its use and eventual disposition. If a long-lived asset is not recoverable, an impairment loss is recognized for the amount by which the carrying amount of the long-lived asset exceeds its fair value, with fair value determined based on discounted estimated net cash flows or other appropriate methods. We evaluate our equity method investments for impairment when there is evidence that we may not be able to recover the carrying amount of our investments or the investee is unable to sustain an earnings capacity that justifies the carrying amount. A loss in the value of an investment that is other than a temporary decline is recognized currently in income, and is based on the difference between the estimated current fair value of the investment and its carrying amount. Environmental Matters Liabilities for future remediation costs are recorded when environmental assessments and/or remedial efforts are probable and the costs can be reasonably estimated. Other than for assessments, the timing and magnitude of these accruals generally are based on the completion of investigations or other studies or a commitment to a formal plan of action. Amounts recorded for environmental liabilities have not been reduced by possible recoveries from third parties and have not been measured on a discounted basis. Asset Retirement Obligations We record a liability, which is referred to as an asset retirement obligation, at fair value for the estimated cost to retire a tangible long-lived asset at the time we incur that liability, which is generally when the asset is purchased, constructed, or leased. We record the liability when we have a legal obligation to incur costs to retire the asset and when a reasonable estimate of the fair value of the liability can be made. If a reasonable estimate cannot be made at the time the liability is incurred, we record the liability when sufficient information is available to estimate the liability’s fair value. We have asset retirement obligations with respect to certain of our refinery assets due to various legal obligations to clean and/or dispose of various component parts of each refinery at the time they are retired. However, these component parts can be used for extended and indeterminate periods of time as long as they are properly maintained and/or upgraded. In addition, we have asset retirement obligations with respect to our ethanol plants and certain of our logistics assets that require us to perform under law or contract once the asset is retired from service. It is our practice and current intent to maintain all our assets and continue making improvements to those assets based on technological advances. As a result, we believe that our refineries, ethanol plants, and logistics assets have indeterminate lives for purposes of estimating asset retirement obligations because dates or ranges of dates upon which we would retire such assets cannot reasonably be estimated at this time. We will recognize a liability at such time when sufficient information exists to estimate a date or range of potential settlement dates that is needed to employ a present value technique to estimate fair value. Foreign Currency Translation The functional currency of each of our international operations is the respective local currency, which includes the Canadian dollar, the pound sterling, the euro, and the Mexican peso. Balance sheet accounts are translated into U.S. dollars using exchange rates in effect as of the balance sheet date. Revenue and expense accounts are translated using the weighted-average exchange rates during the year presented. Foreign currency translation adjustments are recorded as a component of accumulated other comprehensive loss. Revenue Recognition Revenues for products sold by our refining and ethanol segments are recorded upon delivery and transfer of title to the products to our customers and when payment has either been received or collection is reasonably assured. Our VLP segment generates revenues by providing fee-based transportation and terminaling services to transport and store crude oil and refined petroleum products using its pipelines and terminals under long-term commercial agreements. VLP segment revenues are recognized upon completion of the transportation or terminaling service. However, because VLP segment revenues are intersegment revenues with our refining segment, all VLP segment revenues are eliminated in consolidation. We present excise taxes on sales by certain of our international operations on a gross basis in revenues. The amount of such taxes is provided in supplemental information in a footnote on the statements of income. All other excise taxes are presented on a net basis. We enter into certain purchase and sale arrangements with the same counterparty that are deemed to be made in contemplation of one another. We combine these transactions and present the net effect in cost of materials and other. We also enter into refined petroleum product exchange transactions to fulfill sales contracts with our customers by accessing refined petroleum products in markets where we do not operate our own refineries. These refined petroleum product exchanges are accounted for as exchanges of non-monetary assets, and no revenues are recorded on these transactions. Cost Classifications “Cost of materials and other” primarily includes the cost of materials that are a component of our products sold. These costs include (i) the direct cost of materials (such as crude oil and other refinery feedstocks, refined petroleum products and blendstocks, and ethanol feedstocks and products) that are a component of our products sold; (ii) costs related to the delivery (such as shipping and handling costs) of products sold; (iii) costs related to our environmental credit obligations to comply with various governmental and regulatory programs (such as the cost of Renewable Identification Numbers (RINs) as required by the U.S. Environmental Protection Agency’s (EPA) Renewable Fuel Standard and emission credits under various cap-and-trade systems, as defined in Note 18 ); (iv) gains and losses on our commodity derivative instruments; and (v) certain excise taxes. “Operating expenses (excluding depreciation and amortization expense)” include costs to operate our refineries, ethanol plants, and logistics assets, except for depreciation and amortization expense. These costs primarily include employee-related expenses, energy and utility costs, catalysts and chemical costs, and repair and maintenance expenses. “Depreciation and amortization expense” associated with our operations is separately presented in our statement of income as a component of cost of sales and general and administrative expenses and is disclosed by reportable segment in Note 16 . “Other operating expenses” include costs, if any, incurred by our reportable segments that are not associated with our cost of sales. Environmental Compliance Program Costs We purchase credits in the open market to meet our obligations under various environmental compliance programs. We purchase biofuel credits (primarily RINs in the U.S.) to comply with government regulations that require us to blend a certain percentage of biofuels into the products we produce. To the degree that we are unable to blend biofuels at the required percentage, we must purchase biofuel credits to meet our obligation. We purchase greenhouse gas (GHG) emission credits to comply with government regulations concerning various GHG emission programs, including cap-and-trade systems. These programs are further described in Note 19 under “Environmental Compliance Program Price Risk.” The costs of purchased biofuel credits and GHG emission credits are charged to cost of materials and other as such credits are needed to satisfy our obligation. To the extent we have not purchased enough credits to satisfy our obligation as of the balance sheet date, we charge cost of materials and other for such deficiency based on the market price of the credits as of the balance sheet date, and we record a liability for our obligation to purchase those credits. See Note 18 for disclosure of our fair value liability. Stock-Based Compensation Compensation expense for our share-based compensation plans is based on the fair value of the awards granted and is recognized in income on a straight-line basis over the shorter of (a) the requisite service period of each award or (b) the period from the grant date to the date retirement eligibility is achieved if that date is expected to occur during the vesting period established in the award. Income Taxes Income taxes are accounted for under the asset and liability method. Under this 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 amounts are measured using enacted tax rates expected to apply to taxable income in the year those temporary differences are expected to be recovered or settled. Deferred tax assets are reduced by unrecognized tax benefits, if such items may be available to offset the unrecognized tax benefit. We have elected to classify any interest expense and penalties related to the underpayment of income taxes in income tax expense. Earnings per Common Share Earnings per common share is computed by dividing net income attributable to Valero stockholders by the weighted-average number of common shares outstanding for the year. Participating share-based payment awards, including shares of restricted stock granted under certain of our stock-based compensation plans, are included in the computation of basic earnings per share using the two-class method. Earnings per common share – assuming dilution reflects the potential dilution arising from our outstanding stock options and nonvested shares granted to employees in connection with our stock-based compensation plans. Potentially dilutive securities are excluded from the computation of earnings per common share – assuming dilution when the effect of including such shares would be antidilutive. Financial Instruments Our financial instruments include cash and temporary cash investments, receivables, payables, debt, capital lease obligations, commodity derivative contracts, and foreign currency derivative contracts. The estimated fair values of these financial instruments approximate their carrying amounts, except for certain debt as discussed in Note 18 . Derivatives and Hedging All derivative instruments, not designated as normal purchases or sales, are recorded in the balance sheet as either assets or liabilities measured at their fair values with changes in fair value recognized currently in income. To manage commodity price risk, we use economic hedges, which are not designated as fair value or cash flow hedges, and we use fair value and cash flow hedges from time to time. We also enter into certain commodity derivative instruments for trading purposes. The cash flow effects of all of our derivative instruments are reflected in operating activities in the statements of cash flows. Business Combinations Effective January 1, 2017, we adopted the provisions of Accounting Standards Update (ASU) No. 2017-01, “Business Combinations (Topic 805),” that was issued by the Financial Accounting Standards Board (FASB) in January 2017. This ASU provides a more robust framework to evaluate whether transactions should be accounted for as acquisitions (dispositions) of assets or businesses. Our adoption of this ASU did not affect our financial position or results of operations. However, more of our future acquisitions may be accounted for as acquisitions of assets in accordance with this ASU. Accounting Pronouncements Adopted on January 1, 2018 ASU No. 2014-09 In May 2014, the FASB issued ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606),” to clarify the principles for recognizing revenue. This new standard is effective for annual reporting periods beginning after December 15, 2017, including interim reporting periods within those annual periods. We adopted this standard on January 1, 2018 and it will not materially change the amount or timing of revenues recognized by us, nor will it materially affect our financial position. The majority of our revenues are generated from the sale of refined petroleum products and ethanol. These revenues are largely based on the current spot (market) prices of the products sold, which represent consideration specifically allocable to the products being sold on a given day, and we recognize those revenues upon delivery and transfer of title to the products to our customers. The time at which delivery and transfer of title occurs is the point when our control of the products is transferred to our customers and when our performance obligation to our customers is fulfilled. We adopted this new standard on January 1, 2018 using the modified retrospective method as permitted by the standard. Under this method, the cumulative effect of initially applying the standard is recognized as an adjustment to the opening balance of retained earnings, and revenues reported in the periods prior to the date of adoption are not changed. Because the adoption of this standard did not materially impact the manner in which we recognize revenues, we will not make such an adjustment to retained earnings. We continue to develop our revenue disclosures and have enhanced our accounting systems to enable the preparation of such disclosures. ASU No. 2016-01 In January 2016, the FASB issued ASU No. 2016-01, “Financial Instruments—Overall (Subtopic 825-10),” to enhance the reporting model for financial instruments regarding certain aspects of recognition, measurement, presentation, and disclosure. The provisions of this ASU are effective for annual reporting periods beginning after December 15, 2017, and interim reporting periods within those annual periods. This ASU is to be applied using a cumulative-effect adjustment to the balance sheet as of the beginning of the year of adoption. The adoption of this ASU effective January 1, 2018 did not affect our financial position nor will it affect our results of operations, but it will result in revised disclosures. ASU No. 2017-07 In March 2017, the FASB issued ASU No. 2017-07, “Compensation—Retirement Benefits (Topic 715),” which requires employers to report the service cost component of net periodic pension cost and net periodic postretirement benefit cost in the same line item as other compensation costs arising from services rendered by the pertinent employees during the period. It also requires the other components of net periodic pension cost and net periodic postretirement benefit cost (non-service cost components) to be presented in the income statement separately from the service cost component and outside a subtotal of income from operations. This ASU is to be applied retrospectively for income statement items and prospectively for any capitalized benefit costs. The adoption of this ASU effective January 1, 2018 did not affect our financial position or results of operations, but will result in the reclassification of the non-service cost components from operating expenses (excluding depreciation and amortization) and general and administrative expenses (excluding depreciation and amortization) to “other income, net.” ASU No. 2017-09 In May 2017, the FASB issued ASU No. 2017-09, “Compensation—Stock Compensation (Topic 718),” to reduce diversity in practice, as well as reduce cost and complexity regarding a change to the terms or conditions of a share-based payment award. The adoption of this ASU effective January 1, 2018 did not have an immediate effect on our financial position or results of operations as it will be applied prospectively to an award modified on or after adoption. Accounting Pronouncements Not Yet Adopted ASU No. 2016-02 In February 2016, the FASB issued ASU No. 2016-02, “Leases (Topic 842),” to increase the transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. This new standard is effective for annual reporting periods beginning after December 15, 2018, and interim reporting periods within those annual periods, with early adoption permitted. We will adopt this new standard on January 1, 2019, and we expect to use the modified retrospective method of adoption. We are enhancing our contracting and lease evaluation systems and related processes, and we are developing a new lease accounting system to capture our leases and support the required disclosures. During 2018, we will continue to monitor the adoption process to ensure compliance with accounting and disclosure requirements. We also continue the integration of our lease accounting system with our general ledger, and we will make modifications to the related procurement and payment processes. We anticipate this standard will have a material impact on our financial position by increasing our assets and liabilities by equal amounts through the recognition of right-of-use assets and lease liabilities for our operating leases. However, we do not expect adoption to have a material impact on our results of operations or liquidity. We expect our accounting for capital leases to remain substantially unchanged. ASU No. 2017-12 In August 2017, the FASB issued ASU No. 2017-12, “Derivatives and Hedging (Topic 815),” to improve and simplify accounting guidance for hedge accounting. The provisions of this ASU are effective for annual reporting periods beginning after December 15, 2018, and interim reporting periods within those annual periods, with early adoption permitted. We use economic hedges to manage commodity price risk; however, we have not designated these hedges as fair value or cash flow hedges. As a result, the adoption of this ASU effective January 1, 2019 is not expected to affect our financial position or results of operations. ASU No. 2018-02 In February 2018, the FASB issued ASU No. 2018-02, “Income Statement—Reporting Comprehensive Income (Topic 220),” which allows for the reclassification from accumulated other comprehensive income to retained earnings for the stranded tax effects resulting from the Tax Cuts and Jobs Act of 2017 (Tax Reform), as discussed in Note 14 . The provisions of this ASU are effective for annual reporting periods beginning after December 15, 2018, and interim reporting periods within those annual periods, with early adoption permitted. This ASU shall be applied at the beginning of the annual or interim period of adoption or retrospectively to each period in which the income tax effects of Tax Reform affects the items remaining in accumulated other comprehensive income. The adoption of this ASU is not expected to affect our financial position or results of operations, but will result in the reclassification of the income tax effects of Tax Reform and additional disclosures.

Aruba Disposition

Aruba Disposition	12 Months Ended
	Dec. 31, 2017
Discontinued Operations and Disposal Groups [Abstract]
ARUBA DISPOSITION	2. ARUBA DISPOSITION Effective October 1, 2016, we (i) transferred ownership of all of our assets in Aruba, other than certain hydrocarbon inventories and working capital, to Refineria di Aruba N.V., an entity wholly-owned by the Government of Aruba (GOA), (ii) settled our obligations under various agreements with the GOA, including agreements that required us to dismantle our leasehold improvements under certain conditions, and (iii) sold the working capital of our Aruba operations, including hydrocarbon inventories, to the GOA and CITGO (defined below). We refer to this transaction as the “Aruba Disposition.” The agreements associated with the Aruba Disposition were finalized in September 2016, including approval of such agreements by the Aruba Parliament. We no longer own any assets or have any operations in Aruba. In September 2016 and in connection with the Aruba Disposition, our U.S. subsidiaries were unable to collect outstanding debt obligations owed to them by our Aruba subsidiaries, which resulted in the recognition by us of an income tax benefit in the U.S. of $42 million during the year ended December 31, 2016. We had no income tax effect in Aruba from the cancellation of debt or other effects of the Aruba Disposition because of net operating loss carryforwards associated with our operations in Aruba against which we had previously recorded a full valuation allowance. Prior to the Aruba Disposition, we recognized an asset impairment loss of $56 million in June 2016 representing all of the remaining carrying value of our long-lived assets in Aruba. These assets were primarily related to our crude oil and refined petroleum products terminal and transshipment facility in Aruba (collectively, the Aruba Terminal), which were included in our refining segment. We recognized the impairment loss at that time because we concluded that it was more likely than not that we would ultimately transfer ownership of these assets to the GOA as a result of agreements entered into in June 2016 between the GOA, CITGO Aruba Refining N.V. (CAR), and CITGO Petroleum Corporation (together with CAR and certain other affiliates, collectively, CITGO) providing for, among other things, the GOA’s lease of those assets to CITGO. (See Note 18 for disclosure related to the method to determine fair value.)

Receivables

Receivables	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
RECEIVABLES	3. RECEIVABLES Receivables consisted of the following (in millions): December 31, 2017 2016 Accounts receivable $ 6,786 $ 5,687 Commodity derivative and foreign currency contract receivables 102 129 Other receivables 67 117 6,955 5,933 Allowance for doubtful accounts (33 ) (32 ) Receivables, net $ 6,922 $ 5,901 There were no significant changes in our allowance for doubtful accounts during the years ended December 31, 2017 , 2016 , and 2015 .

Inventories

Inventories	12 Months Ended
	Dec. 31, 2017
Inventory Disclosure [Abstract]
INVENTORIES	4. INVENTORIES Inventories consisted of the following (in millions): December 31, 2017 2016 Refinery feedstocks $ 2,427 $ 2,068 Refined petroleum products and blendstocks 3,459 3,153 Ethanol feedstocks and products 242 238 Materials and supplies 256 250 Inventories $ 6,384 $ 5,709 As of December 31, 2017 and 2016 , the replacement cost (market value) of LIFO inventories exceeded their LIFO carrying amounts by $3.0 billion and $1.9 billion , respectively. As of December 31, 2017 and 2016 , our non-LIFO inventories accounted for $1.0 billion and $641 million , respectively, of our total inventories. During the year ended December 31, 2016 , we recorded a change in our lower of cost or market inventory valuation reserve that resulted in a net benefit to our results of operations of $747 million , and we had a liquidation of LIFO inventory layers that increased cost of sales by $120 million . During the year ended December 31, 2015 , we recorded a lower of cost or market inventory valuation adjustment that resulted in a net charge to our results of operations of $790 million in order to state our inventories at market as of December 31, 2015 .

Property, Plant, and Equipment

Property, Plant, and Equipment	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
PROPERTY, PLANT, AND EQUIPMENT	5. PROPERTY, PLANT, AND EQUIPMENT Major classes of property, plant, and equipment, including assets held under capital leases, consisted of the following (in millions): December 31, 2017 2016 Land $ 411 $ 400 Crude oil processing facilities 30,109 29,754 Transportation and terminaling facilities 4,335 3,692 Grain processing equipment 903 855 Administrative buildings 910 838 Other 2,068 1,464 Construction in progress 1,274 730 Property, plant, and equipment, at cost 40,010 37,733 Accumulated depreciation (12,530 ) (11,261 ) Property, plant, and equipment, net $ 27,480 $ 26,472 We have various assets under capital leases that primarily support our refining operations totaling $635 million and $118 million as of December 31, 2017 and 2016 , respectively. Accumulated amortization on assets under capital leases was $72 million and $45 million as of December 31, 2017 and 2016 , respectively. Depreciation expense was $1.3 billion for each of the years in the three-year period ended December 31, 2017 .

Deferred Charges and Other Asse

Deferred Charges and Other Assets	12 Months Ended
	Dec. 31, 2017
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
DEFERRED CHARGES AND OTHER ASSETS	6. DEFERRED CHARGES AND OTHER ASSETS “Deferred charges and other assets, net” consisted of the following (in millions): December 31, 2017 2016 Deferred turnaround and catalyst costs, net $ 1,520 $ 1,614 Income taxes receivable 673 447 Investments in joint ventures 530 201 Intangible assets, net 142 148 Other 501 491 Deferred charges and other assets, net $ 3,366 $ 2,901 Amortization expense for the deferred charges and other assets shown above was $650 million , $575 million , and $542 million for the years ended December 31, 2017 , 2016 , and 2015 , respectively.

Accrued Expenses and Other Long

Accrued Expenses and Other Long-Term Liabilities	12 Months Ended
	Dec. 31, 2017
Accrued Expenses and Other Long-Term Liabilities [Abstract]
ACCRUED EXPENSES AND OTHER LONG-TERM LIABILITIES	7. ACCRUED EXPENSES AND OTHER LONG-TERM LIABILITIES Accrued expenses and other long-term liabilities consisted of the following (in millions): Accrued Expenses Other Long- Term Liabilities December 31, December 31, 2017 2016 2017 2016 Defined benefit plan liabilities (see Note 12) $ 33 $ 32 $ 776 $ 742 Wage and other employee-related liabilities 278 225 111 103 Uncertain income tax position liabilities (see Note 14) — — 723 465 Repatriation tax liability (see Note 14) — — 597 — Environmental liabilities 30 29 232 223 Environmental credit obligations (see Note 18) 152 214 — — Accrued interest expense 105 104 — — Other accrued liabilities 114 90 290 211 Accrued expenses and other long-term liabilities $ 712 $ 694 $ 2,729 $ 1,744 There were no significant changes in our environmental liabilities during each of the years in the three-year period ended December 31, 2017 .

Debt and Capital Lease Obligati

Debt and Capital Lease Obligations	12 Months Ended
	Dec. 31, 2017
Debt and Capital Lease Obligations [Abstract]
DEBT AND CAPITAL LEASE OBLIGATIONS	8. DEBT AND CAPITAL LEASE OBLIGATIONS Debt, at stated values, and capital lease obligations consisted of the following (in millions): Final Maturity December 31, 2017 2016 Bank credit facilities: Valero Revolver 2020 $ — $ — VLP Revolver 2020 410 30 Canadian Revolver 2018 — — Accounts receivable sales facility 2018 100 100 Non-bank debt: Valero Senior Notes 6.625% 2037 1,500 1,500 3.4% 2026 1,250 1,250 6.125% 2020 850 850 9.375% 2019 750 750 7.5% 2032 750 750 4.9% 2045 650 650 3.65% 2025 600 600 10.5% 2039 250 250 8.75% 2030 200 200 7.45% 2097 100 100 6.75% 2037 24 24 VLP Senior Notes, 4.375% 2026 500 500 Gulf Opportunity Zone Revenue Bonds, Series 2010, 4.0% 2040 300 300 Debenture, 7.65% 2026 100 100 Other debt 2023 49 51 Net unamortized debt issuance costs and other (73 ) (79 ) Total debt 8,310 7,926 Capital lease obligations 562 75 Total debt and capital lease obligations 8,872 8,001 Less current portion 122 115 Debt and capital lease obligations, less current portion $ 8,750 $ 7,886 Bank Credit Facilities Valero Revolver We have a $3 billion revolving credit facility (the Valero Revolver) with a group of financial institution lenders that matures in November 2020 . We have the option to increase the aggregate commitments under the Valero Revolver to $4.5 billion and we may request two additional one -year extensions, subject to certain conditions. The Valero Revolver also provides for the issuance of letters of credit of up to $2.0 billion . Outstanding borrowings under the Valero Revolver bear interest, at our option, at either (a) the adjusted LIBO rate (as defined in the Valero Revolver) for the applicable interest period in effect from time to time plus the applicable margin or (b) the alternate base rate (as defined in the Valero Revolver) plus the applicable margin. The Valero Revolver also requires payments for customary fees, including facility fees, letter of credit participation fees, and administrative agent fees. The interest rate and facility fees under the Valero Revolver are subject to adjustment based upon the credit ratings assigned to our senior unsecured debt. We had no borrowings or repayments under the Valero Revolver during the years ended December 31, 2017 , 2016 , and 2015 . VLP Revolver VLP has a $750 million senior unsecured revolving credit facility (the VLP Revolver) with a group of lenders that matures in November 2020 . The VLP Revolver is available only to the operations of VLP, and creditors of VLP do not have recourse against Valero. VLP has the option to increase the aggregate commitments under the VLP Revolver to $1.0 billion and VLP may request two additional one -year extensions, subject to certain conditions. VLP may terminate the VLP Revolver with notice to the lenders of at least three business days prior to termination. The VLP Revolver also provides for the issuance of letters of credit of up to $100 million . As a result of VLP obtaining an investment grade rating with respect to its issuance of senior notes in December 2016 , VLP’s directly owned subsidiary, Valero Partners Operating Co. LLC, was released of its guarantee under the VLP Revolver. Outstanding borrowings under the VLP Revolver bear interest, at VLP’s option, at either (a) the adjusted LIBO rate (as defined in the VLP Revolver) for the applicable interest period in effect from time to time plus the applicable margin or (b) the alternate base rate (as defined in the VLP Revolver) plus the applicable margin. As of December 31, 2017 and 2016 , the variable rate was 2.875 percent and 2.3125 percent, respectively. The VLP Revolver requires payments for customary fees, including commitment fees, letter of credit participation fees, and administrative agent fees. The VLP Revolver contains certain restrictive covenants, including a covenant that requires VLP to maintain a ratio of total debt to EBITDA (as defined in the VLP Revolver) for the prior four fiscal quarters of not greater than 5.0 to 1.0 as of the last day of each fiscal quarter, and limitations on VLP’s ability to pay distributions to its unitholders. During the year ended December 31, 2017 , VLP borrowed $118 million and $262 million under the VLP Revolver in connection with VLP’s acquisitions from us of Parkway Pipeline LLC and Valero Partners Port Arthur, LLC, respectively, and had no repayments under the VLP Revolver. During the year ended December 31, 2016 , VLP borrowed $139 million and $210 million under the VLP Revolver in connection with VLP’s acquisitions from us of the McKee Terminal Services Business and the Meraux and Three Rivers Terminal Services Business, respectively, and repaid $494 million on the VLP Revolver. During the year ended December 31, 2015 , VLP borrowed $200 million under the VLP Revolver in connection with VLP’s acquisition from us of the Houston and St. Charles Terminal Services Business and repaid $25 million on the VLP Revolver. Canadian Revolver In October 2017 , one of our Canadian subsidiaries amended its committed revolving credit facility (the Canadian Revolver) to increase the borrowing capacity from C$25 million to C$75 million under which it may borrow and obtain letters of credit and to extend the maturity date from November 2017 to November 2018 . We had no borrowings or repayments under the Canadian Revolver during the years ended December 31, 2017 , 2016 , and 2015 . Accounts Receivable Sales Facility We have an accounts receivable sales facility with a group of third-party entities and financial institutions to sell up to $1.3 billion of eligible trade receivables on a revolving basis. In July 2017, we amended our agreement to extend the maturity date to July 2018 . Proceeds from the sale of receivables under this facility are reflected as debt. Under this program, one of our marketing subsidiaries (Valero Marketing) sells eligible receivables, without recourse, to another of our subsidiaries (Valero Capital), whereupon the receivables are no longer owned by Valero Marketing. Valero Capital, in turn, sells an undivided percentage ownership interest in the eligible receivables, without recourse, to the third-party entities and financial institutions. To the extent that Valero Capital retains an ownership interest in the receivables it has purchased from Valero Marketing, such interest is included in our financial statements solely as a result of the consolidation of the financial statements of Valero Capital with those of Valero Energy Corporation; the receivables are not available to satisfy the claims of the creditors of Valero Marketing or Valero Energy Corporation. As of December 31, 2017 and 2016 , $2.3 billion and $2.0 billion , respectively, of our accounts receivable composed the designated pool of accounts receivable included in the program. All amounts outstanding under the accounts receivable sales facility are reflected as debt on our balance sheets and proceeds and repayments are reflected as cash flows from financing activities on the statements of cash flows. As of December 31, 2017 and 2016 , the variable interest rate on the accounts receivable sales facility was 2.0387 percent and 1.3422 percent, respectively. During the years ended December 31, 2017 , 2016 , and 2015 , we had no proceeds from or repayments under the accounts receivable sales facility. Summary of Credit Facilities We had outstanding borrowings, letters of credit issued, and availability under our credit facilities as follows (in millions): December 31, 2017 Facility Amount Maturity Date Outstanding Borrowings Letters of Credit Issued Availability Committed facilities: Valero Revolver $ 3,000 November 2020 $ — $ 54 $ 2,946 VLP Revolver $ 750 November 2020 $ 410 $ — $ 340 Canadian Revolver C$ 75 November 2018 C$ — C$ 10 C$ 65 Accounts receivable sales facility $ 1,300 July 2018 $ 100 n/a $ 1,200 Letter of credit facility $ 100 November 2018 n/a $ — $ 100 Uncommitted facilities: Letter of credit facilities n/a n/a n/a $ 249 n/a Letters of credit issued as of December 31, 2017 expire at various times in 2018 through 2020 . In June 2017, one of our committed letter of credit facilities with a borrowing capacity of $125 million expired and was not renewed. In November 2017, the remaining committed letter of credit facility with a borrowing capacity of $100 million was amended to extend the maturity date from November 2017 to November 2018 . We are charged letter of credit issuance fees under our various uncommitted short-term bank credit facilities. These uncommitted credit facilities have no commitment fees or compensating balance requirements. Non-Bank Debt There was no issuance or redemption activity related to our non-bank debt during the year ended December 31, 2017 . During the year ended December 31, 2016 , the following activity occurred: • We issued $1.25 billion of 3.4 percent Senior Notes due September 15, 2026 . Proceeds from this debt issuance totaled $1.246 billion . We also incurred $10 million of debt issuance costs. • We redeemed our 6.125 percent Senior Notes with a maturity date of June 15, 2017 for $778 million , or 103.70 percent of stated value. • We redeemed our 7.2 percent Senior Notes with a maturity date of October 15, 2017 for $213 million , or 106.27 percent of stated value. • VLP issued $500 million of 4.375 percent Senior Notes due December 15, 2026 . Proceeds from this debt issuance totaled $500 million . Debt issuance costs totaled $4 million . During the year ended December 31, 2015 , the following activity occurred: • We issued $600 million of 3.65 percent Senior Notes due March 15, 2025 and $650 million of 4.9 percent Senior Notes due March 15, 2045 . Proceeds from these debt issuances totaled $1.246 billion . We also incurred $12 million of debt issuance costs. • We made scheduled debt repayments of $400 million related to our 4.5 percent Senior Notes and $75 million related to our 8.75 percent debentures. Capital Lease Obligations We have capital lease obligations that mature at various dates through 2046 for storage tanks, terminal facilities, and other assets that are used in our refining operations. In January 2017, we recognized capital lease assets and related obligations totaling approximately $490 million for the lease of storage tanks located at three of our refineries. These lease agreements have initial terms of 10 years each with successive 10 -year automatic renewals. Other Disclosures Interest and debt expense, net of capitalized interest is comprised as follows (in millions): Year Ended December 31, 2017 2016 2015 Interest and debt expense $ 539 $ 511 $ 504 Less capitalized interest 71 65 71 Interest and debt expense, net of capitalized interest $ 468 $ 446 $ 433 Our credit facilities and other debt arrangements contain various customary restrictive covenants, including cross-default and cross-acceleration clauses. Principal maturities for our debt obligations and future minimum rentals on capital lease obligations as of December 31, 2017 were as follows (in millions): Debt Capital Lease Obligations 2018 $ 106 $ 55 2019 756 55 2020 1,266 53 2021 6 52 2022 6 54 Thereafter 6,243 969 Net unamortized debt issuance costs and other (73 ) n/a Total minimum lease payments n/a 1,238 Less amount representing interest n/a 676 Total $ 8,310 $ 562

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
COMMITMENTS AND CONTINGENCIES	9. COMMITMENTS AND CONTINGENCIES Operating Leases We have long-term operating lease commitments for land, office facilities and equipment, transportation equipment, time charters for ocean-going tankers and coastal vessels, dock facilities, and various facilities and equipment used in the storage, transportation, production, and sale of refinery feedstock, refined petroleum product and corn inventories. Certain leases for processing equipment and feedstock and refined petroleum product storage facilities provide for various contingent payments based on, among other things, throughput volumes in excess of a base amount. Certain leases for vessels contain renewal options and escalation clauses, which vary by charter, and provisions for the payment of chartering fees, which either vary based on usage or provide for payments, in addition to established minimums, that are contingent on usage. In most cases, we expect that in the normal course of business, our leases will be renewed or replaced by other leases. As of December 31, 2017 , our future minimum rentals for leases having initial or remaining noncancelable lease terms in excess of one year were as follows (in millions): 2018 $ 359 2019 236 2020 148 2021 104 2022 74 Thereafter 366 Total minimum rental payments $ 1,287 Minimum rentals to be received under subleases $ 15 “Rental expense, net of sublease rental income” was as follows (in millions): Year Ended December 31, 2017 2016 2015 Minimum rental expense $ 691 $ 739 $ 732 Contingent rental expense 21 70 105 Total rental expense 712 809 837 Less sublease rental income 54 31 46 Rental expense, net of sublease rental income $ 658 $ 778 $ 791 Purchase Obligations We have various purchase obligations under certain industrial gas and chemical supply arrangements (such as hydrogen supply arrangements), crude oil and other feedstock supply arrangements, and various throughput and terminaling agreements. We enter into these contracts to ensure an adequate supply of utilities and feedstock and adequate storage capacity to operate our refineries and ethanol plants. Substantially all of our purchase obligations are based on market prices or adjustments based on market indices. Certain of these purchase obligations include fixed or minimum volume requirements, while others are based on our usage requirements. None of these obligations are associated with suppliers’ financing arrangements. These purchase obligations are not reflected as liabilities. Other Commitments MVP Terminal We have a 50 percent membership interest in MVP Terminalling, LLC (MVP), a Delaware limited liability company formed in September 2017 with a subsidiary of Magellan Midstream Partners LP (Magellan), to construct, own, and operate the Magellan Valero Pasadena marine terminal (MVP Terminal) located adjacent to the Houston Ship Channel in Pasadena, Texas. The MVP Terminal will contain (i) approximately 5 million barrels of storage capacity, (ii) a dock with two ship berths, and (iii) a three-bay truck rack facility. In connection with our terminaling agreement with MVP, described below, we will have dedicated use of (i) approximately 4 million barrels of storage, (ii) one ship berth, and (iii) the three-bay truck rack facility. Construction of phases one and two of the project began in 2017 with a total estimated cost of $840 million , of which we have committed to contribute 50 percent (approximately $420 million ). The project could expand up to four phases with a total project cost of approximately $1.4 billion if warranted by additional demand and agreed to by Magellan and us. We have contributed $81 million to MVP through December 2017 . Concurrent with the formation of MVP, we entered into a terminaling agreement with MVP to utilize the MVP Terminal upon completion of phase two, which is expected to occur in early 2020. The terminaling agreement has an initial term of 12 years with two five -year automatic renewals, and year-to-year renewals thereafter. Due to our membership interest in MVP and because the terminaling agreement was determined to be a capital lease, we are the accounting owner of the MVP Terminal during the construction period. Accordingly, as of December 31, 2017 , we recorded an asset of $174 million in property, plant, and equipment representing 100 percent of the construction costs incurred by MVP, as well as capitalized interest incurred by us, and a long-term liability of $94 million payable to Magellan. The amounts recorded for the portion of the construction costs associated with the payable to Magellan are noncash investing and financing items, respectively. Central Texas Pipeline and Terminal Projects We have committed to a 40 percent undivided interest in a project with a subsidiary of Magellan to jointly build an estimated 135 -mile, 20 -inch refined petroleum products pipeline with a capacity of up to 150,000 barrels per day from Houston to Hearne, Texas. The pipeline is expected to be completed in mid-2019. Our estimated cost to acquire our 40 percent undivided interest in this pipeline is $170 million . We have incurred capital expenditures of $7 million through December 2017 . Sunrise Pipeline System Effective January 31, 2018, we entered into a joint ownership agreement with Sunrise Pipeline LLC, a subsidiary of Plains All American Pipeline, L.P. (Plains) to acquire a 20 percent undivided interest in the expanded Sunrise Pipeline System to be constructed by Plains. The Sunrise Pipeline System will contain (i) a 262 -mile, 24 -inch crude oil pipeline (the Sunrise Pipeline) that will originate at Plains’ terminal in Midland, Texas and will end at Plains’ station in Wichita Falls, Texas with throughput capacity of 500,000 barrels per day, and (ii) two 270,000 shell barrel capacity tanks located at the Colorado City, Texas station (the Colorado City Storage Tanks). The Sunrise Pipeline System expansion is expected to begin construction in early 2018 and continue through the first half of 2019. The cost to acquire our 20 percent undivided interest in the Sunrise Pipeline System is $135 million , of which $34 million was paid on February 1, 2018. Including the February 2018 payment, we expect to incur approximately $101 million during 2018. Environmental Matters We are involved, together with several other companies, in an environmental cleanup in the Village of Hartford, Illinois (the Village) and during 2015, one of these companies assumed the ongoing remediation in the Village pursuant to a federal court order. We had previously conducted an initial response in the Village, along with other companies, pursuant to an administrative order issued by the U.S. EPA. The parties involved in the initial response may have further claims among themselves for costs already incurred. We also continue to be engaged in site assessment and interim measures at the adjacent shutdown refinery site, which we acquired as part of an acquisition in 2005, and we are in litigation with other potentially responsible parties and the Illinois EPA relating to the remediation of the site. In each of these matters, we have various defenses, limitations, and potential rights for contribution from the other responsible parties. We have recorded a liability for our expected contribution obligations. However, because of the unpredictable nature of these cleanups, the methodology for allocation of liabilities, and the State of Illinois’ failure to directly sue third parties responsible for historic contamination at the site, it is reasonably possible that we could incur a loss in a range of $0 to $200 million in excess of the amount of our accrual to ultimately resolve these matters. Factors underlying this estimated range are expected to change from time to time, and actual results may vary significantly from this estimate. Litigation Matters We are party to claims and legal proceedings arising in the ordinary course of business. We have not recorded a loss contingency liability with respect to some of these matters because we have determined that it is remote that a loss has been incurred. For other matters, we have recorded a loss contingency liability where we have determined that it is probable that a loss has been incurred and that the loss is reasonably estimable. These loss contingency liabilities are not material to our financial position. We re-evaluate and update our loss contingency liabilities as matters progress over time, and we believe that any changes to the recorded liabilities will not be material to our financial position, results of operations, or liquidity. Self-Insurance We are self-insured for certain medical and dental, workers’ compensation, automobile liability, general liability, and property liability claims up to applicable retention limits. Liabilities are accrued for self-insured claims, or when estimated losses exceed coverage limits, and when sufficient information is available to reasonably estimate the amount of the loss. These liabilities are included in accrued expenses and other long-term liabilities.

Equity

Equity	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
EQUITY	10. EQUITY Share Activity Activity in the number of shares of common stock and treasury stock was as follows (in millions): Common Stock Treasury Stock Balance as of December 31, 2014 673 (159 ) Transactions in connection with stock-based compensation plans — 1 Stock purchases under purchase program — (42 ) Balance as of December 31, 2015 673 (200 ) Transactions in connection with stock-based compensation plans — 1 Stock purchases under purchase program — (23 ) Balance as of December 31, 2016 673 (222 ) Transactions in connection with stock-based compensation plans — 1 Stock purchases under purchase program — (19 ) Balance as of December 31, 2017 673 (240 ) Preferred Stock We have 20 million shares of preferred stock authorized with a par value of $0.01 per share. No shares of preferred stock were outstanding as of December 31, 2017 or 2016 . Treasury Stock We purchase shares of our common stock as authorized under our common stock purchase program (described below) and to meet our obligations under employee stock-based compensation plans. On February 28, 2008 , our board of directors approved a $3 billion common stock purchase program with no expiration date, and we completed that program during 2015. On July 13, 2015 , our board of directors authorized us to purchase an additional $2.5 billion of our outstanding common stock (the 2015 program) with no expiration date, and we completed that program during 2017. On September 21, 2016, our board of directors authorized our purchase of up to an additional $2.5 billion (the 2016 program) with no expiration date. During the years ended December 31, 2017 , 2016 , and 2015 , we purchased $1.3 billion , $1.3 billion , and $2.7 billion , respectively, of our common stock under our programs. As of December 31, 2017 , we have approvals under the 2016 program to purchase approximately $1.2 billion of our common stock. On January 23, 2018, our board of directors authorized our purchase of up to an additional $2.5 billion of our outstanding common stock with no expiration date. Common Stock Dividends On January 23, 2018 , our board of directors declared a quarterly cash dividend of $0.80 per common share payable on March 6, 2018 to holders of record at the close of business on February 13, 2018 . Valero Energy Partners LP Units On September 16, 2016, VLP entered into an equity distribution agreement pursuant to which VLP may offer and sell from time to time their common units having an aggregate offering price of up to $350 million based on 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, referred to as the “ATM Program”). VLP issued 742,897 and 223,083 common units under the ATM Program and received net proceeds of $35 million and $9 million after deducting offering costs during the years ended December 31, 2017 and 2016 , respectively. Effective November 24, 2015, VLP completed a public offering of 4,250,000 common units at a price of $46.25 per unit and received net proceeds from the offering of $189 million after deducting the underwriting discount and other offering costs. Income Tax Effects Related to Components of Other Comprehensive Income (Loss) The tax effects allocated to each component of other comprehensive income (loss) were as follows (in millions): Before-Tax Amount Tax Expense (Benefit) Net Amount Year Ended December 31, 2017: Foreign currency translation adjustment $ 514 $ — $ 514 Pension and other postretirement benefits: Loss arising during the year related to: Net actuarial loss (79 ) (29 ) (50 ) Prior service cost (4 ) (1 ) (3 ) Miscellaneous loss — 3 (3 ) Amounts reclassified into income related to: Net actuarial loss 50 18 32 Prior service credit (36 ) (13 ) (23 ) Curtailment and settlement loss 4 1 3 Net loss on pension and other postretirement benefits (65 ) (21 ) (44 ) Other comprehensive income $ 449 $ (21 ) $ 470 Before-Tax Amount Tax Expense (Benefit) Net Amount Year Ended December 31, 2016: Foreign currency translation adjustment $ (415 ) $ — $ (415 ) Pension and other postretirement benefits: Gain (loss) arising during the year related to: Net actuarial loss (110 ) (34 ) (76 ) Miscellaneous gain — (8 ) 8 Amounts reclassified into income related to: Net actuarial loss 48 18 30 Prior service credit (36 ) (13 ) (23 ) Net loss on pension and other postretirement benefits (98 ) (37 ) (61 ) Other comprehensive loss $ (513 ) $ (37 ) $ (476 ) Year Ended December 31, 2015: Foreign currency translation adjustment $ (606 ) $ — $ (606 ) Pension and other postretirement benefits: Gain (loss) arising during the year related to: Net actuarial gain 50 15 35 Prior service cost (22 ) (8 ) (14 ) Amounts reclassified into income related to: Net actuarial loss 62 22 40 Prior service credit (40 ) (14 ) (26 ) Curtailment and settlement loss 7 2 5 Net gain on pension and other postretirement benefits 57 17 40 Other comprehensive loss $ (549 ) $ 17 $ (566 ) Accumulated Other Comprehensive Income (Loss) Changes in accumulated other comprehensive income (loss) by component, net of tax, were as follows (in millions): Foreign Currency Translation Adjustment Defined Benefit Plan Items Total Balance as of December 31, 2014 $ 1 $ (368 ) $ (367 ) Other comprehensive income (loss) before reclassifications (606 ) 21 (585 ) Amounts reclassified from accumulated other comprehensive income (loss) — 19 19 Net other comprehensive income (loss) (606 ) 40 (566 ) Balance as of December 31, 2015 (605 ) (328 ) (933 ) Other comprehensive loss before reclassifications (416 ) (68 ) (484 ) Amounts reclassified from accumulated other comprehensive loss — 7 7 Net other comprehensive loss (416 ) (61 ) (477 ) Balance as of December 31, 2016 (1,021 ) (389 ) (1,410 ) Other comprehensive income (loss) before reclassifications 514 (56 ) 458 Amounts reclassified from accumulated other comprehensive loss — 12 12 Net other comprehensive income (loss) 514 (44 ) 470 Balance as of December 31, 2017 $ (507 ) $ (433 ) $ (940 ) Gains (losses) reclassified out of accumulated other comprehensive loss and into net income were as follows (in millions): Details about Accumulated Other Comprehensive Loss Components Affected Line Item in the Statement of Income Year Ended December 31, 2017 2016 2015 Amortization of items related to defined benefit pension plans: Net actuarial loss $ (50 ) $ (48 ) $ (62 ) (a) Prior service credit 36 36 40 (a) Curtailment and settlement (4 ) — (7 ) (a) (18 ) (12 ) (29 ) Total before tax 6 5 10 Tax benefit Total reclassifications for the year $ (12 ) $ (7 ) $ (19 ) Net of tax _________________________ (a) These accumulated other comprehensive loss components are included in the computation of net periodic benefit cost, as further discussed in Note 12 . Net periodic benefit cost is reflected in operating expenses (excluding depreciation and amortization expense) and general and administrative expenses (excluding depreciation and amortization expense).

Variable Interest Entities

Variable Interest Entities	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
VARIABLE INTEREST ENTITIES	11. VARIABLE INTEREST ENTITIES Consolidated VIEs In the normal course of business, we have financial interests in certain entities that have been determined to be VIEs. We consolidate a VIE when we have a variable interest in an entity for which we are the primary beneficiary such that we have (a) the power to direct the activities of the VIE that most significantly impact the VIE’s economic performance and (b) the obligation to absorb losses of or the right to receive benefits from the VIE that could potentially be significant to the VIE. In order to make this determination, we evaluated our contractual arrangements with the VIEs, including arrangements for the use of assets, purchases of products and services, debt, equity, or management of operating activities. The following discussion summarizes our involvement with our VIEs: • VLP is a publicly traded master limited partnership whose common limited partner units are traded on the New York Stock Exchange under “VLP.” We formed VLP in July 2013 to own, operate, develop, and acquire crude oil and refined petroleum products pipelines, terminals, and other transportation and logistics assets. VLP’s assets include crude oil and refined petroleum products pipeline and terminal systems in the U.S. Gulf Coast and U.S. Mid-Continent regions that are integral to the operations of ten of our refineries. As of December 31, 2017 , we owned a 66.2 percent limited partner interest and a 2.0 percent general partner interest in VLP, and public unitholders owned a 31.8 percent limited partner interest. We determined VLP is a VIE because the public limited partners of VLP ( i.e. , parties other than entities under common control with the general partner) lack the power to direct the activities of VLP that most significantly impact its economic performance because they do not have substantive kick-out rights over the general partner or substantive participating rights in VLP. Furthermore, we determined that we are the primary beneficiary of VLP because (a) we are the single decision maker and because our general partner interest provides us with the sole power to direct the activities that most significantly impact VLP’s economic performance and (b) our 66.2 percent limited partner interest and 2.0 percent general partner interest provide us with significant economic rights and obligations. Substantially all of VLP’s revenues are derived from us; therefore, there is limited risk to us associated with VLP’s operations. • Diamond Green Diesel Holdings LLC (DGD) is a joint venture with Darling Green Energy LLC, a subsidiary of Darling Ingredients Inc., that was formed to construct and operate a biodiesel plant that processes animal fats, used cooking oils, and other vegetable oils into renewable green diesel. The plant is located next to our St. Charles Refinery and began operations in June 2013. Our significant agreements with DGD include an operations agreement that outlines our responsibilities as operator of the plant, a debt agreement whereby we financed approximately 60 percent of the construction costs of the plant, and a marketing agreement. As operator, we operate the plant and perform certain day-to-day operating and management functions for DGD as an independent contractor. The operations agreement provides us (as operator) and, in the event of certain conditions, the debt agreement provides us (as lender) with certain power to direct the activities that most significantly impact DGD’s economic performance. Because the operations agreement and the debt agreement convey such power to us and are separate from our ownership rights, DGD was determined to be a VIE. For this reason and because we hold a 50 percent ownership interest that provides us with significant economic rights and obligations, we determined that we are the primary beneficiary of DGD. DGD has risk associated with its operations because it generates revenues from third-party customers. • We have terminaling agreements with three subsidiaries of Infraestructura Energetica Nova, S.A.B. de C.V. (IEnova), a Mexican subsidiary of Sempra Energy, a U.S. public company (the three subsidiaries are collectively referred to as VPM Terminals). The terminaling agreements represent variable interests because we have determined them to be capital leases due to our exclusive use of the terminals. Although we do not have an ownership interest in the entities that own each of the three terminals, the capital leases convey to us (i) the power to direct the activities that most significantly impact the economic performance of all three terminals and (ii) the ability to influence the benefits received or the losses incurred by the terminals because of our use of the terminals. As a result, we determined each of the entities was a VIE and that we are the primary beneficiary of each. Substantially all of VPM Terminals’ revenues will be derived from us; therefore, there is limited risk to us associated with VPM Terminals’ operations. • We also have financial interests in other entities that have been determined to be VIEs because the entities’ contractual arrangements transfer the power to direct the activities that most significantly impact their economic performance or reduce the exposure to operational variability and risk of loss created by the entity that otherwise would be held exclusively by the equity owners. Furthermore, we determined that we are the primary beneficiary of these VIEs because (a) certain contractual arrangements (exclusive of our ownership rights) provide us with the power to direct the activities that most significantly impact the economic performance of these entities and/or (b) our 50 percent ownership interests provide us with significant economic rights and obligations. The financial position, results of operations, and cash flows of these VIEs are not material to us. The VIEs’ assets can only be used to settle their own obligations and the VIEs’ creditors have no recourse to our assets. We do not provide financial guarantees to our VIEs. Although we have provided credit facilities to some of our VIEs in support of their construction or acquisition activities, these transactions are eliminated in consolidation. Our financial position, results of operations, and cash flows are impacted by our consolidated VIEs’ performance, net of intercompany eliminations, to the extent of our ownership interest in each VIE. The following tables present summarized balance sheet information for the significant assets and liabilities of our VIEs, which are included in our balance sheets (in millions). December 31, 2017 VLP DGD VPM Terminals Other Total Assets Cash and temporary cash investments $ 42 $ 123 $ 1 $ 13 $ 179 Other current assets 2 66 4 — 72 Property, plant, and equipment, net 1,416 435 51 127 2,029 Liabilities Current liabilities $ 27 $ 33 $ 26 $ 9 $ 95 Debt and capital lease obligations, less current portion 905 — — 43 948 December 31, 2016 VLP DGD Other Total Assets Cash and temporary cash investments $ 71 $ 167 $ 15 $ 253 Other current assets 3 87 — 90 Property, plant, and equipment, net 865 355 133 1,353 Liabilities Current liabilities $ 15 $ 17 $ 7 $ 39 Debt and capital lease obligations, less current portion 525 — 46 571 Non-Consolidated VIEs We hold variable interests in VIEs that have not been consolidated because we are not considered the primary beneficiary. These non-consolidated VIEs are not material to our financial position or results of operations and are primarily accounted for as equity investments. However, one of our non-consolidated VIEs is accounted for under owner accounting and is further described below and in Note 9 . As described in Note 9 , we have a 50 percent membership interest in MVP, which was formed to construct, own, and operate the MVP Terminal. We determined MVP is a VIE because the power to direct the activities that most significantly impact its economic performance is not required to be held by its two members, but is held by Magellan, as operator under a construction, operating, and management agreement with MVP. For this reason and because Magellan holds a 50 percent interest in MVP that provides it with significant economic rights and obligations, we determined that we are not the primary beneficiary. As of December 31, 2017 , our maximum exposure to loss was $80 million , which represents our equity investment in MVP.

Employee Benefit Plans

Employee Benefit Plans	12 Months Ended
	Dec. 31, 2017
Retirement Benefits [Abstract]
EMPLOYEE BENEFIT PLANS	12. EMPLOYEE BENEFIT PLANS Defined Benefit Plans We have defined benefit pension plans, some of which are subject to collective bargaining agreements, that cover most of our employees. These plans provide eligible employees with retirement income based primarily on years of service and compensation during specific periods under final average pay and cash balance formulas. We fund our pension plans as required by local regulations. In the U.S., all qualified pension plans are subject to the Employee Retirement Income Security Act minimum funding standard. We typically do not fund or fully fund U.S. nonqualified and certain international pension plans that are not subject to funding requirements because contributions to these pension plans may be less economic and investment returns may be less attractive than our other investment alternatives. We also provide health care and life insurance benefits for certain retired employees through our postretirement benefit plans. Most of our employees become eligible for these benefits if, while still working for us, they reach normal retirement age or take early retirement. These plans are unfunded, and retired employees share the cost with us. Individuals who became our employees as a result of an acquisition became eligible for other postretirement benefits under our plans as determined by the terms of the relevant acquisition agreement. The changes in benefit obligation related to all of our defined benefit plans, the changes in fair value of plan assets (a) , and the funded status of our defined benefit plans as of and for the years ended were as follows (in millions): Pension Plans Other Postretirement Benefit Plans December 31, December 31, 2017 2016 2017 2016 Changes in benefit obligation: Benefit obligation as of beginning of year $ 2,567 $ 2,365 $ 302 $ 336 Service cost 123 111 6 7 Interest cost 86 84 10 12 Participant contributions — — 9 8 Benefits paid (158 ) (130 ) (28 ) (27 ) Actuarial (gain) loss 286 171 6 (35 ) Other 22 (34 ) 1 1 Benefit obligation as of end of year $ 2,926 $ 2,567 $ 306 $ 302 Changes in plan assets (a): Fair value of plan assets as of beginning of year $ 2,097 $ 1,947 $ — $ — Actual return on plan assets 363 165 — — Valero contributions 110 141 19 18 Participant contributions — — 9 8 Benefits paid (158 ) (130 ) (28 ) (27 ) Other 16 (26 ) — 1 Fair value of plan assets as of end of year $ 2,428 $ 2,097 $ — $ — Reconciliation of funded status (a) : Fair value of plan assets as of end of year $ 2,428 $ 2,097 $ — $ — Less benefit obligation as of end of year 2,926 2,567 306 302 Funded status as of end of year $ (498 ) $ (470 ) $ (306 ) $ (302 ) Accumulated benefit obligation $ 2,746 $ 2,419 n/a n/a ___________________________ (a) Plan assets include only the assets associated with pension plans subject to legal minimum funding standards. Plan assets associated with U.S. nonqualified pension plans are not included here because they are not protected from our creditors and therefore cannot be reflected as a reduction from our obligations under the pension plans. As a result, the reconciliation of funded status does not reflect the effect of plan assets that exist for all of our defined benefit plans. See Note 18 for the assets associated with certain U.S. nonqualified pension plans. Amounts recognized in our balance sheet for our pension and other postretirement benefits plans include (in millions): Pension Plans Other Postretirement Benefit Plans December 31, December 31, 2017 2016 2017 2016 Deferred charges and other assets, net $ 5 $ 2 $ — $ — Accrued expenses (14 ) (13 ) (19 ) (19 ) Other long-term liabilities (489 ) (459 ) (287 ) (283 ) $ (498 ) $ (470 ) $ (306 ) $ (302 ) The accumulated benefit obligations for certain of our pension plans exceed the fair values of the assets of those plans. For those plans, the following table presents the total projected benefit obligation, accumulated benefit obligation, and fair value of the plan assets (in millions). December 31, 2017 2016 Projected benefit obligation $ 2,661 $ 2,322 Accumulated benefit obligation 2,526 2,210 Fair value of plan assets 2,180 1,870 Benefit payments that we expect to pay, including amounts related to expected future services that we expect to receive, are as follows for the years ending December 31 (in millions): Pension Benefits Other Postretirement Benefits 2018 $ 162 $ 19 2019 219 19 2020 184 19 2021 180 19 2022 185 19 2023-2027 1,074 93 We plan to contribute approximately $131 million to our pension plans, including discretionary contributions of $100 million , and $19 million to our other postretirement benefit plans during 2018 . The components of net periodic benefit cost (credit) related to our defined benefit plans were as follows (in millions): Pension Plans Other Postretirement Benefit Plans Year Ended December 31, Year Ended December 31, 2017 2016 2015 2017 2016 2015 Service cost $ 123 $ 111 $ 109 $ 6 $ 7 $ 8 Interest cost 86 84 98 10 12 14 Expected return on plan assets (150 ) (139 ) (133 ) — — — Amortization of: Net actuarial (gain) loss 53 49 62 (3 ) (1 ) — Prior service credit (20 ) (20 ) (22 ) (16 ) (16 ) (18 ) Special charges (credits) 4 (7 ) 7 — — — Net periodic benefit cost (credit) $ 96 $ 78 $ 121 $ (3 ) $ 2 $ 4 Amortization of prior service credit shown in the preceding table was based on a straight-line amortization of the cost over the average remaining service period of employees expected to receive benefits under each respective plan. Amortization of the net actuarial (gain) loss shown in the preceding table was based on the straight-line amortization of the excess of the unrecognized (gain) loss over 10 percent of the greater of the projected benefit obligation or market-related value of plan assets (smoothed asset value) over the average remaining service period of active employees expected to receive benefits under each respective plan. Pre-tax amounts recognized in other comprehensive income (loss) were as follows (in millions): Pension Plans Other Postretirement Benefit Plans Year Ended December 31, Year Ended December 31, 2017 2016 2015 2017 2016 2015 Net gain (loss) arising during the year: Net actuarial gain (loss) $ (73 ) $ (145 ) $ 24 $ (6 ) $ 35 $ 26 Prior service cost (4 ) — (22 ) — — — Net (gain) loss reclassified into income: Net actuarial (gain) loss 53 49 62 (3 ) (1 ) — Prior service credit (20 ) (20 ) (22 ) (16 ) (16 ) (18 ) Curtailment and settlement loss 4 — 7 — — — Total changes in other comprehensive income (loss) $ (40 ) $ (116 ) $ 49 $ (25 ) $ 18 $ 8 The pre-tax amounts in accumulated other comprehensive loss that have not yet been recognized as components of net periodic benefit cost (credit) were as follows (in millions): Pension Plans Other Postretirement Benefit Plans December 31, December 31, 2017 2016 2017 2016 Net actuarial (gain) loss $ 894 $ 878 $ (57 ) $ (66 ) Prior service credit (121 ) (145 ) (42 ) (58 ) Total $ 773 $ 733 $ (99 ) $ (124 ) The following pre-tax amounts included in accumulated other comprehensive loss as of December 31, 2017 are expected to be recognized as components of net periodic benefit cost (credit) during the year ending December 31, 2018 (in millions): Pension Plans Other Postretirement Benefit Plans Amortization of net actuarial (gain) loss $ 66 $ (2 ) Amortization of prior service credit (19 ) (11 ) Total $ 47 $ (13 ) The weighted-average assumptions used to determine the benefit obligations were as follows: Pension Plans Other Postretirement Benefit Plans December 31, December 31, 2017 2016 2017 2016 Discount rate 3.58 % 4.08 % 3.72 % 4.26 % Rate of compensation increase 3.86 % 3.81 % n/a n/a The discount rate assumption used to determine the benefit obligations as of December 31, 2017 and 2016 for the majority of our pension plans and other postretirement benefit plans was based on the Aon Hewitt AA Only Above Median yield curve and considered the timing of the projected cash outflows under our plans. This curve was designed by Aon Hewitt to provide a means for plan sponsors to value the liabilities of their pension plans or postretirement benefit plans. It is a hypothetical double-A yield curve represented by a series of annualized individual discount rates with maturities from one-half year to 99 years . Each bond issue underlying the curve is required to have an average rating of double-A when averaging all available ratings by Moody’s Investor Services, Standard and Poor’s Ratings Service, and Fitch Ratings. Only the bonds representing the 50 percent highest yielding issuances among those with average ratings of double-A are included in this yield curve. We based our discount rate assumption on the Aon Hewitt AA Only Above Median yield curve because we believe it is representative of the types of bonds we would use to settle our pension and other postretirement benefit plan liabilities as of those dates. We believe that the yields associated with the bonds used to develop this yield curve reflect the current level of interest rates. The weighted-average assumptions used to determine the net periodic benefit cost were as follows: Pension Plans Other Postretirement Benefit Plans Year Ended December 31, Year Ended December 31, 2017 2016 2015 2017 2016 2015 Discount rate 4.08 % 4.45 % 4.10 % 4.26 % 4.53 % 4.13 % Expected long-term rate of return on plan assets 7.29 % 7.28 % 7.29 % n/a n/a n/a Rate of compensation increase 3.81 % 3.79 % 3.78 % n/a n/a n/a The assumed health care cost trend rates were as follows: December 31, 2017 2016 Health care cost trend rate assumed for the next year 7.30 % 7.28 % Rate to which the cost trend rate was assumed to decline (the ultimate trend rate) 5.00 % 5.00 % Year that the rate reaches the ultimate trend rate 2026 2026 Assumed health care cost trend rates impact the amounts reported for retiree health care plans. A one percentage-point increase or decrease in assumed health care cost trend rates would have an immaterial effect on the total of service and interest cost components and on the accumulated postretirement benefit obligation on our postretirement benefits. The following tables present the fair values of the assets of our pension plans (in millions) as of December 31, 2017 and 2016 by level of the fair value hierarchy. Assets categorized in Level 1 of the hierarchy are measured at fair value using a market approach based on quotations from national securities exchanges. Assets categorized in Level 2 of the hierarchy are measured at net asset value in a market that is not active. As previously noted, we do not fund or fully fund U.S. nonqualified and certain international pension plans that are not subject to funding requirements, and we do not fund our other postretirement benefit plans. Fair Value Measurements Using Total as of Level 1 Level 2 Level 3 Equity securities: U.S. companies (a) $ 571 $ — $ — $ 571 International companies 187 1 — 188 Preferred stock 4 — — 4 Mutual funds: International growth 118 — — 118 Index funds (b) 85 — — 85 Corporate debt instruments — 272 — 272 Government securities: U.S. Treasury securities 45 — — 45 Other government securities — 144 — 144 Common collective trusts (c) — 621 — 621 Pooled separate accounts — 192 — 192 Private funds — 101 — 101 Insurance contract — 18 — 18 Interest and dividends receivable 5 — — 5 Cash and cash equivalents 85 1 — 86 Securities transactions payable, net (22 ) — — (22 ) Total pension assets $ 1,078 $ 1,350 $ — $ 2,428 ___________________________ See notes on page 109 . Fair Value Measurements Using Total as of Level 1 Level 2 Level 3 Equity securities: U.S. companies (a) $ 562 $ — $ — $ 562 International companies 164 — — 164 Preferred stock 3 — — 3 Mutual funds: International growth 90 — — 90 Index funds (b) 230 — — 230 Corporate debt instruments — 280 — 280 Government securities: U.S. Treasury securities 52 — — 52 Other government securities — 158 — 158 Common collective trusts (c) — 434 — 434 Private funds — 76 — 76 Insurance contract — 18 — 18 Interest and dividends receivable 5 — — 5 Cash and cash equivalents 56 16 — 72 Securities transactions payable, net (47 ) — — (47 ) Total pension assets $ 1,115 $ 982 $ — $ 2,097 __________________________________ (a) Equity securities are held in a wide range of industrial sectors, including consumer goods, information technology, healthcare, industrials, and financial services. (b) This class includes primarily investments in approximately 70 percent equities and 30 percent bonds as of December 31, 2017 . As of December 31, 2016 , the class included primarily investments in approximately 50 percent equities and 50 percent bonds. (c) This class includes primarily investments in approximately 80 percent equities and 20 percent bonds as of December 31, 2017 . As of December 31, 2016 , the class included primarily investments in approximately 90 percent equities and 10 percent bonds. The investment policies and strategies for the assets of our pension plans incorporate a well-diversified approach that is expected to earn long-term returns from capital appreciation and a growing stream of current income. This approach recognizes that assets are exposed to risk and the market value of the pension plans’ assets may fluctuate from year to year. Risk tolerance is determined based on our financial ability to withstand risk within the investment program and the willingness to accept return volatility. In line with the investment return objective and risk parameters, the pension plans’ mix of assets includes a diversified portfolio of equity and fixed-income investments. Equity securities include international stocks and a blend of U.S. growth and value stocks of various sizes of capitalization. Fixed income securities include bonds and notes issued by the U.S. government and its agencies, corporate bonds, and mortgage-backed securities. The aggregate asset allocation is reviewed on an annual basis. As of December 31, 2017 , the target allocations for plan assets under our primary pension plan are 70 percent equity securities and 30 percent fixed income investments. The expected long-term rate of return on plan assets is based on a forward-looking expected asset return model. This model derives an expected rate of return based on the target asset allocation of a plan’s assets. The underlying assumptions regarding expected rates of return for each asset class reflect Aon Hewitt’s best expectations for these asset classes. The model reflects the positive effect of periodic rebalancing among diversified asset classes. We select an expected asset return that is supported by this model. Defined Contribution Plans We have defined contribution plans that cover most of our employees. Our contributions to these plans are based on employees’ compensation and/or a partial match of employee contributions to the plans. Our contributions to these defined contribution plans were $70 million , $67 million , and $65 million for the years ended December 31, 2017 , 2016 , and 2015 , respectively.

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
STOCK-BASED COMPENSATION	13. STOCK-BASED COMPENSATION Overview Under our 2011 Omnibus Stock Incentive Plan (the OSIP), various stock and stock-based awards may be granted to employees and non-employee directors. Awards available under the OSIP include options to purchase shares of common stock, performance awards that vest upon the achievement of an objective performance goal, stock appreciation rights, restricted stock that vests over a period determined by our compensation committee, and dividend equivalent rights (DERs). The OSIP was approved by our stockholders on April 28, 2011 and re-approved by our stockholders on May 12, 2016. As of December 31, 2017 , 9,409,188 shares of our common stock remained available to be awarded under the OSIP. We also maintain other stock-based compensation plans under which previously granted equity awards remain outstanding. No additional grants may be awarded under these plans. The following table reflects activity related to our stock-based compensation arrangements (in millions): Year Ended December 31, 2017 2016 2015 Stock-based compensation expense: Restricted stock $ 58 $ 52 $ 47 Performance awards 19 15 11 Stock options — 1 1 Total stock-based compensation expense $ 77 $ 68 $ 59 Tax benefit recognized on stock-based compensation expense $ 27 $ 24 $ 21 Tax benefit realized for tax deductions resulting from exercises and vestings 44 33 66 Effect of tax deductions in excess of recognized stock-based compensation expense (a) 24 22 44 _______________________________ (a) Effective January 1, 2016, the effect of tax deductions in excess of recognized stock-based compensation expense is reported as an operating cash flow. These amounts were previously reported as financing cash flows. Our significant stock-based compensation arrangement is discussed below. Restricted Stock Restricted stock is granted to employees and non-employee directors. Restricted stock granted to employees vests in accordance with individual written agreements between the participants and us, usually in equal annual installments over a period of three years beginning one year after the date of grant. Restricted stock granted to our non-employee directors vests in equal annual installments over a period of three years beginning one year after the date of grant. The fair value of each restricted stock per share is equal to the market price of our common stock. A summary of the status of our restricted stock awards is presented in the following table. Number of Shares Weighted- Average Grant-Date Fair Value Per Share Nonvested shares as of January 1, 2017 1,566,950 $ 60.68 Granted 739,393 79.32 Vested (897,246 ) 61.76 Forfeited (8,057 ) 61.22 Nonvested shares as of December 31, 2017 1,401,040 69.82 As of December 31, 2017 , there was $61 million of unrecognized compensation cost related to outstanding unvested restricted stock awards, which is expected to be recognized over a weighted-average period of approximately two years. The following table reflects activity related to our restricted stock (in millions, except per share data): Year Ended December 31, 2017 2016 2015 Weighted-average grant-date fair value per share of restricted stock granted $ 79.32 $ 59.00 $ 70.07 Fair value of restricted stock vested 71 46 69

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
INCOME TAXES	14. INCOME TAXES Tax Reform On December 22, 2017, Tax Reform was enacted, which resulted in significant changes to the U.S. Internal Revenue Code of 1986, as amended (the Code) and was effective beginning on January 1, 2018. The most significant changes affecting us are as follows: • reduction in the statutory income tax rate from 35 percent to 21 percent; • repeal of the manufacturing deduction; • deduction for all of the costs to acquire or construct certain business assets in the year they are placed in service through 2022; • shift from a worldwide system of taxation to a territorial system of taxation, resulting in a minimum tax on the income of international subsidiaries (the global intangible low-taxes income (GILTI) tax) rather than a tax deferral on such earnings in certain circumstances; and • assessment of a one-time transition tax on deemed repatriated earnings and profits from our international subsidiaries. We reflected an overall income tax benefit of $1.9 billion for the year ended December 31, 2017 with respect to Tax Reform as a result of the following: • We remeasured our U.S. deferred tax assets and liabilities using the 21 percent rate, which resulted in a tax benefit and a reduction to our net deferred tax liabilities of $2.6 billion . • We recognized a one-time transition tax of $734 million on the deemed repatriation of previously undistributed accumulated earnings and profits of our international subsidiaries based on approximately $4.7 billion of the combined earnings and profits of our international subsidiaries that have not been distributed to us. This transition tax will be remitted to the Internal Revenue Service (IRS) over the eight-year period provided in the Code beginning in 2018. • We accrued withholding tax of $47 million on a portion of the cash held by one of our international subsidiaries that we have deemed to not be permanently reinvested in our operations in that country. Because of the significant and complex changes to the Code from Tax Reform, including the need for regulatory guidance from the IRS to properly account for many of the provisions, the SEC issued Staff Accounting Bulletin No. 118, “Income Tax Accounting Implications of the Tax Cuts and Jobs Act,” (SAB 118) to provide for a measurement period of up to one year for adjustments to be made to account for the effects of Tax Reform. Specifically, SAB 118 requires that the effects of Tax Reform be recorded for items where the accounting is complete, as well as for items where a reasonable estimate can be made (referred to as provisional amounts). For items where reasonable estimates cannot be made, provisional amounts should not be recorded and those items should continue to be accounted for under the Code prior to changes from Tax Reform until a reasonable estimate can be made. See “Details of the Tax Reform Adjustment” below, which more fully describes the components of our $1.9 billion adjustment, including the components for which we recorded a provisional amount and the components that are incomplete. Income Statement Components Income before income tax expense (benefit) was as follows (in millions): Year Ended December 31, 2017 2016 2015 U.S. operations $ 2,283 $ 1,733 $ 5,327 International operations 924 1,449 644 Income before income tax expense (benefit) $ 3,207 $ 3,182 $ 5,971 Statutory income tax rates applicable to the countries in which we operate were as follows: Year Ended December 31, 2017 2016 2015 U.S. (a) 35 % 35 % 35 % Canada 15 % 15 % 15 % U.K. 19 % 20 % 20 % Ireland 13 % 13 % 13 % Aruba (b) n/a 7 % 7 % ___________________________ (a) Statutory income tax rate was reduced to 21 percent effective January 1, 2018 as described in “Tax Reform” above. (b) Statutory income tax rate applicable through the date of the Aruba Disposition as described in Note 2 . The following is a reconciliation of income tax expense (benefit) computed by applying statutory income tax rates as reflected in the preceding table to actual income tax expense (benefit) related to our operations (in millions): Year Ended December 31, 2017 U.S. International Total Amount Percent Amount Percent Amount Percent Income tax expense at statutory rates $ 799 35.0 % $ 158 17.1 % $ 957 29.8 % U.S. state and Canadian provincial tax expense, net of federal income tax effect 37 1.6 % 46 5.0 % 83 2.6 % Permanent differences: Manufacturing deduction (42 ) (1.8 )% — — (42 ) (1.3 )% Other (9 ) (0.4 )% — — (9 ) (0.3 )% Change in tax law (1,862 ) (81.6 )% — — (1,862 ) (58.1 )% Tax effects of income associated with noncontrolling interests (31 ) (1.4 )% — — (31 ) (1.0 )% Other, net (52 ) (2.3 )% 7 0.8 % (45 ) (1.4 )% Income tax expense (benefit) $ (1,160 ) (50.9 )% $ 211 22.9 % $ (949 ) (29.7 )% Year Ended December 31, 2016 U.S. International Total Amount Percent Amount Percent Amount Percent Income tax expense at statutory rates $ 606 35.0 % $ 256 17.7 % $ 862 27.1 % U.S. state and Canadian provincial tax expense, net of federal income tax effect 5 0.3 % 31 2.1 % 36 1.1 % Permanent differences: Manufacturing deduction (22 ) (1.3 )% — — (22 ) (0.7 )% Other (3 ) (0.2 )% (10 ) (0.7 )% (13 ) (0.4 )% Change in tax law — — (7 ) (0.5 )% (7 ) (0.2 )% Tax effects of income associated with noncontrolling interests (44 ) (2.5 )% — — (44 ) (1.4 )% Other, net (37 ) (2.1 )% (10 ) (0.7 )% (47 ) (1.5 )% Income tax expense $ 505 29.2 % $ 260 17.9 % $ 765 24.0 % Year Ended December 31, 2015 U.S. International Total Amount Percent Amount Percent Amount Percent Income tax expense at statutory rates $ 1,864 35.0 % $ 92 14.3 % $ 1,956 32.8 % U.S. state and Canadian provincial tax expense, net of federal income tax effect 45 0.8 % 73 11.3 % 118 2.0 % Permanent differences: Manufacturing deduction (102 ) (1.9 )% — — (102 ) (1.7 )% Other (18 ) (0.3 )% (5 ) (0.8 )% (23 ) (0.4 )% Change in tax law — — (17 ) (2.6 )% (17 ) (0.3 )% Tax effects of income associated with noncontrolling interests (39 ) (0.7 )% — — (39 ) (0.7 )% Other, net (25 ) (0.5 )% 2 0.3 % (23 ) (0.4 )% Income tax expense $ 1,725 32.4 % $ 145 22.5 % $ 1,870 31.3 % Components of income tax expense (benefit) related to our operations were as follows (in millions): Year Ended December 31, 2017 U.S. International Total Current: Country $ 1,305 $ 194 $ 1,499 U.S. state / Canadian provincial 34 61 95 Total current 1,339 (a) 255 1,594 Deferred: Country (2,522 ) (29 ) (2,551 ) U.S. state / Canadian provincial 23 (15 ) 8 Total deferred (2,499 ) (b) (44 ) (2,543 ) Income tax expense (benefit) $ (1,160 ) $ 211 $ (949 ) ___________________________ See notes on page 116 . Year Ended December 31, 2016 U.S. International Total Current: Country $ 294 $ 194 $ 488 U.S. state / Canadian provincial 12 35 47 Total current 306 229 535 Deferred: Country 203 35 238 U.S. state / Canadian provincial (4 ) (4 ) (8 ) Total deferred 199 31 230 Income tax expense $ 505 $ 260 $ 765 Year Ended December 31, 2015 U.S. International Total Current: Country $ 1,513 $ 64 $ 1,577 U.S. state / Canadian provincial 85 43 128 Total current 1,598 107 1,705 Deferred: Country 143 8 151 U.S. state / Canadian provincial (16 ) 30 14 Total deferred 127 38 165 Income tax expense $ 1,725 $ 145 $ 1,870 ___________________________ (a) Current income tax expense includes the effect of our $781 million Tax Reform adjustment as described in “Tax Reform” above. (b) Deferred income tax benefit includes the effect of our $2.6 billion Tax Reform adjustment as described in “Tax Reform” above. Income Taxes Paid Income taxes paid to U.S. and international taxing authorities were as follows (in millions): Year Ended December 31, 2017 2016 2015 U.S. $ 239 $ 241 $ 2,092 International 171 203 1 Income taxes paid, net $ 410 $ 444 $ 2,093 Deferred Income Tax Assets and Liabilities The tax effects of significant temporary differences representing deferred income tax assets and liabilities were as follows (in millions): December 31, 2017 2016 Deferred income tax assets: Tax credit carryforwards $ 69 $ 65 Net operating losses (NOLs) 492 374 Inventories 135 93 Compensation and employee benefit liabilities 179 344 Environmental liabilities 47 69 Other 112 100 Total deferred income tax assets 1,034 1,045 Valuation allowance (498 ) (374 ) Net deferred income tax assets 536 671 Deferred income tax liabilities: Property, plant, and equipment 4,545 6,900 Deferred turnaround costs 272 450 Inventories 243 356 Investments 77 253 Other 107 73 Total deferred income tax liabilities 5,244 8,032 Net deferred income tax liabilities $ 4,708 $ 7,361 Our deferred income tax assets and liabilities as of December 31, 2017 were impacted by the remeasurement of our U.S. temporary differences using the 21 percent statutory income tax rate as more fully described in “Tax Reform” above and “Details of the Tax Reform Adjustment” below. We had the following income tax credit and loss carryforwards as of December 31, 2017 (in millions): Amount Expiration U.S. state income tax credits $ 76 2018 through 2031 U.S. state income tax credits 11 Unlimited U.S. state NOLs (gross amount) 9,441 2018 through 2037 We have recorded a valuation allowance as of December 31, 2017 and 2016 due to uncertainties related to our ability to utilize some of our deferred income tax assets, primarily consisting of certain U.S. state income tax credits and NOLs, before they expire. The valuation allowance is based on our estimates of taxable income in the various jurisdictions in which we operate and the period over which deferred income tax assets will be recoverable. During 2017 , the valuation allowance increased by $124 million , primarily due to increases in State NOLs. The realization of net deferred income tax assets recorded as of December 31, 2017 is primarily dependent upon our ability to generate future taxable income in certain U.S. states. As described in “Tax Reform” above, one of the most significant changes in Tax Reform is the shift from a worldwide system of taxation to a territorial system. The shift to a territorial system allows us to distribute cash via a dividend from our international subsidiaries with a full dividend received deduction. As a result, we will not recognize U.S. federal deferred taxes for the future tax consequences attributable to differences between financial statement carrying amounts of existing assets and liabilities and the respective tax basis for our international subsidiaries. As of December 31, 2017 , we recognized a one-time transition tax of $734 million on approximately $4.7 billion of combined earnings and profits of our international subsidiaries. Because of the deemed repatriation of these accumulated earnings and profits, there are no longer any U.S. federal income tax consequences associated with the repatriation of any of the $3.2 billion of cash and temporary cash investments held by our international subsidiaries as of December 31, 2017 . However, certain countries in which our international subsidiaries are organized impose withholding taxes on cash distributed outside of those countries. We have accrued for withholding taxes on a portion of the cash held by one of our international subsidiaries that we have deemed to not be permanently reinvested in our operations in that country. Details of the Tax Reform Adjustment The following table details the components of our adjustment (in millions) to reflect the effects of Tax Reform for the year ended December 31, 2017 , including (i) whether such amounts are complete, provisional, or incomplete, and (ii) the additional information that we need to obtain in order to complete the accounting as required by SAB 118. See “Tax Reform” above for a discussion of the provisions of SAB 118. Accounting Status Amount Income tax benefit from the remeasurement of U.S. deferred income tax assets and liabilities Complete $ (2,643 ) Tax on the deemed repatriation of the accumulated earnings and profits of our international subsidiaries Provisional 734 Recognition of foreign withholding tax, net of U.S. federal tax benefit Complete 47 Deductibility of certain executive compensation expense Incomplete — Income tax expense associated with the statutory income tax rate differential on accrual to return adjustments that may be identified upon completion of our U.S. federal income tax return in 2018 Incomplete — Foreign tax credit available to offset the tax on deemed repatriation of the accumulated earnings and profits of our international subsidiaries Incomplete — Estimated Tax Reform benefit $ (1,862 ) We recorded a provisional amount of $734 million for the tax on the deemed repatriation of the accumulated earnings and profits of our international subsidiaries. We continue to gather additional information in order to more accurately compute this tax. Any associated U.S. state taxes will be recorded once the federal estimate is finalized. We anticipate this information will be available in the second half of 2018. Our accounting for the following items of Tax Reform are incomplete, and we have not yet been able to make reasonable estimates of the effects of these items. Therefore, no provisional amounts were recorded. • Deductibility of certain executive compensation : It is unclear from Tax Reform if the future payments related to existing deferred compensation plans to the covered executives will be subject to the $1 million deduction limitation or if such plans are considered grandfathered. We currently have deferred tax assets related to certain benefit plans that may be determined to be subject to the excess compensation limitations; however, the impact is not expected to be material. Additional clarifying guidance from the IRS is necessary to determine the proper treatment, and we expect such guidance will be released by the IRS in the near future. • Tax rate differential amount related to accrual to return adjustments : We use estimates to compute certain adjustments related to current and deferred income taxes. Upon the filing of our U.S. federal income tax return in the third quarter of 2018, adjustments will be recorded in our financial statements to reflect our actual payment. The U.S. tax rate differential ( 35 percent for current vs. 21 percent for deferred items) cannot be practically estimated until such true-up adjustments are known. • Foreign tax credits on deemed repatriation amount : Additional information is required to determine the amount of available foreign tax credits, if any, that can be used to reduce our tax on the deemed repatriation of the accumulated earnings and profits of our international subsidiaries. This includes information needed to compute any foreign tax credit limitations and information to accurately compute the income taxes paid from our various foreign subsidiaries. We anticipate this information will be available in the second half of 2018. Other significant Tax Reform provisions that are not yet effective, but may impact our income tax expense in future years include: • an exemption from U.S. tax on dividends of future foreign earnings; • a limitation on the current deductibility of net interest expense in excess of 30 percent of adjusted taxable income; • a limitation of net operating losses generated after fiscal 2018 to 80 percent of taxable income; • an incremental tax (base erosion anti-abuse tax, or BEAT) on excessive amounts paid to international related parties; • a minimum tax on certain foreign earnings in excess of 10 percent of the international subsidiaries’ tangible assets (the GILTI tax); and • a deduction equal to 37.5 percent of our foreign-derived intangible income. We are still evaluating whether to make a policy election to treat the GILTI tax as a period expense or to provide U.S. deferred taxes on temporary differences that are expected to generate GILTI income when they reverse in future years. Unrecognized Tax Benefits The following is a reconciliation of the change in unrecognized tax benefits, excluding related penalties and interest, (in millions): Year Ended December 31, 2017 2016 2015 Balance as of beginning of year $ 936 $ 964 $ 989 Additions based on tax positions related to the current year 33 36 36 Additions for tax positions related to prior years 15 11 83 Reductions for tax positions related to prior years (42 ) (46 ) (82 ) Reductions for tax positions related to the lapse of applicable statute of limitations (1 ) (3 ) (3 ) Settlements — (237 ) (59 ) Reclassification of uncertain tax receivable to long-term receivable from IRS — 211 — Balance as of end of year $ 941 $ 936 $ 964 As of December 31, 2017 , the balance in unrecognized tax benefits included $274 million of tax refunds that we intend to claim by amending various of our income tax returns for 2010 through 2016. We intend to propose that incentive payments received from the U.S. federal government for blending biofuels into refined petroleum products be excluded from taxable income during these periods. However, due to the complexity of this matter and uncertainties with respect to the interpretation of the Code, we concluded that the refund claims included in the following table cannot be recognized in our financial statements. As a result, these amounts are not included in our uncertain tax position liabilities as of December 31, 2017 , 2016 , and 2015 even though they are reflected in the preceding table. The following is a reconciliation of unrecognized tax benefits reflected in the preceding table to our uncertain tax position liabilities that are presented in our balance sheets (in millions). December 31, 2017 2016 Unrecognized tax benefits $ 941 $ 936 Tax refund claim not presented in our balance sheets (274 ) (433 ) Other 77 (5 ) Uncertain tax position liabilities presented in our balance sheets $ 744 $ 498 Amounts recognized in our balance sheets for uncertain tax positions include (in millions): December 31, 2017 2016 Income taxes payable $ — $ (7 ) Other long-term liabilities (723 ) (465 ) Deferred tax liabilities (21 ) (26 ) Uncertain tax position liabilities presented in our balance sheets $ (744 ) $ (498 ) As of December 31, 2017 and 2016 , there were $793 million and $756 million , respectively, of unrecognized tax benefits that if recognized would affect our annual effective tax rate. Penalties and interest during the years ended December 31, 2017 , 2016 , and 2015 were immaterial. Accrued penalties and interest totaled $77 million and $70 million as of December 31, 2017 and 2016 , respectively, excluding the U.S. federal and state income tax effects related to interest. During the next 12 months, it is reasonably possible that tax audit resolutions could reduce unrecognized tax benefits, excluding interest, either because the tax positions are sustained on audit or because we agree to their disallowance. We do not expect these reductions to have a significant impact on our financial statements because such reductions would not significantly affect our annual effective tax rate. U.S. Tax Returns Under Audit Federal As of December 31, 2017 , our tax years for 2010 through 2015 were under audit by the IRS. The IRS has proposed adjustments to our taxable income for certain open years. We are currently contesting the proposed adjustments with the Office of Appeals of the IRS for certain open years and do not expect that the ultimate disposition of these adjustments will result in a material change to our financial position, results of operations, or liquidity. We are continuing to work with the IRS to resolve these matters and we believe that they will be resolved for amounts consistent with recorded amounts of unrecognized tax benefits associated with these matters. State As of December 31, 2017 , our tax years for 2004 through 2008 and 2011 through 2014 were under audit by the state of California for certain tax issues. We do not expect the ultimate disposition of these issues will result in a material change to our financial position, results of operations, or liquidity. We believe these matters will be resolved for amounts consistent with our recorded amounts of unrecognized tax benefits associated with these matters.

Earnings Per Common Share

Earnings Per Common Share	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
EARNINGS PER COMMON SHARE	15. EARNINGS PER COMMON SHARE Earnings per common share were computed as follows (dollars and shares in millions, except per share amounts): Year Ended December 31, 2017 2016 2015 Participating Common Stock Participating Common Stock Participating Common Stock Earnings per common share: Net income attributable to Valero stockholders $ 4,065 $ 2,289 $ 3,990 Less dividends paid: Common stock 1,238 1,108 845 Participating securities 4 3 3 Undistributed earnings $ 2,823 $ 1,178 $ 3,142 Weighted-average common shares outstanding 2 442 1 461 2 497 Earnings per common share: Distributed earnings $ 2.80 $ 2.80 $ 2.40 $ 2.40 $ 1.70 $ 1.70 Undistributed earnings 6.37 6.37 2.54 2.54 6.30 6.30 Total earnings per common share $ 9.17 $ 9.17 $ 4.94 $ 4.94 $ 8.00 $ 8.00 Earnings per common share – assuming dilution: Net income attributable to Valero stockholders $ 4,065 $ 2,289 $ 3,990 Weighted-average common shares outstanding 442 461 497 Common equivalent shares 2 3 3 Weighted-average common shares outstanding – assuming dilution 444 464 500 Earnings per common share – assuming dilution $ 9.16 $ 4.94 $ 7.99 Participating securities include restricted stock and performance awards granted under our 2011 Omnibus Stock Incentive Plan.

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
SEGMENT INFORMATION	16. SEGMENT INFORMATION Effective January 1, 2017, we revised our reportable segments to align with certain changes in how our chief operating decision maker manages and allocates resources to our business. Accordingly, we created a new reportable segment — VLP. The results of the VLP segment, which include the results of our majority-owned master limited partnership referred to by the same name, were transferred from the refining segment. Our prior period segment information has been retrospectively adjusted to reflect our current segment presentation. As a result, we have three reportable segments as follows: • Refining segment includes our refining operations, the associated marketing activities, and certain logistics assets, which are not owned by VLP, that support our refining operations; • Ethanol segment includes our ethanol operations, the associated marketing activities, and logistics assets that support our ethanol operations; and • VLP segment includes the results of VLP, which provides transportation and terminaling services to our refining segment. Operations that are not included in any of the reportable segments are included in the corporate category. Our reportable segments are strategic business units that offer different products and services. They are managed separately as each business requires unique technologies and marketing strategies. Performance is evaluated based on segment operating income, which includes revenues and expenses that are directly attributable to the management of the respective segment. Intersegment sales are generally derived from transactions made at prevailing market rates. The following table reflects activity related to our reportable segments (in millions): Refining Ethanol VLP Corporate and Eliminations Total Year ended December 31, 2017: Operating revenues: Operating revenues from external customers $ 90,651 $ 3,324 $ — $ 5 $ 93,980 Intersegment revenues 6 176 452 (634 ) — Total operating revenues 90,657 3,500 452 (629 ) 93,980 Cost of sales: Cost of materials and other 80,865 2,804 — (632 ) 83,037 Operating expenses (excluding depreciation and amortization expense reflected below) 3,917 443 104 (2 ) 4,462 Depreciation and amortization expense 1,800 81 53 — 1,934 Total cost of sales 86,582 3,328 157 (634 ) 89,433 Other operating expenses 58 — 3 — 61 General and administrative expenses (excluding depreciation and amortization expense reflected below) — — — 835 835 Depreciation and amortization expense — — — 52 52 Operating income by segment $ 4,017 $ 172 $ 292 $ (882 ) $ 3,599 Total expenditures for long-lived assets $ 1,710 $ 84 $ 110 $ 44 $ 1,948 Year ended December 31, 2016: Operating revenues: Operating revenues from external customers $ 71,968 $ 3,691 $ — $ — $ 75,659 Intersegment revenues — 210 363 (573 ) — Total operating revenues 71,968 3,901 363 (573 ) 75,659 Cost of sales: Cost of materials and other 63,405 3,130 — (573 ) 65,962 Operating expenses (excluding depreciation and amortization expense reflected below) 3,696 415 96 — 4,207 Depreciation and amortization expense 1,734 66 46 — 1,846 Lower of cost or market inventory valuation adjustment (697 ) (50 ) — — (747 ) Total cost of sales 68,138 3,561 142 (573 ) 71,268 General and administrative expenses (excluding depreciation and amortization expense reflected below) — — — 715 715 Depreciation and amortization expense — — — 48 48 Asset impairment loss 56 — — — 56 Operating income by segment $ 3,774 $ 340 $ 221 $ (763 ) $ 3,572 Total expenditures for long-lived assets $ 1,867 $ 68 $ 23 $ 38 $ 1,996 Refining Ethanol VLP Corporate and Eliminations Total Year Ended December 31, 2015: Operating revenues: Operating revenues from external customers $ 84,521 $ 3,283 $ — $ — $ 87,804 Intersegment revenues — 151 244 (395 ) — Total operating revenues 84,521 3,434 244 (395 ) 87,804 Cost of sales: Cost of materials and other 71,512 2,744 — (395 ) 73,861 Operating expenses (excluding depreciation and amortization expense reflected below) 3,689 448 106 — 4,243 Depreciation and amortization expense 1,699 50 46 — 1,795 Lower of cost or market inventory valuation adjustment 740 50 — — 790 Total cost of sales 77,640 3,292 152 (395 ) 80,689 General and administrative expenses (excluding depreciation and amortization expense reflected below) — — — 710 710 Depreciation and amortization expense — — — 47 47 Operating income by segment $ 6,881 $ 142 $ 92 $ (757 ) $ 6,358 Total expenditures for long-lived assets $ 2,216 $ 67 $ 38 $ 29 $ 2,350 Our principal products include conventional and California Air Resources Board gasolines, RBOB (reformulated gasoline blendstock for oxygenate blending), gasoline blendstocks, ultra-low-sulfur diesel, middle distillates, and jet fuel. Other product revenues primarily include petrochemicals, gas oils, No. 6 fuel oil, petroleum coke, sulfur, and asphalt. Operating revenues from external customers by reportable segment for our principal products were as follows (in millions): Year Ended December 31, 2017 2016 2015 Refining: Gasolines and blendstocks $ 40,362 $ 33,450 $ 38,983 Distillates 42,074 32,576 38,093 Other product revenues 8,215 5,942 7,445 Total refining revenues 90,651 71,968 84,521 Ethanol: Ethanol 2,764 3,105 2,628 Distillers grains 560 586 655 Total ethanol revenues 3,324 3,691 3,283 Corporate – other revenues 5 — — Total revenues from external customers $ 93,980 $ 75,659 $ 87,804 Operating revenues by geographic area are shown in the following table (in millions). The geographic area is based on location of customer and no customer accounted for 10 percent or more of our operating revenues. Year Ended December 31, 2017 2016 2015 U.S. $ 66,614 $ 51,479 $ 60,319 Canada 7,039 6,115 6,841 U.K. and Ireland 11,556 10,797 11,232 Other countries 8,771 7,268 9,412 Total operating revenues $ 93,980 $ 75,659 $ 87,804 Long-lived assets include property, plant, and equipment and certain long-lived assets included in “deferred charges and other assets, net.” Long-lived assets by geographic area consisted of the following (in millions): December 31, 2017 2016 U.S. $ 26,083 $ 25,359 Canada 1,915 1,816 U.K. and Ireland 1,063 967 Total long-lived assets $ 29,061 $ 28,142 Total assets by reportable segment were as follows (in millions): December 31, 2017 2016 Refining $ 40,382 $ 38,095 Ethanol 1,344 1,316 VLP 1,517 979 Corporate and eliminations 6,915 5,783 Total assets $ 50,158 $ 46,173

Supplemental Cash Flow Informat

Supplemental Cash Flow Information	12 Months Ended
	Dec. 31, 2017
Supplemental Cash Flow Information [Abstract]
SUPPLEMENTAL CASH FLOW INFORMATION	17. SUPPLEMENTAL CASH FLOW INFORMATION In order to determine net cash provided by operating activities, net income is adjusted by, among other things, changes in current assets and current liabilities as follows (in millions): Year Ended December 31, 2017 2016 2015 Decrease (increase) in current assets: Receivables, net $ (870 ) $ (1,531 ) $ 1,294 Inventories (516 ) 771 (222 ) Prepaid expenses and other 151 47 (149 ) Increase (decrease) in current liabilities: Accounts payable 1,842 1,556 (1,787 ) Accrued expenses 21 117 (40 ) Taxes other than income taxes payable 172 82 (74 ) Income taxes payable 489 (66 ) (328 ) Changes in current assets and current liabilities $ 1,289 $ 976 $ (1,306 ) Cash flows related to interest and income taxes were as follows (in millions): Year Ended December 31, 2017 2016 2015 Interest paid in excess of amount capitalized $ 457 $ 427 $ 416 Income taxes paid, net 410 444 2,093 Cash flows reflected as “other financing activities, net” for the year ended December 31, 2016 included the payment of a long-term liability of $137 million owed to a joint venture partner associated with an owner-method joint venture investment. Noncash investing and financing activities for the year ended December 31, 2017 included the recognition of (i) a capital lease asset and related obligation associated with an agreement for storage tanks near three of our refineries as described in Note 8 and (ii) terminal assets and related obligation recorded under owner accounting as described in Note 9 . There were no significant noncash investing and financing activities for the year ended December 31, 2016 . Noncash investing and financing activities for the year ended December 31, 2015 included the recognition of a capital lease asset and related obligation associated with an agreement for storage tanks near one of our refineries.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
FAIR VALUE MEASUREMENTS	18. FAIR VALUE MEASUREMENTS General U.S. GAAP requires or permits certain assets and liabilities to be measured at fair value on a recurring or nonrecurring basis in our balance sheets, and those assets and liabilities are presented below under “Recurring Fair Value Measurements” and “Nonrecurring Fair Value Measurements.” Assets and liabilities measured at fair value on a recurring basis, such as derivative financial instruments, are measured at fair value at the end of each reporting period. Assets and liabilities measured at fair value on a nonrecurring basis, such as the impairment of property, plant and equipment, are measured at fair value in particular circumstances. U.S. GAAP also requires the disclosure of the fair values of financial instruments when an option to elect fair value accounting has been provided, but such election has not been made. A debt obligation is an example of such a financial instrument. The disclosure of the fair values of financial instruments not recognized at fair value in our balance sheet is presented below under “Other Financial Instruments.” U.S. GAAP provides a framework for measuring fair value and establishes a three-level fair value hierarchy that prioritizes inputs to valuation techniques based on the degree to which objective prices in external active markets are available to measure fair value. Following is a description of each of the levels of the fair value hierarchy. • Level 1 - Observable inputs, such as unadjusted quoted prices in active markets for identical assets or liabilities. • Level 2 - Inputs other than quoted prices included within Level 1 that are observable for the asset or liability, either directly or indirectly. These include quoted prices for similar assets or liabilities in active markets and quoted prices for identical or similar assets or liabilities in markets that are not active. • Level 3 - Unobservable inputs for the asset or liability. Unobservable inputs reflect our own assumptions about what market participants would use to price the asset or liability. The inputs are developed based on the best information available in the circumstances, which might include occasional market quotes or sales of similar instruments or our own financial data such as internally developed pricing models, discounted cash flow methodologies, as well as instruments for which the fair value determination requires significant judgment. Recurring Fair Value Measurements The following tables present information (in millions) about our assets and liabilities recognized at their fair values in our balance sheets categorized according to the fair value hierarchy of the inputs utilized by us to determine the fair values as of December 31, 2017 and 2016 . We have elected to offset the fair value amounts recognized for multiple similar derivative contracts executed with the same counterparty, including any related cash collateral assets or obligations as shown below; however, fair value amounts by hierarchy level are presented in the following tables on a gross basis. We have no derivative contracts that are subject to master netting arrangements that are reflected gross on the balance sheet. December 31, 2017 Total Gross Fair Value Effect of Counter- party Netting Effect of Cash Collateral Netting Net Carrying Value on Balance Sheet Cash Collateral Paid or Received Not Offset Fair Value Hierarchy Level 1 Level 2 Level 3 Assets: Commodity derivative contracts $ 875 $ 19 $ — $ 894 $ (893 ) $ — $ 1 $ — Investments of certain benefit plans 65 — 8 73 n/a n/a 73 n/a Total $ 940 $ 19 $ 8 $ 967 $ (893 ) $ — $ 74 Liabilities: Commodity derivative contracts $ 955 $ 14 $ — $ 969 $ (893 ) $ (76 ) $ — $ (102 ) Environmental credit obligations — 104 — 104 n/a n/a 104 n/a Physical purchase contracts — 6 — 6 n/a n/a 6 n/a Foreign currency contracts 7 — — 7 n/a n/a 7 n/a Total $ 962 $ 124 $ — $ 1,086 $ (893 ) $ (76 ) $ 117 December 31, 2016 Total Gross Fair Value Effect of Counter- party Netting Effect of Cash Collateral Netting Net Carrying Value on Balance Sheet Cash Collateral Paid or Received Not Offset Fair Value Hierarchy Level 1 Level 2 Level 3 Assets: Commodity derivative contracts $ 874 $ 38 $ — $ 912 $ (875 ) $ — $ 37 $ — Foreign currency contracts 3 — — 3 n/a n/a 3 n/a Investments of certain benefit plans 58 — 11 69 n/a n/a 69 n/a Total $ 935 $ 38 $ 11 $ 984 $ (875 ) $ — $ 109 Liabilities: Commodity derivative contracts $ 872 $ 23 $ — $ 895 $ (875 ) $ (20 ) $ — $ (88 ) Environmental credit obligations — 188 — 188 n/a n/a 188 n/a Physical purchase contracts — 5 — 5 n/a n/a 5 n/a Total $ 872 $ 216 $ — $ 1,088 $ (875 ) $ (20 ) $ 193 A description of our assets and liabilities recognized at fair value along with the valuation methods and inputs we used to develop their fair value measurements are as follows: • Commodity derivative contracts consist primarily of exchange-traded futures and swaps, and as disclosed in Note 19 , some of these contracts are designated as hedging instruments. These contracts are measured at fair value using the market approach. Exchange-traded futures are valued based on quoted prices from the exchange and are categorized in Level 1 of the fair value hierarchy. Swaps are priced using third-party broker quotes, industry pricing services, and exchange-traded curves, with appropriate consideration of counterparty credit risk, but because they have contractual terms that are not identical to exchange-traded futures instruments with a comparable market price, these financial instruments are categorized in Level 2 of the fair value hierarchy. • Physical purchase contracts represent the fair value of fixed-price corn purchase contracts. The fair values of these purchase contracts are measured using a market approach based on quoted prices from the commodity exchange or an independent pricing service and are categorized in Level 2 of the fair value hierarchy. • Investments of certain benefit plans consist of investment securities held by trusts for the purpose of satisfying a portion of our obligations under certain U.S. nonqualified benefit plans. The assets categorized in Level 1 of the fair value hierarchy are measured at fair value using a market approach based on quoted prices from national securities exchanges. The assets categorized in Level 3 of the fair value hierarchy represent insurance contracts, the fair value of which is provided by the insurer. • Foreign currency contracts consist of foreign currency exchange and purchase contracts entered into for our international operations to manage our exposure to exchange rate fluctuations on transactions denominated in currencies other than the local (functional) currencies of those operations. These contracts are valued based on quoted prices from the exchange and are categorized in Level 1 of the fair value hierarchy. • Environmental credit obligations represent our liability for the purchase of (i) biofuel credits (primarily RINs in the U.S.) needed to satisfy our obligation to blend biofuels into the products we produce and (ii) emission credits under the California Global Warming Solutions Act (the California cap-and-trade system, also known as AB 32), Quebec’s Environmental Quality Act (the Quebec cap-and-trade system), and Ontario’s Climate Change Mitigation and Low-Carbon Economy Act (the Ontario cap-and-trade system), (collectively, the cap-and-trade systems). To the degree we are unable to blend biofuels (such as ethanol and biodiesel) at percentages required under the biofuel programs, we must purchase biofuel credits to comply with these programs. Under the cap-and-trade systems, we must purchase emission credits to comply with these systems. These programs are further described in Note 19 under “Environmental Compliance Program Price Risk.” The liability for environmental credits is based on our deficit for such credits as of the balance sheet date, if any, after considering any credits acquired or under contract, and is equal to the product of the credits deficit and the market price of these credits as of the balance sheet date. The environmental credit obligations are categorized in Level 2 of the fair value hierarchy and are measured at fair value using the market approach based on quoted prices from an independent pricing service. There were no transfers between levels for assets and liabilities held as of December 31, 2017 and 2016 that were measured at fair value on a recurring basis. There was no significant activity during the years ended December 31, 2017 , 2016 , and 2015 related to the fair value amounts categorized in Level 3 as of December 31, 2017 , 2016 , and 2015 . Nonrecurring Fair Value Measurements As discussed in Note 2 , we concluded that the Aruba Terminal was impaired as of June 30, 2016, which resulted in an asset impairment loss of $56 million that was recorded in June 2016. The fair value of the Aruba Terminal was determined using an income approach and was classified in Level 3. We employed a probability-weighted approach to possible future cash flow scenarios, including transferring ownership of the business to the GOA or continuing to operate the business. There were no assets or liabilities that were measured at fair value on a nonrecurring basis as of December 31, 2017 and 2016 . Other Financial Instruments Financial instruments that we recognize in our balance sheets at their carrying amounts are shown in the following table along with their associated fair values (in millions): December 31, 2017 December 31, 2016 Carrying Amount Fair Value Carrying Amount Fair Value Financial assets: Cash and temporary cash investments $ 5,850 $ 5,850 $ 4,816 $ 4,816 Financial liabilities: Debt (excluding capital leases) 8,310 9,795 7,926 8,882 The methods and significant assumptions used to estimate the fair value of these financial instruments are as follows: • The fair value of cash and temporary cash investments approximates the carrying value due to the low level of credit risk of these assets combined with their short maturities and market interest rates (Level 1). • The fair value of debt is determined primarily using the market approach based on quoted prices provided by third-party brokers and vendor pricing services (Level 2).

Price Risk Management Activitie

Price Risk Management Activities	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
PRICE RISK MANAGEMENT ACTIVITIES	19. PRICE RISK MANAGEMENT ACTIVITIES We are exposed to market risks primarily related to the volatility in the price of commodities, and foreign currency exchange rates, and the price of credits needed to comply with various government and regulatory programs. We enter into derivative instruments to manage some of these risks, including derivative instruments related to the various commodities we purchase or produce, and foreign currency exchange and purchase contracts, as described below under “Risk Management Activities by Type of Risk.” These derivative instruments are recorded as either assets or liabilities measured at their fair values (see Note 18 ), as summarized below under “Fair Values of Derivative Instruments,” with changes in fair value recognized currently in income. The effect of these derivative instruments on our income is summarized below under “Effect of Derivative Instruments on Income.” Risk Management Activities by Type of Risk Commodity Price Risk We are exposed to market risks related to the volatility in the price of crude oil, refined petroleum products (primarily gasoline and distillate), grain (primarily corn), soybean oil, and natural gas used in our operations. To reduce the impact of price volatility on our results of operations and cash flows, we use commodity derivative instruments, including futures, swaps, and options. We use the futures markets for the available liquidity, which provides greater flexibility in transacting our hedging and trading operations. We use swaps primarily to manage our price exposure. Our positions in commodity derivative instruments are monitored and managed on a daily basis by our risk control group to ensure compliance with our stated risk management policy that has been approved by our board of directors. To manage commodity price risk, we use economic hedges, which are not designated as fair value or cash flow hedges, and we use fair value and cash flow hedges from time to time. We also enter into certain commodity derivative instruments for trading purposes. Our objectives for entering into hedges or trading derivatives are described below. • Economic Hedges – Economic hedges represent commodity derivative instruments that are used to manage price volatility in certain (i) feedstock and refined petroleum product inventories, (ii) fixed-price purchase contracts, and (iii) forecasted feedstock, refined petroleum product or natural gas purchases and refined petroleum product sales. The objectives of our economic hedges are to hedge price volatility in certain feedstock and refined petroleum product inventories and to lock in the price of forecasted feedstock, refined petroleum product, or natural gas purchases or refined petroleum product sales at existing market prices that we deem favorable. Economic hedges are not designated as fair value or cash flow hedges for accounting purposes, usually due to the difficulty of establishing the required documentation at the date the derivative instrument is entered into for them to qualify as hedging instruments for accounting purposes. As of December 31, 2017 , we had the following outstanding commodity derivative instruments that were used as economic hedges, as well as commodity derivative instruments related to the physical purchase of corn at a fixed price. The information presents the notional volume of outstanding contracts by type of instrument and year of maturity (volumes in thousands of barrels, except those identified as corn contracts that are presented in thousands of bushels and soybean oil contracts that are presented in thousands of pounds). Notional Contract Volumes by Year of Maturity Derivative Instrument 2018 2019 Crude oil and refined petroleum products: Swaps – long 2,655 — Swaps – short 2,590 — Futures – long 83,296 — Futures – short 87,542 — Corn: Futures – long 21,315 35 Futures – short 50,695 665 Physical contracts – long 25,103 630 Soybean oil: Futures – long 76,079 — Futures – short 154,378 — • Trading Derivatives – Our objective for entering into commodity derivative instruments for trading purposes is to take advantage of existing market conditions for crude oil and refined petroleum products. As of December 31, 2017 , we had the following outstanding commodity derivative instruments that were entered into for trading purposes. The information presents the notional volume of outstanding contracts by type of instrument and year of maturity (volumes in thousands of barrels, except those identified as corn contracts that are presented in thousands of bushels). Notional Contract Volumes by Year of Maturity Derivative Instrument 2018 2019 Crude oil and refined petroleum products: Swaps – long 659 — Swaps – short 659 — Futures – long 37,532 — Futures – short 36,919 150 Options – long 153,050 — Options – short 153,050 — Corn: Futures – long 300 — We had no commodity derivative contracts outstanding as of December 31, 2017 and 2016 or during the years ended December 31, 2017 and 2016 that were designated as fair value or cash flow hedges. Foreign Currency Risk We are exposed to exchange rate fluctuations on transactions entered into by our international operations that are denominated in currencies other than the local (functional) currencies of these operations. To manage our exposure to these exchange rate fluctuations, we use foreign currency exchange and purchase contracts. These contracts are not designated as hedging instruments for accounting purposes and therefore are classified as economic hedges. As of December 31, 2017 , we had forward contracts to purchase $507 million of U.S. dollars. These commitments matured on or before January 31, 2018 . Environmental Compliance Program Price Risk We are exposed to market risk related to the volatility in the price of credits needed to comply with various governmental and regulatory environmental compliance programs. To manage this risk, we enter into contracts to purchase these credits when prices are deemed favorable. Some of these contracts are derivative instruments; however, we elect the normal purchase exception and do not record these contracts at their fair values. Certain of these programs require us to blend biofuels into the products we produce, and we are subject to such programs in most of the countries in which we operate. These countries set annual quotas for the percentage of biofuels that must be blended into the motor fuels consumed in these countries. As a producer of motor fuels from petroleum, we are obligated to blend biofuels into the products we produce at a rate that is at least equal to the applicable quota. To the degree we are unable to blend at the applicable rate, we must purchase biofuel credits (primarily RINs in the U.S.). We are exposed to the volatility in the market price of these credits, and we manage that risk by purchasing biofuel credits when prices are deemed favorable. For the years ended December 31, 2017 , 2016 , and 2015 , the cost of meeting our obligations under these compliance programs was $942 million , $749 million , and $440 million , respectively. These amounts are reflected in cost of materials and other. We are subject to additional requirements under GHG emission programs, including the cap-and-trade systems, as discussed in Note 18 . Under these cap-and-trade systems, we purchase various GHG emission credits available on the open market. Therefore, we are exposed to the volatility in the market price of these credits. The cost to implement certain provisions of the cap-and-trade systems are significant; however, we recovered the majority of these costs from our customers for the years ended December 31, 2017 , 2016 , and 2015 and expect to continue to recover the majority of these costs in the future. For the years ended December 31, 2017 , 2016 , and 2015 , the net cost of meeting our obligations under these compliance programs was immaterial. Fair Values of Derivative Instruments The following tables provide information about the fair values of our derivative instruments as of December 31, 2017 and 2016 (in millions) and the line items in the balance sheets in which the fair values are reflected. See Note 18 for additional information related to the fair values of our derivative instruments. As indicated in Note 18 , we net fair value amounts recognized for multiple similar derivative contracts executed with the same counterparty under master netting arrangements, including cash collateral assets and obligations. The following tables, however, are presented on a gross asset and gross liability basis, which results in the reflection of certain assets in liability accounts and certain liabilities in asset accounts. Balance Sheet Location December 31, 2017 Asset Derivatives Liability Derivatives Derivatives not designated as hedging instruments Commodity contracts: Futures Receivables, net $ 875 $ 955 Swaps Receivables, net 11 11 Options Receivables, net 8 3 Physical purchase contracts Inventories — 6 Foreign currency contracts Accrued expenses — 7 Total $ 894 $ 982 Balance Sheet Location December 31, 2016 Asset Derivatives Liability Derivatives Derivatives not designated as hedging instruments Commodity contracts: Futures Receivables, net $ 874 $ 872 Swaps Receivables, net 32 21 Options Receivables, net 6 2 Physical purchase contracts Inventories — 5 Foreign currency contracts Receivables, net 3 — Total $ 915 $ 900 Market Risk Our price risk management activities involve the receipt or payment of fixed price commitments into the future. These transactions give rise to market risk, which is the risk that future changes in market conditions may make an instrument less valuable. We closely monitor and manage our exposure to market risk on a daily basis in accordance with policies approved by our board of directors. Market risks are monitored by our risk control group to ensure compliance with our stated risk management policy. We do not require any collateral or other security to support derivative instruments into which we enter. We also do not have any derivative instruments that require us to maintain a minimum investment-grade credit rating. Effect of Derivative Instruments on Income The following tables provide information about the gain or loss recognized in income on our derivative instruments and the income statement line items in which such gains and losses are reflected (in millions). Derivatives Designated as Economic Hedges Location of Gain (Loss) Recognized in Income on Derivatives Year Ended December 31, 2017 2016 2015 Commodity contracts Cost of materials and other $ (344 ) $ (132 ) $ 377 Foreign currency contracts Cost of materials and other (40 ) 16 49 Trading Derivatives Location of Gain Recognized in Income on Derivatives Year Ended December 31, 2017 2016 2015 Commodity contracts Cost of materials and other $ 66 $ 46 $ 45

Quarterly Financial Data (Unaud

Quarterly Financial Data (Unaudited)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
QUARTERLY FINANCIAL DATA (Unaudited)	20. QUARTERLY FINANCIAL DATA (Unaudited) The following table summarizes quarterly financial data for the years ended December 31, 2017 and 2016 (in millions, except per share amounts). 2017 Quarter Ended March 31 June 30 September 30 December 31 (b) Operating revenues $ 21,772 $ 22,254 $ 23,562 $ 26,392 Gross profit (a) 739 1,063 1,624 1,121 Operating income 537 871 1,338 853 Net income 321 572 863 2,400 Net income attributable to Valero Energy Corporation stockholders 305 548 841 2,371 Earnings per common share 0.68 1.23 1.91 5.43 Earnings per common share – assuming dilution 0.68 1.23 1.91 5.42 2016 Quarter Ended March 31 (c) June 30 (d) September 30 (e) December 31 Operating revenues $ 15,714 $ 19,584 $ 19,649 $ 20,712 Gross profit (a) 997 1,457 1,096 841 Operating income 829 1,231 892 620 Net income 513 843 645 416 Net income attributable to Valero Energy Corporation stockholders 495 814 613 367 Earnings per common share 1.05 1.74 1.33 0.81 Earnings per common share – assuming dilution 1.05 1.73 1.33 0.81 ___________________________ (a) Gross profit is calculated as operating revenues less total cost of sales. (b) During the quarter ended December 31, 2017 , we recognized an income tax benefit of $1.9 billion related to Tax Reform as described in Note 14 . (c) During the quarter ended March 31, 2016, we recognized a favorable noncash lower of cost or market inventory valuation adjustment of $293 million as described in Note 4 . (d) During the quarter ended June 30, 2016, we recognized a favorable noncash lower of cost or market inventory valuation adjustment of $454 million as described in Note 4 and an asset impairment loss of $56 million related to the Aruba Disposition as described in Note 2 . (e) During the quarter ended September 30, 2016, we recognized a tax benefit of $42 million related to the Aruba Disposition as described in Note 2 .

Description of Business, Basi29

Description of Business, Basis of Presentation, and Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation General These consolidated financial statements were prepared in accordance with U.S. generally accepted accounting principles (GAAP) and with the rules and regulations of the U.S. Securities and Exchange Commission (SEC).
Reclassifications	Reclassifications Effective January 1, 2017, we revised our reportable segments to reflect a new reportable segment — VLP. The results of the VLP segment include the results of VLP, our majority-owned master limited partnership. Our prior period segment information has been retrospectively adjusted to reflect our current segment presentation. See Note 16 for additional information. Certain prior year amounts have been reclassified to conform to the 2017 presentation. The changes were primarily due to the separate presentation of depreciation and amortization expense related to operating expenses and general and administrative expenses.
Principles of Consolidation	Principles of Consolidation These financial statements include those of Valero, our wholly owned subsidiaries, and variable interest entities (VIEs) in which we have a controlling interest. Our VIEs are described in Note 11 . The ownership interests held by others in the VIEs are recorded as noncontrolling interests. Intercompany items and transactions have been eliminated in consolidation. Investments in less than wholly owned entities where we have significant influence are accounted for using the equity method.
Use of Estimates	Use of Estimates The preparation of financial statements in conformity with U.S. GAAP requires us to make estimates and assumptions that affect the amounts reported in the financial statements and accompanying notes. Actual results could differ from those estimates. On an ongoing basis, we review our estimates based on currently available information. Changes in facts and circumstances may result in revised estimates.
Temporary Cash Investments	Temporary Cash Investments Our temporary cash investments are highly liquid, low-risk debt instruments that have a maturity of three months or less when acquired.
Receivables	Receivables Trade receivables are carried at original invoice amount. We maintain an allowance for doubtful accounts, which is adjusted based on management’s assessment of our customers’ historical collection experience, known credit risks, and industry and economic conditions.
Inventories	Inventories The cost of refinery feedstocks, refined petroleum products, and grain and ethanol inventories is determined under the last-in, first-out (LIFO) method using the dollar-value LIFO approach, with any increments valued based on average purchase prices during the year. Our LIFO inventories are carried at the lower of cost or market. The cost of products purchased for resale and the cost of materials and supplies are determined principally under the weighted-average cost method. Our non-LIFO inventories are carried at the lower of cost or net realizable value. If the aggregate market value of our LIFO inventories or the aggregate net realizable value of our non-LIFO inventories is less than the related aggregate cost, we recognize a loss for the difference in our statements of income.
Property, Plant, and Equipment	Property, Plant, and Equipment The cost of property, plant, and equipment (property assets) purchased or constructed, including betterments of property assets, is capitalized. However, the cost of repairs to and normal maintenance of property assets is expensed as incurred. Betterments of property assets are those that extend the useful life, increase the capacity or improve the operating efficiency of the asset, or improve the safety of our operations. The cost of property assets constructed includes interest and certain overhead costs allocable to the construction activities. Our operations, especially those of our refining segment, are highly capital intensive. Each of our refineries comprises a large base of property assets, consisting of a series of interconnected, highly integrated and interdependent crude oil processing facilities and supporting logistical infrastructure (Units), and these Units are continuously improved. Improvements consist of the addition of new Units and betterments of existing Units. We plan for these improvements by developing a multi-year capital program that is updated and revised based on changing internal and external factors. Depreciation of property assets used in our refining segment is recorded on a straight-line basis over the estimated useful lives of these assets primarily using the composite method of depreciation. We maintain a separate composite group of property assets for each of our refineries. We estimate the useful life of each group based on an evaluation of the property assets comprising the group, and such evaluations consist of, but are not limited to, the physical inspection of the assets to determine their condition, consideration of the manner in which the assets are maintained, assessment of the need to replace assets, and evaluation of the manner in which improvements impact the useful life of the group. The estimated useful lives of our composite groups range primarily from 25 to 30 years. Under the composite method of depreciation, the cost of an improvement is added to the composite group to which it relates and is depreciated over that group’s estimated useful life. We design improvements to our refineries in accordance with engineering specifications, design standards, and practices accepted in our industry, and these improvements have design lives consistent with our estimated useful lives. Therefore, we believe the use of the group life to depreciate the cost of improvements made to the group is reasonable because the estimated useful life of each improvement is consistent with that of the group. Also under the composite method of depreciation, the historical cost of a minor property asset (net of salvage value) that is retired or replaced is charged to accumulated depreciation and no gain or loss is recognized in income. However, a gain or loss is recognized in income for a major property asset that is retired, replaced, sold, or for an abnormal disposition of a property asset (primarily involuntary conversions). Gains and losses are reflected in depreciation and amortization expense, unless such amounts are reported separately due to materiality. Depreciation of property assets used in our ethanol segment is recorded on a straight-line basis over the estimated useful lives of the related assets. Leasehold improvements are amortized on a straight-line basis over the shorter of the lease term or the estimated useful life of the related asset. Assets acquired under capital leases are amortized on a straight-line basis over (i) the lease term if transfer of ownership does not occur at the end of the lease term or (ii) the estimated useful life of the asset if transfer of ownership does occur at the end of the lease term.
Deferred Charges and Other Assets	Deferred Charges and Other Assets “Deferred charges and other assets, net” primarily include the following: • turnaround costs, which are incurred in connection with planned major maintenance activities at our refineries and ethanol plants and which are deferred when incurred and amortized on a straight-line basis over the period of time estimated to lapse until the next turnaround occurs; • fixed-bed catalyst costs, representing the cost of catalyst that is changed out at periodic intervals when the quality of the catalyst has deteriorated beyond its prescribed function, which are deferred when incurred and amortized on a straight-line basis over the estimated useful life of the specific catalyst; • income taxes receivable; • investments in joint ventures accounted for under the equity method; and • intangible assets.
Impairment of Assets	Impairment of Assets Long-lived assets are tested for recoverability whenever events or changes in circumstances indicate that the carrying amount of the asset may not be recoverable. A long-lived asset is not recoverable if its carrying amount exceeds the sum of the undiscounted cash flows expected to result from its use and eventual disposition. If a long-lived asset is not recoverable, an impairment loss is recognized for the amount by which the carrying amount of the long-lived asset exceeds its fair value, with fair value determined based on discounted estimated net cash flows or other appropriate methods.
Investments	We evaluate our equity method investments for impairment when there is evidence that we may not be able to recover the carrying amount of our investments or the investee is unable to sustain an earnings capacity that justifies the carrying amount. A loss in the value of an investment that is other than a temporary decline is recognized currently in income, and is based on the difference between the estimated current fair value of the investment and its carrying amount.
Environmental Matters	Environmental Matters Liabilities for future remediation costs are recorded when environmental assessments and/or remedial efforts are probable and the costs can be reasonably estimated. Other than for assessments, the timing and magnitude of these accruals generally are based on the completion of investigations or other studies or a commitment to a formal plan of action. Amounts recorded for environmental liabilities have not been reduced by possible recoveries from third parties and have not been measured on a discounted basis.
Asset Retirement Obligations	Asset Retirement Obligations We record a liability, which is referred to as an asset retirement obligation, at fair value for the estimated cost to retire a tangible long-lived asset at the time we incur that liability, which is generally when the asset is purchased, constructed, or leased. We record the liability when we have a legal obligation to incur costs to retire the asset and when a reasonable estimate of the fair value of the liability can be made. If a reasonable estimate cannot be made at the time the liability is incurred, we record the liability when sufficient information is available to estimate the liability’s fair value. We have asset retirement obligations with respect to certain of our refinery assets due to various legal obligations to clean and/or dispose of various component parts of each refinery at the time they are retired. However, these component parts can be used for extended and indeterminate periods of time as long as they are properly maintained and/or upgraded. In addition, we have asset retirement obligations with respect to our ethanol plants and certain of our logistics assets that require us to perform under law or contract once the asset is retired from service. It is our practice and current intent to maintain all our assets and continue making improvements to those assets based on technological advances. As a result, we believe that our refineries, ethanol plants, and logistics assets have indeterminate lives for purposes of estimating asset retirement obligations because dates or ranges of dates upon which we would retire such assets cannot reasonably be estimated at this time. We will recognize a liability at such time when sufficient information exists to estimate a date or range of potential settlement dates that is needed to employ a present value technique to estimate fair value.
Foreign Currency Translation	Foreign Currency Translation The functional currency of each of our international operations is the respective local currency, which includes the Canadian dollar, the pound sterling, the euro, and the Mexican peso. Balance sheet accounts are translated into U.S. dollars using exchange rates in effect as of the balance sheet date. Revenue and expense accounts are translated using the weighted-average exchange rates during the year presented. Foreign currency translation adjustments are recorded as a component of accumulated other comprehensive loss.
Revenue Recognition	Revenue Recognition Revenues for products sold by our refining and ethanol segments are recorded upon delivery and transfer of title to the products to our customers and when payment has either been received or collection is reasonably assured. Our VLP segment generates revenues by providing fee-based transportation and terminaling services to transport and store crude oil and refined petroleum products using its pipelines and terminals under long-term commercial agreements. VLP segment revenues are recognized upon completion of the transportation or terminaling service. However, because VLP segment revenues are intersegment revenues with our refining segment, all VLP segment revenues are eliminated in consolidation. We present excise taxes on sales by certain of our international operations on a gross basis in revenues. The amount of such taxes is provided in supplemental information in a footnote on the statements of income. All other excise taxes are presented on a net basis. We enter into certain purchase and sale arrangements with the same counterparty that are deemed to be made in contemplation of one another. We combine these transactions and present the net effect in cost of materials and other. We also enter into refined petroleum product exchange transactions to fulfill sales contracts with our customers by accessing refined petroleum products in markets where we do not operate our own refineries. These refined petroleum product exchanges are accounted for as exchanges of non-monetary assets, and no revenues are recorded on these transactions.
Cost Classifications	Cost Classifications “Cost of materials and other” primarily includes the cost of materials that are a component of our products sold. These costs include (i) the direct cost of materials (such as crude oil and other refinery feedstocks, refined petroleum products and blendstocks, and ethanol feedstocks and products) that are a component of our products sold; (ii) costs related to the delivery (such as shipping and handling costs) of products sold; (iii) costs related to our environmental credit obligations to comply with various governmental and regulatory programs (such as the cost of Renewable Identification Numbers (RINs) as required by the U.S. Environmental Protection Agency’s (EPA) Renewable Fuel Standard and emission credits under various cap-and-trade systems, as defined in Note 18 ); (iv) gains and losses on our commodity derivative instruments; and (v) certain excise taxes. “Operating expenses (excluding depreciation and amortization expense)” include costs to operate our refineries, ethanol plants, and logistics assets, except for depreciation and amortization expense. These costs primarily include employee-related expenses, energy and utility costs, catalysts and chemical costs, and repair and maintenance expenses. “Depreciation and amortization expense” associated with our operations is separately presented in our statement of income as a component of cost of sales and general and administrative expenses and is disclosed by reportable segment in Note 16 . “Other operating expenses” include costs, if any, incurred by our reportable segments that are not associated with our cost of sales.
Environmental Compliance Program Costs	Environmental Compliance Program Costs We purchase credits in the open market to meet our obligations under various environmental compliance programs. We purchase biofuel credits (primarily RINs in the U.S.) to comply with government regulations that require us to blend a certain percentage of biofuels into the products we produce. To the degree that we are unable to blend biofuels at the required percentage, we must purchase biofuel credits to meet our obligation. We purchase greenhouse gas (GHG) emission credits to comply with government regulations concerning various GHG emission programs, including cap-and-trade systems. These programs are further described in Note 19 under “Environmental Compliance Program Price Risk.” The costs of purchased biofuel credits and GHG emission credits are charged to cost of materials and other as such credits are needed to satisfy our obligation. To the extent we have not purchased enough credits to satisfy our obligation as of the balance sheet date, we charge cost of materials and other for such deficiency based on the market price of the credits as of the balance sheet date, and we record a liability for our obligation to purchase those credits. See Note 18 for disclosure of our fair value liability.
Stock-Based Compensation	Stock-Based Compensation Compensation expense for our share-based compensation plans is based on the fair value of the awards granted and is recognized in income on a straight-line basis over the shorter of (a) the requisite service period of each award or (b) the period from the grant date to the date retirement eligibility is achieved if that date is expected to occur during the vesting period established in the award.
Income Taxes	Income Taxes Income taxes are accounted for under the asset and liability method. Under this 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 amounts are measured using enacted tax rates expected to apply to taxable income in the year those temporary differences are expected to be recovered or settled. Deferred tax assets are reduced by unrecognized tax benefits, if such items may be available to offset the unrecognized tax benefit. We have elected to classify any interest expense and penalties related to the underpayment of income taxes in income tax expense.
Earnings Per Common Share	Earnings per Common Share Earnings per common share is computed by dividing net income attributable to Valero stockholders by the weighted-average number of common shares outstanding for the year. Participating share-based payment awards, including shares of restricted stock granted under certain of our stock-based compensation plans, are included in the computation of basic earnings per share using the two-class method. Earnings per common share – assuming dilution reflects the potential dilution arising from our outstanding stock options and nonvested shares granted to employees in connection with our stock-based compensation plans. Potentially dilutive securities are excluded from the computation of earnings per common share – assuming dilution when the effect of including such shares would be antidilutive.
Financial Instruments	Financial Instruments Our financial instruments include cash and temporary cash investments, receivables, payables, debt, capital lease obligations, commodity derivative contracts, and foreign currency derivative contracts. The estimated fair values of these financial instruments approximate their carrying amounts, except for certain debt as discussed in Note 18 .
Derivatives and Hedging	Derivatives and Hedging All derivative instruments, not designated as normal purchases or sales, are recorded in the balance sheet as either assets or liabilities measured at their fair values with changes in fair value recognized currently in income. To manage commodity price risk, we use economic hedges, which are not designated as fair value or cash flow hedges, and we use fair value and cash flow hedges from time to time. We also enter into certain commodity derivative instruments for trading purposes. The cash flow effects of all of our derivative instruments are reflected in operating activities in the statements of cash flows.
Business Combinations	Business Combinations Effective January 1, 2017, we adopted the provisions of Accounting Standards Update (ASU) No. 2017-01, “Business Combinations (Topic 805),” that was issued by the Financial Accounting Standards Board (FASB) in January 2017. This ASU provides a more robust framework to evaluate whether transactions should be accounted for as acquisitions (dispositions) of assets or businesses. Our adoption of this ASU did not affect our financial position or results of operations. However, more of our future acquisitions may be accounted for as acquisitions of assets in accordance with this ASU.
New Accounting Pronouncements	Accounting Pronouncements Adopted on January 1, 2018 ASU No. 2014-09 In May 2014, the FASB issued ASU No. 2014-09, “Revenue from Contracts with Customers (Topic 606),” to clarify the principles for recognizing revenue. This new standard is effective for annual reporting periods beginning after December 15, 2017, including interim reporting periods within those annual periods. We adopted this standard on January 1, 2018 and it will not materially change the amount or timing of revenues recognized by us, nor will it materially affect our financial position. The majority of our revenues are generated from the sale of refined petroleum products and ethanol. These revenues are largely based on the current spot (market) prices of the products sold, which represent consideration specifically allocable to the products being sold on a given day, and we recognize those revenues upon delivery and transfer of title to the products to our customers. The time at which delivery and transfer of title occurs is the point when our control of the products is transferred to our customers and when our performance obligation to our customers is fulfilled. We adopted this new standard on January 1, 2018 using the modified retrospective method as permitted by the standard. Under this method, the cumulative effect of initially applying the standard is recognized as an adjustment to the opening balance of retained earnings, and revenues reported in the periods prior to the date of adoption are not changed. Because the adoption of this standard did not materially impact the manner in which we recognize revenues, we will not make such an adjustment to retained earnings. We continue to develop our revenue disclosures and have enhanced our accounting systems to enable the preparation of such disclosures. ASU No. 2016-01 In January 2016, the FASB issued ASU No. 2016-01, “Financial Instruments—Overall (Subtopic 825-10),” to enhance the reporting model for financial instruments regarding certain aspects of recognition, measurement, presentation, and disclosure. The provisions of this ASU are effective for annual reporting periods beginning after December 15, 2017, and interim reporting periods within those annual periods. This ASU is to be applied using a cumulative-effect adjustment to the balance sheet as of the beginning of the year of adoption. The adoption of this ASU effective January 1, 2018 did not affect our financial position nor will it affect our results of operations, but it will result in revised disclosures. ASU No. 2017-07 In March 2017, the FASB issued ASU No. 2017-07, “Compensation—Retirement Benefits (Topic 715),” which requires employers to report the service cost component of net periodic pension cost and net periodic postretirement benefit cost in the same line item as other compensation costs arising from services rendered by the pertinent employees during the period. It also requires the other components of net periodic pension cost and net periodic postretirement benefit cost (non-service cost components) to be presented in the income statement separately from the service cost component and outside a subtotal of income from operations. This ASU is to be applied retrospectively for income statement items and prospectively for any capitalized benefit costs. The adoption of this ASU effective January 1, 2018 did not affect our financial position or results of operations, but will result in the reclassification of the non-service cost components from operating expenses (excluding depreciation and amortization) and general and administrative expenses (excluding depreciation and amortization) to “other income, net.” ASU No. 2017-09 In May 2017, the FASB issued ASU No. 2017-09, “Compensation—Stock Compensation (Topic 718),” to reduce diversity in practice, as well as reduce cost and complexity regarding a change to the terms or conditions of a share-based payment award. The adoption of this ASU effective January 1, 2018 did not have an immediate effect on our financial position or results of operations as it will be applied prospectively to an award modified on or after adoption. Accounting Pronouncements Not Yet Adopted ASU No. 2016-02 In February 2016, the FASB issued ASU No. 2016-02, “Leases (Topic 842),” to increase the transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. This new standard is effective for annual reporting periods beginning after December 15, 2018, and interim reporting periods within those annual periods, with early adoption permitted. We will adopt this new standard on January 1, 2019, and we expect to use the modified retrospective method of adoption. We are enhancing our contracting and lease evaluation systems and related processes, and we are developing a new lease accounting system to capture our leases and support the required disclosures. During 2018, we will continue to monitor the adoption process to ensure compliance with accounting and disclosure requirements. We also continue the integration of our lease accounting system with our general ledger, and we will make modifications to the related procurement and payment processes. We anticipate this standard will have a material impact on our financial position by increasing our assets and liabilities by equal amounts through the recognition of right-of-use assets and lease liabilities for our operating leases. However, we do not expect adoption to have a material impact on our results of operations or liquidity. We expect our accounting for capital leases to remain substantially unchanged. ASU No. 2017-12 In August 2017, the FASB issued ASU No. 2017-12, “Derivatives and Hedging (Topic 815),” to improve and simplify accounting guidance for hedge accounting. The provisions of this ASU are effective for annual reporting periods beginning after December 15, 2018, and interim reporting periods within those annual periods, with early adoption permitted. We use economic hedges to manage commodity price risk; however, we have not designated these hedges as fair value or cash flow hedges. As a result, the adoption of this ASU effective January 1, 2019 is not expected to affect our financial position or results of operations. ASU No. 2018-02 In February 2018, the FASB issued ASU No. 2018-02, “Income Statement—Reporting Comprehensive Income (Topic 220),” which allows for the reclassification from accumulated other comprehensive income to retained earnings for the stranded tax effects resulting from the Tax Cuts and Jobs Act of 2017 (Tax Reform), as discussed in Note 14 . The provisions of this ASU are effective for annual reporting periods beginning after December 15, 2018, and interim reporting periods within those annual periods, with early adoption permitted. This ASU shall be applied at the beginning of the annual or interim period of adoption or retrospectively to each period in which the income tax effects of Tax Reform affects the items remaining in accumulated other comprehensive income. The adoption of this ASU is not expected to affect our financial position or results of operations, but will result in the reclassification of the income tax effects of Tax Reform and additional disclosures.
Variable interest entities	We determined VLP is a VIE because the public limited partners of VLP ( i.e. , parties other than entities under common control with the general partner) lack the power to direct the activities of VLP that most significantly impact its economic performance because they do not have substantive kick-out rights over the general partner or substantive participating rights in VLP. Furthermore, we determined that we are the primary beneficiary of VLP because (a) we are the single decision maker and because our general partner interest provides us with the sole power to direct the activities that most significantly impact VLP’s economic performance and (b) our 66.2 percent limited partner interest and 2.0 percent general partner interest provide us with significant economic rights and obligations. We also have financial interests in other entities that have been determined to be VIEs because the entities’ contractual arrangements transfer the power to direct the activities that most significantly impact their economic performance or reduce the exposure to operational variability and risk of loss created by the entity that otherwise would be held exclusively by the equity owners. Furthermore, we determined that we are the primary beneficiary of these VIEs because (a) certain contractual arrangements (exclusive of our ownership rights) provide us with the power to direct the activities that most significantly impact the economic performance of these entities and/or (b) our 50 percent ownership interests provide us with significant economic rights and obligations. In the normal course of business, we have financial interests in certain entities that have been determined to be VIEs. We consolidate a VIE when we have a variable interest in an entity for which we are the primary beneficiary such that we have (a) the power to direct the activities of the VIE that most significantly impact the VIE’s economic performance and (b) the obligation to absorb losses of or the right to receive benefits from the VIE that could potentially be significant to the VIE. In order to make this determination, we evaluated our contractual arrangements with the VIEs, including arrangements for the use of assets, purchases of products and services, debt, equity, or management of operating activities. As operator, we operate the plant and perform certain day-to-day operating and management functions for DGD as an independent contractor. The operations agreement provides us (as operator) and, in the event of certain conditions, the debt agreement provides us (as lender) with certain power to direct the activities that most significantly impact DGD’s economic performance. Because the operations agreement and the debt agreement convey such power to us and are separate from our ownership rights, DGD was determined to be a VIE. For this reason and because we hold a 50 percent ownership interest that provides us with significant economic rights and obligations, we determined that we are the primary beneficiary of DGD.
Offsetting fair value amounts of commodity derivative contracts	We have elected to offset the fair value amounts recognized for multiple similar derivative contracts executed with the same counterparty, including any related cash collateral assets or obligations as shown below; however, fair value amounts by hierarchy level are presented in the following tables on a gross basis. We have no derivative contracts that are subject to master netting arrangements that are reflected gross on the balance sheet.
Derivative instruments collateral requirements	We do not require any collateral or other security to support derivative instruments into which we enter.

Receivables (Tables)

Receivables (Tables)	12 Months Ended
	Dec. 31, 2017
Receivables [Abstract]
Receivables, net	Receivables consisted of the following (in millions): December 31, 2017 2016 Accounts receivable $ 6,786 $ 5,687 Commodity derivative and foreign currency contract receivables 102 129 Other receivables 67 117 6,955 5,933 Allowance for doubtful accounts (33 ) (32 ) Receivables, net $ 6,922 $ 5,901

Inventories (Tables)

Inventories (Tables)	12 Months Ended
	Dec. 31, 2017
Inventory Disclosure [Abstract]
Schedule of inventories	Inventories consisted of the following (in millions): December 31, 2017 2016 Refinery feedstocks $ 2,427 $ 2,068 Refined petroleum products and blendstocks 3,459 3,153 Ethanol feedstocks and products 242 238 Materials and supplies 256 250 Inventories $ 6,384 $ 5,709

Property, Plant, and Equipment

Property, Plant, and Equipment (Tables)	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Major classes of property, plant, and equipment	Major classes of property, plant, and equipment, including assets held under capital leases, consisted of the following (in millions): December 31, 2017 2016 Land $ 411 $ 400 Crude oil processing facilities 30,109 29,754 Transportation and terminaling facilities 4,335 3,692 Grain processing equipment 903 855 Administrative buildings 910 838 Other 2,068 1,464 Construction in progress 1,274 730 Property, plant, and equipment, at cost 40,010 37,733 Accumulated depreciation (12,530 ) (11,261 ) Property, plant, and equipment, net $ 27,480 $ 26,472

Deferred Charges and Other As33

Deferred Charges and Other Assets (Tables)	12 Months Ended
	Dec. 31, 2017
Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract]
Schedule of deferred charges and other assets, net	“Deferred charges and other assets, net” consisted of the following (in millions): December 31, 2017 2016 Deferred turnaround and catalyst costs, net $ 1,520 $ 1,614 Income taxes receivable 673 447 Investments in joint ventures 530 201 Intangible assets, net 142 148 Other 501 491 Deferred charges and other assets, net $ 3,366 $ 2,901

Accrued Expenses and Other Lo34

Accrued Expenses and Other Long-Term Liabilities (Tables)	12 Months Ended
	Dec. 31, 2017
Accrued Expenses and Other Long-Term Liabilities [Abstract]
Accrued expenses and other long-term liabilities	Accrued expenses and other long-term liabilities consisted of the following (in millions): Accrued Expenses Other Long- Term Liabilities December 31, December 31, 2017 2016 2017 2016 Defined benefit plan liabilities (see Note 12) $ 33 $ 32 $ 776 $ 742 Wage and other employee-related liabilities 278 225 111 103 Uncertain income tax position liabilities (see Note 14) — — 723 465 Repatriation tax liability (see Note 14) — — 597 — Environmental liabilities 30 29 232 223 Environmental credit obligations (see Note 18) 152 214 — — Accrued interest expense 105 104 — — Other accrued liabilities 114 90 290 211 Accrued expenses and other long-term liabilities $ 712 $ 694 $ 2,729 $ 1,744

Debt and Capital Lease Obliga35

Debt and Capital Lease Obligations (Tables)	12 Months Ended
	Dec. 31, 2017
Debt and Capital Lease Obligations [Abstract]
Debt and capital lease obligations	Debt, at stated values, and capital lease obligations consisted of the following (in millions): Final Maturity December 31, 2017 2016 Bank credit facilities: Valero Revolver 2020 $ — $ — VLP Revolver 2020 410 30 Canadian Revolver 2018 — — Accounts receivable sales facility 2018 100 100 Non-bank debt: Valero Senior Notes 6.625% 2037 1,500 1,500 3.4% 2026 1,250 1,250 6.125% 2020 850 850 9.375% 2019 750 750 7.5% 2032 750 750 4.9% 2045 650 650 3.65% 2025 600 600 10.5% 2039 250 250 8.75% 2030 200 200 7.45% 2097 100 100 6.75% 2037 24 24 VLP Senior Notes, 4.375% 2026 500 500 Gulf Opportunity Zone Revenue Bonds, Series 2010, 4.0% 2040 300 300 Debenture, 7.65% 2026 100 100 Other debt 2023 49 51 Net unamortized debt issuance costs and other (73 ) (79 ) Total debt 8,310 7,926 Capital lease obligations 562 75 Total debt and capital lease obligations 8,872 8,001 Less current portion 122 115 Debt and capital lease obligations, less current portion $ 8,750 $ 7,886
Summary of credit facilities	Summary of Credit Facilities We had outstanding borrowings, letters of credit issued, and availability under our credit facilities as follows (in millions): December 31, 2017 Facility Amount Maturity Date Outstanding Borrowings Letters of Credit Issued Availability Committed facilities: Valero Revolver $ 3,000 November 2020 $ — $ 54 $ 2,946 VLP Revolver $ 750 November 2020 $ 410 $ — $ 340 Canadian Revolver C$ 75 November 2018 C$ — C$ 10 C$ 65 Accounts receivable sales facility $ 1,300 July 2018 $ 100 n/a $ 1,200 Letter of credit facility $ 100 November 2018 n/a $ — $ 100 Uncommitted facilities: Letter of credit facilities n/a n/a n/a $ 249 n/a
Interest and debt expense, net of capitalized interest	Interest and debt expense, net of capitalized interest is comprised as follows (in millions): Year Ended December 31, 2017 2016 2015 Interest and debt expense $ 539 $ 511 $ 504 Less capitalized interest 71 65 71 Interest and debt expense, net of capitalized interest $ 468 $ 446 $ 433
Principal payments on debt and future minimum rentals on capital lease obligations	Principal maturities for our debt obligations and future minimum rentals on capital lease obligations as of December 31, 2017 were as follows (in millions): Debt Capital Lease Obligations 2018 $ 106 $ 55 2019 756 55 2020 1,266 53 2021 6 52 2022 6 54 Thereafter 6,243 969 Net unamortized debt issuance costs and other (73 ) n/a Total minimum lease payments n/a 1,238 Less amount representing interest n/a 676 Total $ 8,310 $ 562

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Future minimum rentals for leases having initial or remaining noncancelable lease terms in excess of one year	As of December 31, 2017 , our future minimum rentals for leases having initial or remaining noncancelable lease terms in excess of one year were as follows (in millions): 2018 $ 359 2019 236 2020 148 2021 104 2022 74 Thereafter 366 Total minimum rental payments $ 1,287 Minimum rentals to be received under subleases $ 15
Rental expense for all operating leases	Rental expense, net of sublease rental income” was as follows (in millions): Year Ended December 31, 2017 2016 2015 Minimum rental expense $ 691 $ 739 $ 732 Contingent rental expense 21 70 105 Total rental expense 712 809 837 Less sublease rental income 54 31 46 Rental expense, net of sublease rental income $ 658 $ 778 $ 791

Equity (Tables)

Equity (Tables)	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Share activity	Activity in the number of shares of common stock and treasury stock was as follows (in millions): Common Stock Treasury Stock Balance as of December 31, 2014 673 (159 ) Transactions in connection with stock-based compensation plans — 1 Stock purchases under purchase program — (42 ) Balance as of December 31, 2015 673 (200 ) Transactions in connection with stock-based compensation plans — 1 Stock purchases under purchase program — (23 ) Balance as of December 31, 2016 673 (222 ) Transactions in connection with stock-based compensation plans — 1 Stock purchases under purchase program — (19 ) Balance as of December 31, 2017 673 (240 )
Income tax effects related to components of other comprehensive income (loss)	The tax effects allocated to each component of other comprehensive income (loss) were as follows (in millions): Before-Tax Amount Tax Expense (Benefit) Net Amount Year Ended December 31, 2017: Foreign currency translation adjustment $ 514 $ — $ 514 Pension and other postretirement benefits: Loss arising during the year related to: Net actuarial loss (79 ) (29 ) (50 ) Prior service cost (4 ) (1 ) (3 ) Miscellaneous loss — 3 (3 ) Amounts reclassified into income related to: Net actuarial loss 50 18 32 Prior service credit (36 ) (13 ) (23 ) Curtailment and settlement loss 4 1 3 Net loss on pension and other postretirement benefits (65 ) (21 ) (44 ) Other comprehensive income $ 449 $ (21 ) $ 470 Before-Tax Amount Tax Expense (Benefit) Net Amount Year Ended December 31, 2016: Foreign currency translation adjustment $ (415 ) $ — $ (415 ) Pension and other postretirement benefits: Gain (loss) arising during the year related to: Net actuarial loss (110 ) (34 ) (76 ) Miscellaneous gain — (8 ) 8 Amounts reclassified into income related to: Net actuarial loss 48 18 30 Prior service credit (36 ) (13 ) (23 ) Net loss on pension and other postretirement benefits (98 ) (37 ) (61 ) Other comprehensive loss $ (513 ) $ (37 ) $ (476 ) Year Ended December 31, 2015: Foreign currency translation adjustment $ (606 ) $ — $ (606 ) Pension and other postretirement benefits: Gain (loss) arising during the year related to: Net actuarial gain 50 15 35 Prior service cost (22 ) (8 ) (14 ) Amounts reclassified into income related to: Net actuarial loss 62 22 40 Prior service credit (40 ) (14 ) (26 ) Curtailment and settlement loss 7 2 5 Net gain on pension and other postretirement benefits 57 17 40 Other comprehensive loss $ (549 ) $ 17 $ (566 )
Changes in components of accumulated other comprehensive income (loss)	Changes in accumulated other comprehensive income (loss) by component, net of tax, were as follows (in millions): Foreign Currency Translation Adjustment Defined Benefit Plan Items Total Balance as of December 31, 2014 $ 1 $ (368 ) $ (367 ) Other comprehensive income (loss) before reclassifications (606 ) 21 (585 ) Amounts reclassified from accumulated other comprehensive income (loss) — 19 19 Net other comprehensive income (loss) (606 ) 40 (566 ) Balance as of December 31, 2015 (605 ) (328 ) (933 ) Other comprehensive loss before reclassifications (416 ) (68 ) (484 ) Amounts reclassified from accumulated other comprehensive loss — 7 7 Net other comprehensive loss (416 ) (61 ) (477 ) Balance as of December 31, 2016 (1,021 ) (389 ) (1,410 ) Other comprehensive income (loss) before reclassifications 514 (56 ) 458 Amounts reclassified from accumulated other comprehensive loss — 12 12 Net other comprehensive income (loss) 514 (44 ) 470 Balance as of December 31, 2017 $ (507 ) $ (433 ) $ (940 )
Gains (losses) reclassified out of accumulated other comprehensive income (loss)	Gains (losses) reclassified out of accumulated other comprehensive loss and into net income were as follows (in millions): Details about Accumulated Other Comprehensive Loss Components Affected Line Item in the Statement of Income Year Ended December 31, 2017 2016 2015 Amortization of items related to defined benefit pension plans: Net actuarial loss $ (50 ) $ (48 ) $ (62 ) (a) Prior service credit 36 36 40 (a) Curtailment and settlement (4 ) — (7 ) (a) (18 ) (12 ) (29 ) Total before tax 6 5 10 Tax benefit Total reclassifications for the year $ (12 ) $ (7 ) $ (19 ) Net of tax _________________________ (a) These accumulated other comprehensive loss components are included in the computation of net periodic benefit cost, as further discussed in Note 12 . Net periodic benefit cost is reflected in operating expenses (excluding depreciation and amortization expense) and general and administrative expenses (excluding depreciation and amortization expense).

Variable Interest Entities (Tab

Variable Interest Entities (Tables)	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Summarized balance sheet information of VIEs	The following tables present summarized balance sheet information for the significant assets and liabilities of our VIEs, which are included in our balance sheets (in millions). December 31, 2017 VLP DGD VPM Terminals Other Total Assets Cash and temporary cash investments $ 42 $ 123 $ 1 $ 13 $ 179 Other current assets 2 66 4 — 72 Property, plant, and equipment, net 1,416 435 51 127 2,029 Liabilities Current liabilities $ 27 $ 33 $ 26 $ 9 $ 95 Debt and capital lease obligations, less current portion 905 — — 43 948 December 31, 2016 VLP DGD Other Total Assets Cash and temporary cash investments $ 71 $ 167 $ 15 $ 253 Other current assets 3 87 — 90 Property, plant, and equipment, net 865 355 133 1,353 Liabilities Current liabilities $ 15 $ 17 $ 7 $ 39 Debt and capital lease obligations, less current portion 525 — 46 571

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	12 Months Ended
	Dec. 31, 2017
Retirement Benefits [Abstract]
The changes in benefit obligation, the changes in fair value of plan assets, and the funded status of our pension plans and other postretirement benefit plans	The changes in benefit obligation related to all of our defined benefit plans, the changes in fair value of plan assets (a) , and the funded status of our defined benefit plans as of and for the years ended were as follows (in millions): Pension Plans Other Postretirement Benefit Plans December 31, December 31, 2017 2016 2017 2016 Changes in benefit obligation: Benefit obligation as of beginning of year $ 2,567 $ 2,365 $ 302 $ 336 Service cost 123 111 6 7 Interest cost 86 84 10 12 Participant contributions — — 9 8 Benefits paid (158 ) (130 ) (28 ) (27 ) Actuarial (gain) loss 286 171 6 (35 ) Other 22 (34 ) 1 1 Benefit obligation as of end of year $ 2,926 $ 2,567 $ 306 $ 302 Changes in plan assets (a): Fair value of plan assets as of beginning of year $ 2,097 $ 1,947 $ — $ — Actual return on plan assets 363 165 — — Valero contributions 110 141 19 18 Participant contributions — — 9 8 Benefits paid (158 ) (130 ) (28 ) (27 ) Other 16 (26 ) — 1 Fair value of plan assets as of end of year $ 2,428 $ 2,097 $ — $ — Reconciliation of funded status (a) : Fair value of plan assets as of end of year $ 2,428 $ 2,097 $ — $ — Less benefit obligation as of end of year 2,926 2,567 306 302 Funded status as of end of year $ (498 ) $ (470 ) $ (306 ) $ (302 ) Accumulated benefit obligation $ 2,746 $ 2,419 n/a n/a ___________________________ (a) Plan assets include only the assets associated with pension plans subject to legal minimum funding standards. Plan assets associated with U.S. nonqualified pension plans are not included here because they are not protected from our creditors and therefore cannot be reflected as a reduction from our obligations under the pension plans. As a result, the reconciliation of funded status does not reflect the effect of plan assets that exist for all of our defined benefit plans. See Note 18 for the assets associated with certain U.S. nonqualified pension plans.
Schedule of amounts recognized in balance sheet	Amounts recognized in our balance sheet for our pension and other postretirement benefits plans include (in millions): Pension Plans Other Postretirement Benefit Plans December 31, December 31, 2017 2016 2017 2016 Deferred charges and other assets, net $ 5 $ 2 $ — $ — Accrued expenses (14 ) (13 ) (19 ) (19 ) Other long-term liabilities (489 ) (459 ) (287 ) (283 ) $ (498 ) $ (470 ) $ (306 ) $ (302 )
Benefit obligations in excess of fair value of plan assets	The accumulated benefit obligations for certain of our pension plans exceed the fair values of the assets of those plans. For those plans, the following table presents the total projected benefit obligation, accumulated benefit obligation, and fair value of the plan assets (in millions). December 31, 2017 2016 Projected benefit obligation $ 2,661 $ 2,322 Accumulated benefit obligation 2,526 2,210 Fair value of plan assets 2,180 1,870
Expected benefit payments	Benefit payments that we expect to pay, including amounts related to expected future services that we expect to receive, are as follows for the years ending December 31 (in millions): Pension Benefits Other Postretirement Benefits 2018 $ 162 $ 19 2019 219 19 2020 184 19 2021 180 19 2022 185 19 2023-2027 1,074 93
Components of net periodic benefit costs	The components of net periodic benefit cost (credit) related to our defined benefit plans were as follows (in millions): Pension Plans Other Postretirement Benefit Plans Year Ended December 31, Year Ended December 31, 2017 2016 2015 2017 2016 2015 Service cost $ 123 $ 111 $ 109 $ 6 $ 7 $ 8 Interest cost 86 84 98 10 12 14 Expected return on plan assets (150 ) (139 ) (133 ) — — — Amortization of: Net actuarial (gain) loss 53 49 62 (3 ) (1 ) — Prior service credit (20 ) (20 ) (22 ) (16 ) (16 ) (18 ) Special charges (credits) 4 (7 ) 7 — — — Net periodic benefit cost (credit) $ 96 $ 78 $ 121 $ (3 ) $ 2 $ 4
Pre-tax amounts recognized in other comprehensive income	Pre-tax amounts recognized in other comprehensive income (loss) were as follows (in millions): Pension Plans Other Postretirement Benefit Plans Year Ended December 31, Year Ended December 31, 2017 2016 2015 2017 2016 2015 Net gain (loss) arising during the year: Net actuarial gain (loss) $ (73 ) $ (145 ) $ 24 $ (6 ) $ 35 $ 26 Prior service cost (4 ) — (22 ) — — — Net (gain) loss reclassified into income: Net actuarial (gain) loss 53 49 62 (3 ) (1 ) — Prior service credit (20 ) (20 ) (22 ) (16 ) (16 ) (18 ) Curtailment and settlement loss 4 — 7 — — — Total changes in other comprehensive income (loss) $ (40 ) $ (116 ) $ 49 $ (25 ) $ 18 $ 8
Pre-tax amounts in accumulated other comprehensive income not yet recognized	The pre-tax amounts in accumulated other comprehensive loss that have not yet been recognized as components of net periodic benefit cost (credit) were as follows (in millions): Pension Plans Other Postretirement Benefit Plans December 31, December 31, 2017 2016 2017 2016 Net actuarial (gain) loss $ 894 $ 878 $ (57 ) $ (66 ) Prior service credit (121 ) (145 ) (42 ) (58 ) Total $ 773 $ 733 $ (99 ) $ (124 )
Pre-tax amounts in accumulated other comprehensive income to be recognized in the next fiscal year	The following pre-tax amounts included in accumulated other comprehensive loss as of December 31, 2017 are expected to be recognized as components of net periodic benefit cost (credit) during the year ending December 31, 2018 (in millions): Pension Plans Other Postretirement Benefit Plans Amortization of net actuarial (gain) loss $ 66 $ (2 ) Amortization of prior service credit (19 ) (11 ) Total $ 47 $ (13 )
Weighted-average assumptions used to determine the benefit obligations and net periodic benefit cost	The weighted-average assumptions used to determine the benefit obligations were as follows: Pension Plans Other Postretirement Benefit Plans December 31, December 31, 2017 2016 2017 2016 Discount rate 3.58 % 4.08 % 3.72 % 4.26 % Rate of compensation increase 3.86 % 3.81 % n/a n/a The weighted-average assumptions used to determine the net periodic benefit cost were as follows: Pension Plans Other Postretirement Benefit Plans Year Ended December 31, Year Ended December 31, 2017 2016 2015 2017 2016 2015 Discount rate 4.08 % 4.45 % 4.10 % 4.26 % 4.53 % 4.13 % Expected long-term rate of return on plan assets 7.29 % 7.28 % 7.29 % n/a n/a n/a Rate of compensation increase 3.81 % 3.79 % 3.78 % n/a n/a n/a
Assumed health care cost trend rates	The assumed health care cost trend rates were as follows: December 31, 2017 2016 Health care cost trend rate assumed for the next year 7.30 % 7.28 % Rate to which the cost trend rate was assumed to decline (the ultimate trend rate) 5.00 % 5.00 % Year that the rate reaches the ultimate trend rate 2026 2026
Fair value of pension plan assets by level of fair value hierarchy	The following tables present the fair values of the assets of our pension plans (in millions) as of December 31, 2017 and 2016 by level of the fair value hierarchy. Assets categorized in Level 1 of the hierarchy are measured at fair value using a market approach based on quotations from national securities exchanges. Assets categorized in Level 2 of the hierarchy are measured at net asset value in a market that is not active. As previously noted, we do not fund or fully fund U.S. nonqualified and certain international pension plans that are not subject to funding requirements, and we do not fund our other postretirement benefit plans. Fair Value Measurements Using Total as of Level 1 Level 2 Level 3 Equity securities: U.S. companies (a) $ 571 $ — $ — $ 571 International companies 187 1 — 188 Preferred stock 4 — — 4 Mutual funds: International growth 118 — — 118 Index funds (b) 85 — — 85 Corporate debt instruments — 272 — 272 Government securities: U.S. Treasury securities 45 — — 45 Other government securities — 144 — 144 Common collective trusts (c) — 621 — 621 Pooled separate accounts — 192 — 192 Private funds — 101 — 101 Insurance contract — 18 — 18 Interest and dividends receivable 5 — — 5 Cash and cash equivalents 85 1 — 86 Securities transactions payable, net (22 ) — — (22 ) Total pension assets $ 1,078 $ 1,350 $ — $ 2,428 ___________________________ See notes on page 109 . Fair Value Measurements Using Total as of Level 1 Level 2 Level 3 Equity securities: U.S. companies (a) $ 562 $ — $ — $ 562 International companies 164 — — 164 Preferred stock 3 — — 3 Mutual funds: International growth 90 — — 90 Index funds (b) 230 — — 230 Corporate debt instruments — 280 — 280 Government securities: U.S. Treasury securities 52 — — 52 Other government securities — 158 — 158 Common collective trusts (c) — 434 — 434 Private funds — 76 — 76 Insurance contract — 18 — 18 Interest and dividends receivable 5 — — 5 Cash and cash equivalents 56 16 — 72 Securities transactions payable, net (47 ) — — (47 ) Total pension assets $ 1,115 $ 982 $ — $ 2,097 __________________________________ (a) Equity securities are held in a wide range of industrial sectors, including consumer goods, information technology, healthcare, industrials, and financial services. (b) This class includes primarily investments in approximately 70 percent equities and 30 percent bonds as of December 31, 2017 . As of December 31, 2016 , the class included primarily investments in approximately 50 percent equities and 50 percent bonds. (c) This class includes primarily investments in approximately 80 percent equities and 20 percent bonds as of December 31, 2017 . As of December 31, 2016 , the class included primarily investments in approximately 90 percent equities and 10 percent bonds.

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of stock-based compensation expense and tax benefits	The following table reflects activity related to our stock-based compensation arrangements (in millions): Year Ended December 31, 2017 2016 2015 Stock-based compensation expense: Restricted stock $ 58 $ 52 $ 47 Performance awards 19 15 11 Stock options — 1 1 Total stock-based compensation expense $ 77 $ 68 $ 59 Tax benefit recognized on stock-based compensation expense $ 27 $ 24 $ 21 Tax benefit realized for tax deductions resulting from exercises and vestings 44 33 66 Effect of tax deductions in excess of recognized stock-based compensation expense (a) 24 22 44 _______________________________ (a) Effective January 1, 2016, the effect of tax deductions in excess of recognized stock-based compensation expense is reported as an operating cash flow. These amounts were previously reported as financing cash flows.
Summary of restricted stock awards	The following table reflects activity related to our restricted stock (in millions, except per share data): Year Ended December 31, 2017 2016 2015 Weighted-average grant-date fair value per share of restricted stock granted $ 79.32 $ 59.00 $ 70.07 Fair value of restricted stock vested 71 46 69 The fair value of each restricted stock per share is equal to the market price of our common stock. A summary of the status of our restricted stock awards is presented in the following table. Number of Shares Weighted- Average Grant-Date Fair Value Per Share Nonvested shares as of January 1, 2017 1,566,950 $ 60.68 Granted 739,393 79.32 Vested (897,246 ) 61.76 Forfeited (8,057 ) 61.22 Nonvested shares as of December 31, 2017 1,401,040 69.82

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income from continuing operations before income tax expense from U.S. and international operations	Income before income tax expense (benefit) was as follows (in millions): Year Ended December 31, 2017 2016 2015 U.S. operations $ 2,283 $ 1,733 $ 5,327 International operations 924 1,449 644 Income before income tax expense (benefit) $ 3,207 $ 3,182 $ 5,971
Reconciliation of income tax expense related to continuing operations to income tax expense at statutory rate	Statutory income tax rates applicable to the countries in which we operate were as follows: Year Ended December 31, 2017 2016 2015 U.S. (a) 35 % 35 % 35 % Canada 15 % 15 % 15 % U.K. 19 % 20 % 20 % Ireland 13 % 13 % 13 % Aruba (b) n/a 7 % 7 % ___________________________ (a) Statutory income tax rate was reduced to 21 percent effective January 1, 2018 as described in “Tax Reform” above. (b) Statutory income tax rate applicable through the date of the Aruba Disposition as described in Note 2 . The following is a reconciliation of income tax expense (benefit) computed by applying statutory income tax rates as reflected in the preceding table to actual income tax expense (benefit) related to our operations (in millions): Year Ended December 31, 2017 U.S. International Total Amount Percent Amount Percent Amount Percent Income tax expense at statutory rates $ 799 35.0 % $ 158 17.1 % $ 957 29.8 % U.S. state and Canadian provincial tax expense, net of federal income tax effect 37 1.6 % 46 5.0 % 83 2.6 % Permanent differences: Manufacturing deduction (42 ) (1.8 )% — — (42 ) (1.3 )% Other (9 ) (0.4 )% — — (9 ) (0.3 )% Change in tax law (1,862 ) (81.6 )% — — (1,862 ) (58.1 )% Tax effects of income associated with noncontrolling interests (31 ) (1.4 )% — — (31 ) (1.0 )% Other, net (52 ) (2.3 )% 7 0.8 % (45 ) (1.4 )% Income tax expense (benefit) $ (1,160 ) (50.9 )% $ 211 22.9 % $ (949 ) (29.7 )% Year Ended December 31, 2016 U.S. International Total Amount Percent Amount Percent Amount Percent Income tax expense at statutory rates $ 606 35.0 % $ 256 17.7 % $ 862 27.1 % U.S. state and Canadian provincial tax expense, net of federal income tax effect 5 0.3 % 31 2.1 % 36 1.1 % Permanent differences: Manufacturing deduction (22 ) (1.3 )% — — (22 ) (0.7 )% Other (3 ) (0.2 )% (10 ) (0.7 )% (13 ) (0.4 )% Change in tax law — — (7 ) (0.5 )% (7 ) (0.2 )% Tax effects of income associated with noncontrolling interests (44 ) (2.5 )% — — (44 ) (1.4 )% Other, net (37 ) (2.1 )% (10 ) (0.7 )% (47 ) (1.5 )% Income tax expense $ 505 29.2 % $ 260 17.9 % $ 765 24.0 % Year Ended December 31, 2015 U.S. International Total Amount Percent Amount Percent Amount Percent Income tax expense at statutory rates $ 1,864 35.0 % $ 92 14.3 % $ 1,956 32.8 % U.S. state and Canadian provincial tax expense, net of federal income tax effect 45 0.8 % 73 11.3 % 118 2.0 % Permanent differences: Manufacturing deduction (102 ) (1.9 )% — — (102 ) (1.7 )% Other (18 ) (0.3 )% (5 ) (0.8 )% (23 ) (0.4 )% Change in tax law — — (17 ) (2.6 )% (17 ) (0.3 )% Tax effects of income associated with noncontrolling interests (39 ) (0.7 )% — — (39 ) (0.7 )% Other, net (25 ) (0.5 )% 2 0.3 % (23 ) (0.4 )% Income tax expense $ 1,725 32.4 % $ 145 22.5 % $ 1,870 31.3 %
Components of income tax expense related to continuing operations	The following table details the components of our adjustment (in millions) to reflect the effects of Tax Reform for the year ended December 31, 2017 , including (i) whether such amounts are complete, provisional, or incomplete, and (ii) the additional information that we need to obtain in order to complete the accounting as required by SAB 118. See “Tax Reform” above for a discussion of the provisions of SAB 118. Accounting Status Amount Income tax benefit from the remeasurement of U.S. deferred income tax assets and liabilities Complete $ (2,643 ) Tax on the deemed repatriation of the accumulated earnings and profits of our international subsidiaries Provisional 734 Recognition of foreign withholding tax, net of U.S. federal tax benefit Complete 47 Deductibility of certain executive compensation expense Incomplete — Income tax expense associated with the statutory income tax rate differential on accrual to return adjustments that may be identified upon completion of our U.S. federal income tax return in 2018 Incomplete — Foreign tax credit available to offset the tax on deemed repatriation of the accumulated earnings and profits of our international subsidiaries Incomplete — Estimated Tax Reform benefit $ (1,862 ) Components of income tax expense (benefit) related to our operations were as follows (in millions): Year Ended December 31, 2017 U.S. International Total Current: Country $ 1,305 $ 194 $ 1,499 U.S. state / Canadian provincial 34 61 95 Total current 1,339 (a) 255 1,594 Deferred: Country (2,522 ) (29 ) (2,551 ) U.S. state / Canadian provincial 23 (15 ) 8 Total deferred (2,499 ) (b) (44 ) (2,543 ) Income tax expense (benefit) $ (1,160 ) $ 211 $ (949 ) ___________________________ See notes on page 116 . Year Ended December 31, 2016 U.S. International Total Current: Country $ 294 $ 194 $ 488 U.S. state / Canadian provincial 12 35 47 Total current 306 229 535 Deferred: Country 203 35 238 U.S. state / Canadian provincial (4 ) (4 ) (8 ) Total deferred 199 31 230 Income tax expense $ 505 $ 260 $ 765 Year Ended December 31, 2015 U.S. International Total Current: Country $ 1,513 $ 64 $ 1,577 U.S. state / Canadian provincial 85 43 128 Total current 1,598 107 1,705 Deferred: Country 143 8 151 U.S. state / Canadian provincial (16 ) 30 14 Total deferred 127 38 165 Income tax expense $ 1,725 $ 145 $ 1,870 ___________________________ (a) Current income tax expense includes the effect of our $781 million Tax Reform adjustment as described in “Tax Reform” above. (b) Deferred income tax benefit includes the effect of our $2.6 billion Tax Reform adjustment as described in “Tax Reform” above.
Schedule of income taxes paid, net	Income taxes paid to U.S. and international taxing authorities were as follows (in millions): Year Ended December 31, 2017 2016 2015 U.S. $ 239 $ 241 $ 2,092 International 171 203 1 Income taxes paid, net $ 410 $ 444 $ 2,093
Deferred income tax assets and liabilities	The tax effects of significant temporary differences representing deferred income tax assets and liabilities were as follows (in millions): December 31, 2017 2016 Deferred income tax assets: Tax credit carryforwards $ 69 $ 65 Net operating losses (NOLs) 492 374 Inventories 135 93 Compensation and employee benefit liabilities 179 344 Environmental liabilities 47 69 Other 112 100 Total deferred income tax assets 1,034 1,045 Valuation allowance (498 ) (374 ) Net deferred income tax assets 536 671 Deferred income tax liabilities: Property, plant, and equipment 4,545 6,900 Deferred turnaround costs 272 450 Inventories 243 356 Investments 77 253 Other 107 73 Total deferred income tax liabilities 5,244 8,032 Net deferred income tax liabilities $ 4,708 $ 7,361
Income tax credit and loss carryforwards	We had the following income tax credit and loss carryforwards as of December 31, 2017 (in millions): Amount Expiration U.S. state income tax credits $ 76 2018 through 2031 U.S. state income tax credits 11 Unlimited U.S. state NOLs (gross amount) 9,441 2018 through 2037
Reconciliation of the change in unrecognized tax benefits	The following is a reconciliation of the change in unrecognized tax benefits, excluding related penalties and interest, (in millions): Year Ended December 31, 2017 2016 2015 Balance as of beginning of year $ 936 $ 964 $ 989 Additions based on tax positions related to the current year 33 36 36 Additions for tax positions related to prior years 15 11 83 Reductions for tax positions related to prior years (42 ) (46 ) (82 ) Reductions for tax positions related to the lapse of applicable statute of limitations (1 ) (3 ) (3 ) Settlements — (237 ) (59 ) Reclassification of uncertain tax receivable to long-term receivable from IRS — 211 — Balance as of end of year $ 941 $ 936 $ 964
Summary of income tax contingencies	The following is a reconciliation of unrecognized tax benefits reflected in the preceding table to our uncertain tax position liabilities that are presented in our balance sheets (in millions). December 31, 2017 2016 Unrecognized tax benefits $ 941 $ 936 Tax refund claim not presented in our balance sheets (274 ) (433 ) Other 77 (5 ) Uncertain tax position liabilities presented in our balance sheets $ 744 $ 498 Amounts recognized in our balance sheets for uncertain tax positions include (in millions): December 31, 2017 2016 Income taxes payable $ — $ (7 ) Other long-term liabilities (723 ) (465 ) Deferred tax liabilities (21 ) (26 ) Uncertain tax position liabilities presented in our balance sheets $ (744 ) $ (498 )

Earnings Per Common Share (Tabl

Earnings Per Common Share (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Schedule of earnings per common share, basic and diluted	Earnings per common share were computed as follows (dollars and shares in millions, except per share amounts): Year Ended December 31, 2017 2016 2015 Participating Common Stock Participating Common Stock Participating Common Stock Earnings per common share: Net income attributable to Valero stockholders $ 4,065 $ 2,289 $ 3,990 Less dividends paid: Common stock 1,238 1,108 845 Participating securities 4 3 3 Undistributed earnings $ 2,823 $ 1,178 $ 3,142 Weighted-average common shares outstanding 2 442 1 461 2 497 Earnings per common share: Distributed earnings $ 2.80 $ 2.80 $ 2.40 $ 2.40 $ 1.70 $ 1.70 Undistributed earnings 6.37 6.37 2.54 2.54 6.30 6.30 Total earnings per common share $ 9.17 $ 9.17 $ 4.94 $ 4.94 $ 8.00 $ 8.00 Earnings per common share – assuming dilution: Net income attributable to Valero stockholders $ 4,065 $ 2,289 $ 3,990 Weighted-average common shares outstanding 442 461 497 Common equivalent shares 2 3 3 Weighted-average common shares outstanding – assuming dilution 444 464 500 Earnings per common share – assuming dilution $ 9.16 $ 4.94 $ 7.99

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Segment activity, including total assets by reportable segment	The following table reflects activity related to our reportable segments (in millions): Refining Ethanol VLP Corporate and Eliminations Total Year ended December 31, 2017: Operating revenues: Operating revenues from external customers $ 90,651 $ 3,324 $ — $ 5 $ 93,980 Intersegment revenues 6 176 452 (634 ) — Total operating revenues 90,657 3,500 452 (629 ) 93,980 Cost of sales: Cost of materials and other 80,865 2,804 — (632 ) 83,037 Operating expenses (excluding depreciation and amortization expense reflected below) 3,917 443 104 (2 ) 4,462 Depreciation and amortization expense 1,800 81 53 — 1,934 Total cost of sales 86,582 3,328 157 (634 ) 89,433 Other operating expenses 58 — 3 — 61 General and administrative expenses (excluding depreciation and amortization expense reflected below) — — — 835 835 Depreciation and amortization expense — — — 52 52 Operating income by segment $ 4,017 $ 172 $ 292 $ (882 ) $ 3,599 Total expenditures for long-lived assets $ 1,710 $ 84 $ 110 $ 44 $ 1,948 Year ended December 31, 2016: Operating revenues: Operating revenues from external customers $ 71,968 $ 3,691 $ — $ — $ 75,659 Intersegment revenues — 210 363 (573 ) — Total operating revenues 71,968 3,901 363 (573 ) 75,659 Cost of sales: Cost of materials and other 63,405 3,130 — (573 ) 65,962 Operating expenses (excluding depreciation and amortization expense reflected below) 3,696 415 96 — 4,207 Depreciation and amortization expense 1,734 66 46 — 1,846 Lower of cost or market inventory valuation adjustment (697 ) (50 ) — — (747 ) Total cost of sales 68,138 3,561 142 (573 ) 71,268 General and administrative expenses (excluding depreciation and amortization expense reflected below) — — — 715 715 Depreciation and amortization expense — — — 48 48 Asset impairment loss 56 — — — 56 Operating income by segment $ 3,774 $ 340 $ 221 $ (763 ) $ 3,572 Total expenditures for long-lived assets $ 1,867 $ 68 $ 23 $ 38 $ 1,996 Refining Ethanol VLP Corporate and Eliminations Total Year Ended December 31, 2015: Operating revenues: Operating revenues from external customers $ 84,521 $ 3,283 $ — $ — $ 87,804 Intersegment revenues — 151 244 (395 ) — Total operating revenues 84,521 3,434 244 (395 ) 87,804 Cost of sales: Cost of materials and other 71,512 2,744 — (395 ) 73,861 Operating expenses (excluding depreciation and amortization expense reflected below) 3,689 448 106 — 4,243 Depreciation and amortization expense 1,699 50 46 — 1,795 Lower of cost or market inventory valuation adjustment 740 50 — — 790 Total cost of sales 77,640 3,292 152 (395 ) 80,689 General and administrative expenses (excluding depreciation and amortization expense reflected below) — — — 710 710 Depreciation and amortization expense — — — 47 47 Operating income by segment $ 6,881 $ 142 $ 92 $ (757 ) $ 6,358 Total expenditures for long-lived assets $ 2,216 $ 67 $ 38 $ 29 $ 2,350 Total assets by reportable segment were as follows (in millions): December 31, 2017 2016 Refining $ 40,382 $ 38,095 Ethanol 1,344 1,316 VLP 1,517 979 Corporate and eliminations 6,915 5,783 Total assets $ 50,158 $ 46,173
Operating revenues from external customers by product	Operating revenues from external customers by reportable segment for our principal products were as follows (in millions): Year Ended December 31, 2017 2016 2015 Refining: Gasolines and blendstocks $ 40,362 $ 33,450 $ 38,983 Distillates 42,074 32,576 38,093 Other product revenues 8,215 5,942 7,445 Total refining revenues 90,651 71,968 84,521 Ethanol: Ethanol 2,764 3,105 2,628 Distillers grains 560 586 655 Total ethanol revenues 3,324 3,691 3,283 Corporate – other revenues 5 — — Total revenues from external customers $ 93,980 $ 75,659 $ 87,804
Operating revenues by geographic area of customer	Operating revenues by geographic area are shown in the following table (in millions). The geographic area is based on location of customer and no customer accounted for 10 percent or more of our operating revenues. Year Ended December 31, 2017 2016 2015 U.S. $ 66,614 $ 51,479 $ 60,319 Canada 7,039 6,115 6,841 U.K. and Ireland 11,556 10,797 11,232 Other countries 8,771 7,268 9,412 Total operating revenues $ 93,980 $ 75,659 $ 87,804
Geographic information by country for long-lived assets	Long-lived assets by geographic area consisted of the following (in millions): December 31, 2017 2016 U.S. $ 26,083 $ 25,359 Canada 1,915 1,816 U.K. and Ireland 1,063 967 Total long-lived assets $ 29,061 $ 28,142

Supplemental Cash Flow Inform44

Supplemental Cash Flow Information (Tables)	12 Months Ended
	Dec. 31, 2017
Supplemental Cash Flow Information [Abstract]
Schedule of cash flows, supplemental disclosures	In order to determine net cash provided by operating activities, net income is adjusted by, among other things, changes in current assets and current liabilities as follows (in millions): Year Ended December 31, 2017 2016 2015 Decrease (increase) in current assets: Receivables, net $ (870 ) $ (1,531 ) $ 1,294 Inventories (516 ) 771 (222 ) Prepaid expenses and other 151 47 (149 ) Increase (decrease) in current liabilities: Accounts payable 1,842 1,556 (1,787 ) Accrued expenses 21 117 (40 ) Taxes other than income taxes payable 172 82 (74 ) Income taxes payable 489 (66 ) (328 ) Changes in current assets and current liabilities $ 1,289 $ 976 $ (1,306 ) Cash flows related to interest and income taxes were as follows (in millions): Year Ended December 31, 2017 2016 2015 Interest paid in excess of amount capitalized $ 457 $ 427 $ 416 Income taxes paid, net 410 444 2,093

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair value of financial assets and liabilities measured on recurring basis	The following tables present information (in millions) about our assets and liabilities recognized at their fair values in our balance sheets categorized according to the fair value hierarchy of the inputs utilized by us to determine the fair values as of December 31, 2017 and 2016 . We have elected to offset the fair value amounts recognized for multiple similar derivative contracts executed with the same counterparty, including any related cash collateral assets or obligations as shown below; however, fair value amounts by hierarchy level are presented in the following tables on a gross basis. We have no derivative contracts that are subject to master netting arrangements that are reflected gross on the balance sheet. December 31, 2017 Total Gross Fair Value Effect of Counter- party Netting Effect of Cash Collateral Netting Net Carrying Value on Balance Sheet Cash Collateral Paid or Received Not Offset Fair Value Hierarchy Level 1 Level 2 Level 3 Assets: Commodity derivative contracts $ 875 $ 19 $ — $ 894 $ (893 ) $ — $ 1 $ — Investments of certain benefit plans 65 — 8 73 n/a n/a 73 n/a Total $ 940 $ 19 $ 8 $ 967 $ (893 ) $ — $ 74 Liabilities: Commodity derivative contracts $ 955 $ 14 $ — $ 969 $ (893 ) $ (76 ) $ — $ (102 ) Environmental credit obligations — 104 — 104 n/a n/a 104 n/a Physical purchase contracts — 6 — 6 n/a n/a 6 n/a Foreign currency contracts 7 — — 7 n/a n/a 7 n/a Total $ 962 $ 124 $ — $ 1,086 $ (893 ) $ (76 ) $ 117 December 31, 2016 Total Gross Fair Value Effect of Counter- party Netting Effect of Cash Collateral Netting Net Carrying Value on Balance Sheet Cash Collateral Paid or Received Not Offset Fair Value Hierarchy Level 1 Level 2 Level 3 Assets: Commodity derivative contracts $ 874 $ 38 $ — $ 912 $ (875 ) $ — $ 37 $ — Foreign currency contracts 3 — — 3 n/a n/a 3 n/a Investments of certain benefit plans 58 — 11 69 n/a n/a 69 n/a Total $ 935 $ 38 $ 11 $ 984 $ (875 ) $ — $ 109 Liabilities: Commodity derivative contracts $ 872 $ 23 $ — $ 895 $ (875 ) $ (20 ) $ — $ (88 ) Environmental credit obligations — 188 — 188 n/a n/a 188 n/a Physical purchase contracts — 5 — 5 n/a n/a 5 n/a Total $ 872 $ 216 $ — $ 1,088 $ (875 ) $ (20 ) $ 193
Carrying amounts and estimated fair value of financial instruments	Financial instruments that we recognize in our balance sheets at their carrying amounts are shown in the following table along with their associated fair values (in millions): December 31, 2017 December 31, 2016 Carrying Amount Fair Value Carrying Amount Fair Value Financial assets: Cash and temporary cash investments $ 5,850 $ 5,850 $ 4,816 $ 4,816 Financial liabilities: Debt (excluding capital leases) 8,310 9,795 7,926 8,882

Price Risk Management Activit46

Price Risk Management Activities (Tables)	12 Months Ended
	Dec. 31, 2017
Derivative Instruments and Hedging Activities Disclosure [Abstract]
Risk management activities by type of risk	As of December 31, 2017 , we had the following outstanding commodity derivative instruments that were used as economic hedges, as well as commodity derivative instruments related to the physical purchase of corn at a fixed price. The information presents the notional volume of outstanding contracts by type of instrument and year of maturity (volumes in thousands of barrels, except those identified as corn contracts that are presented in thousands of bushels and soybean oil contracts that are presented in thousands of pounds). Notional Contract Volumes by Year of Maturity Derivative Instrument 2018 2019 Crude oil and refined petroleum products: Swaps – long 2,655 — Swaps – short 2,590 — Futures – long 83,296 — Futures – short 87,542 — Corn: Futures – long 21,315 35 Futures – short 50,695 665 Physical contracts – long 25,103 630 Soybean oil: Futures – long 76,079 — Futures – short 154,378 — As of December 31, 2017 , we had the following outstanding commodity derivative instruments that were entered into for trading purposes. The information presents the notional volume of outstanding contracts by type of instrument and year of maturity (volumes in thousands of barrels, except those identified as corn contracts that are presented in thousands of bushels). Notional Contract Volumes by Year of Maturity Derivative Instrument 2018 2019 Crude oil and refined petroleum products: Swaps – long 659 — Swaps – short 659 — Futures – long 37,532 — Futures – short 36,919 150 Options – long 153,050 — Options – short 153,050 — Corn: Futures – long 300 —
Fair values of derivative instruments	The following tables provide information about the fair values of our derivative instruments as of December 31, 2017 and 2016 (in millions) and the line items in the balance sheets in which the fair values are reflected. See Note 18 for additional information related to the fair values of our derivative instruments. As indicated in Note 18 , we net fair value amounts recognized for multiple similar derivative contracts executed with the same counterparty under master netting arrangements, including cash collateral assets and obligations. The following tables, however, are presented on a gross asset and gross liability basis, which results in the reflection of certain assets in liability accounts and certain liabilities in asset accounts. Balance Sheet Location December 31, 2017 Asset Derivatives Liability Derivatives Derivatives not designated as hedging instruments Commodity contracts: Futures Receivables, net $ 875 $ 955 Swaps Receivables, net 11 11 Options Receivables, net 8 3 Physical purchase contracts Inventories — 6 Foreign currency contracts Accrued expenses — 7 Total $ 894 $ 982 Balance Sheet Location December 31, 2016 Asset Derivatives Liability Derivatives Derivatives not designated as hedging instruments Commodity contracts: Futures Receivables, net $ 874 $ 872 Swaps Receivables, net 32 21 Options Receivables, net 6 2 Physical purchase contracts Inventories — 5 Foreign currency contracts Receivables, net 3 — Total $ 915 $ 900
Effect of derivative instruments on income	The following tables provide information about the gain or loss recognized in income on our derivative instruments and the income statement line items in which such gains and losses are reflected (in millions). Derivatives Designated as Economic Hedges Location of Gain (Loss) Recognized in Income on Derivatives Year Ended December 31, 2017 2016 2015 Commodity contracts Cost of materials and other $ (344 ) $ (132 ) $ 377 Foreign currency contracts Cost of materials and other (40 ) 16 49 Trading Derivatives Location of Gain Recognized in Income on Derivatives Year Ended December 31, 2017 2016 2015 Commodity contracts Cost of materials and other $ 66 $ 46 $ 45

Quarterly Financial Data (Una47

Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Schedule of quarterly financial information	The following table summarizes quarterly financial data for the years ended December 31, 2017 and 2016 (in millions, except per share amounts). 2017 Quarter Ended March 31 June 30 September 30 December 31 (b) Operating revenues $ 21,772 $ 22,254 $ 23,562 $ 26,392 Gross profit (a) 739 1,063 1,624 1,121 Operating income 537 871 1,338 853 Net income 321 572 863 2,400 Net income attributable to Valero Energy Corporation stockholders 305 548 841 2,371 Earnings per common share 0.68 1.23 1.91 5.43 Earnings per common share – assuming dilution 0.68 1.23 1.91 5.42 2016 Quarter Ended March 31 (c) June 30 (d) September 30 (e) December 31 Operating revenues $ 15,714 $ 19,584 $ 19,649 $ 20,712 Gross profit (a) 997 1,457 1,096 841 Operating income 829 1,231 892 620 Net income 513 843 645 416 Net income attributable to Valero Energy Corporation stockholders 495 814 613 367 Earnings per common share 1.05 1.74 1.33 0.81 Earnings per common share – assuming dilution 1.05 1.73 1.33 0.81 ___________________________ (a) Gross profit is calculated as operating revenues less total cost of sales. (b) During the quarter ended December 31, 2017 , we recognized an income tax benefit of $1.9 billion related to Tax Reform as described in Note 14 . (c) During the quarter ended March 31, 2016, we recognized a favorable noncash lower of cost or market inventory valuation adjustment of $293 million as described in Note 4 . (d) During the quarter ended June 30, 2016, we recognized a favorable noncash lower of cost or market inventory valuation adjustment of $454 million as described in Note 4 and an asset impairment loss of $56 million related to the Aruba Disposition as described in Note 2 . (e) During the quarter ended September 30, 2016, we recognized a tax benefit of $42 million related to the Aruba Disposition as described in Note 2 .

Description of Business, Basi48

Description of Business, Basis of Presentation, and Significant Accounting Policies (Details) gal / yr in Millions, bbl / d in Millions	12 Months Ended
	Dec. 31, 2017gal / yrbbl / drefineryethanol_plantbranded_wholesale_site
Basis of Presentation and Summary of Significant Accounting Policies (Textual)
Number of petroleum refineries owned | refinery	15
Combined total throughput capacity of petroleum refining (barrels per day) | bbl / d	3.1
Number of branded wholesale sites | branded_wholesale_site	7,400
Number of ethanol plants owned | ethanol_plant	11
Combined capacity of ethanol (gallons per year) | gal / yr	1,450
Minimum [Member]
Basis of Presentation and Summary of Significant Accounting Policies (Textual)
Property, plant, and equipment, useful life	25 years
Maximum [Member]
Basis of Presentation and Summary of Significant Accounting Policies (Textual)
Property, plant, and equipment, useful life	30 years

Aruba Disposition (Details)

Aruba Disposition (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		12 Months Ended
	Jun. 30, 2016	Sep. 30, 2016	Jun. 30, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Aruba Disposition (Textual)
Asset impairment loss			$ 56	$ 0	$ 56	$ 0
Tax benefit on disposition		$ 42		$ 949	(765)	$ (1,870)
Refining [Member] | Aruba Disposition [Member]
Aruba Disposition (Textual)
Tax benefit on disposition					$ 42
Aruba Terminal [Member]
Aruba Disposition (Textual)
Asset impairment loss	$ 56
Aruba Terminal [Member] | Refining [Member]
Aruba Disposition (Textual)
Asset impairment loss	$ 56

Receivables (Details)

Receivables (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Receivables
Accounts receivable	$ 6,786	$ 5,687
Commodity derivative and foreign currency contract receivables	102	129
Other receivables	67	117
Receivables, gross	6,955	5,933
Allowance for doubtful accounts	(33)	(32)
Receivables, net	$ 6,922	$ 5,901

Inventories (Details)

Inventories (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Schedule of Inventories
Refinery feedstocks			$ 2,427	$ 2,068
Refined petroleum products and blendstocks			3,459	3,153
Ethanol feedstocks and products			242	238
Materials and supplies			256	250
Inventories			6,384	5,709
Inventories (Textual)
Excess of market value over carrying amount of LIFO inventories			3,000	1,900
Inventory not valued at LIFO			1,000	641
Lower of cost or market inventory valuation adjustment (benefit)	$ (454)	$ (293)	$ 0	(747)	$ 790
Effect of LIFO inventory liquidation on income				$ 120

Property, Plant, and Equipmen52

Property, Plant, and Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant, and Equipment, Net
Property, plant, and equipment, at cost	$ 40,010	$ 37,733
Accumulated depreciation	(12,530)	(11,261)
Property, plant, and equipment, net	27,480	26,472
Property, Plant, and Equipment (Textual)
Property, plant, and equipment, assets under capital leases	635	118
Accumulated amortization on assets under capital leases	72	45
Depreciation expense related to continuing operations	1,300	1,300	$ 1,300
Land [Member]
Property, Plant, and Equipment, Net
Property, plant, and equipment, at cost	411	400
Crude Oil Processing Facilities [Member]
Property, Plant, and Equipment, Net
Property, plant, and equipment, at cost	30,109	29,754
Transportation and Terminaling Facilities [Member]
Property, Plant, and Equipment, Net
Property, plant, and equipment, at cost	4,335	3,692
Grain Processing Equipment [Member]
Property, Plant, and Equipment, Net
Property, plant, and equipment, at cost	903	855
Administrative Buildings [Member]
Property, Plant, and Equipment, Net
Property, plant, and equipment, at cost	910	838
Other [Member]
Property, Plant, and Equipment, Net
Property, plant, and equipment, at cost	2,068	1,464
Construction in Progress [Member]
Property, Plant, and Equipment, Net
Property, plant, and equipment, at cost	$ 1,274	$ 730

Deferred Charges and Other As53

Deferred Charges and Other Assets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Deferred Charges and Other Assets
Deferred turnaround and catalyst costs, net	$ 1,520	$ 1,614
Income taxes receivable	673	447
Investments in joint ventures	530	201
Intangible assets, net	142	148
Other	501	491
Deferred charges and other assets, net	3,366	2,901
Deferred Charges and Other Assets (Textual)
Amortization expense, deferred refinery turnaround and catalyst costs and other assets	$ 650	$ 575	$ 542

Accrued Expenses and Other Lo54

Accrued Expenses and Other Long-Term Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Accrued Expenses
Defined benefit plan liabilities, current	$ 33	$ 32
Wage and other employee-related liabilities, current	278	225
Environmental liabilities, current	30	29
Environmental credit obligations, current	152	214
Accrued interest expense, current	105	104
Other accrued liabilities, current	114	90
Accrued expenses	712	694
Other Long-Term Liabilities
Defined benefit plan liabilities, noncurrent	776	742
Wage and other employee-related liabilities, noncurrent	111	103
Uncertain tax position liabilities, noncurrent	723	465
Repatriation tax liability, noncurrent	597	0
Environmental liabilities, noncurrent	232	223
Other accrued liabilities, noncurrent	290	211
Other long-term liabilities	$ 2,729	$ 1,744

Debt and Capital Lease Obliga55

Debt and Capital Lease Obligations (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Debt Instruments [Abstract]
Net unamortized debt issuance costs and other	$ (73)	$ (79)
Total debt	8,310	7,926
Capital lease obligations	562	75
Total debt and capital lease obligations	8,872	8,001
Less current portion	122	115
Debt and capital lease obligations, less current portion	8,750	7,886
Credit Facilities [Member] | Valero Revolver [Member]
Debt Instruments [Abstract]
Long-term debt at stated values	0	0
Credit Facilities [Member] | VLP Revolver [Member]
Debt Instruments [Abstract]
Long-term debt at stated values	410	30
Credit Facilities [Member] | Canadian Revolver [Member]
Debt Instruments [Abstract]
Long-term debt at stated values	0	0
Credit Facilities [Member] | Accounts Receivable Sales Facility [Member]
Debt Instruments [Abstract]
Long-term debt at stated values	100	100
Senior Notes [Member] | Senior Notes Due In June 2037 [Member]
Debt Instruments [Abstract]
Long-term debt at stated values	$ 1,500	1,500
Interest rate of notes (percent)	6.625%
Senior Notes [Member] | Senior Notes Due in 2026 [Member]
Debt Instruments [Abstract]
Long-term debt at stated values	$ 1,250	$ 1,250
Interest rate of notes (percent)	3.40%	3.40%
Senior Notes [Member] | Senior Notes Due In 2020 [Member]
Debt Instruments [Abstract]
Long-term debt at stated values	$ 850	$ 850
Interest rate of notes (percent)	6.125%
Senior Notes [Member] | Senior Notes Due In 2019 [Member]
Debt Instruments [Abstract]
Long-term debt at stated values	$ 750	750
Interest rate of notes (percent)	9.375%
Senior Notes [Member] | Senior Notes Due In 2032 [Member]
Debt Instruments [Abstract]
Long-term debt at stated values	$ 750	750
Interest rate of notes (percent)	7.50%
Senior Notes [Member] | Senior Notes Due in 2045 [Member]
Debt Instruments [Abstract]
Long-term debt at stated values	$ 650	650
Interest rate of notes (percent)	4.90%		4.90%
Senior Notes [Member] | Senior Notes Due in 2025 [Member]
Debt Instruments [Abstract]
Long-term debt at stated values	$ 600	600
Interest rate of notes (percent)	3.65%		3.65%
Senior Notes [Member] | Senior Notes Due In 2039 [Member]
Debt Instruments [Abstract]
Long-term debt at stated values	$ 250	250
Interest rate of notes (percent)	10.50%
Senior Notes [Member] | Senior Notes Due In 2030 [Member]
Debt Instruments [Abstract]
Long-term debt at stated values	$ 200	200
Interest rate of notes (percent)	8.75%
Senior Notes [Member] | Senior Notes Due In 2097 [Member]
Debt Instruments [Abstract]
Long-term debt at stated values	$ 100	100
Interest rate of notes (percent)	7.45%
Senior Notes [Member] | Senior Notes Due In 2037 [Member]
Debt Instruments [Abstract]
Long-term debt at stated values	$ 24	24
Interest rate of notes (percent)	6.75%
Senior Notes [Member] | VLP Senior Notes Due in 2026 [Member]
Debt Instruments [Abstract]
Long-term debt at stated values	$ 500	$ 500
Interest rate of notes (percent)	4.375%	4.375%
Revenue Bonds [Member] | Gulf Opportunity Zone Revenue Bonds Series 2010 [Member]
Debt Instruments [Abstract]
Long-term debt at stated values	$ 300	$ 300
Interest rate of notes (percent)	4.00%
Debentures [Member] | Debenture Due In 2026 [Member]
Debt Instruments [Abstract]
Long-term debt at stated values	$ 100	100
Interest rate of notes (percent)	7.65%
Secured Debt [Member] | Senior Secured Credit Agreement Due in 2023 [Member]
Debt Instruments [Abstract]
Long-term debt at stated values	$ 49	$ 51

Debt, Bank Credit Facilities (D

Debt, Bank Credit Facilities (Details)	6 Months Ended	9 Months Ended	10 Months Ended	12 Months Ended
	Jun. 29, 2017USD ($)	Sep. 30, 2017CAD	Oct. 31, 2017	Dec. 31, 2017CADrenewalquarter	Dec. 31, 2017USD ($)quarter	Dec. 31, 2016CAD	Dec. 31, 2016USD ($)	Dec. 31, 2015CAD	Dec. 31, 2015USD ($)	Dec. 31, 2017USD ($)renewal
Valero Revolver [Member] | Credit Facilities [Member]
Line of Credit Facility
Line of credit facility, maximum borrowing capacity										$ 3,000,000,000
Line of credit facility, expiration date				Nov. 30, 2020	Nov. 30, 2020
Line of credit facility issued and outstanding										0
Line of credit facility, remaining borrowing capacity										2,946,000,000
Credit Facilities (Textual)
Line of credit facility, accordion feature, higher borrowing capacity option										$ 4,500,000,000
Line of credit facility, number of renewal options | renewal				2						2
Line of credit facility, duration of renewal option (in years)				1 year	1 year
Borrowings from long-term lines of credit					$ 0		$ 0		$ 0
Repayments of long-term lines of credit					$ 0		$ 0		0
Valero Revolver Letter of Credit [Member] | Credit Facilities [Member]
Line of Credit Facility
Line of credit facility, maximum borrowing capacity										$ 2,000,000,000
Line of credit facility issued and outstanding										54,000,000
VLP Revolver [Member] | Credit Facilities [Member]
Line of Credit Facility
Line of credit facility, maximum borrowing capacity										750,000,000
Line of credit facility, expiration date				Nov. 30, 2020	Nov. 30, 2020
Line of credit facility issued and outstanding										410,000,000
Line of credit facility, remaining borrowing capacity										340,000,000
Credit Facilities (Textual)
Line of credit facility, accordion feature, higher borrowing capacity option										$ 1,000,000,000
Line of credit facility, number of renewal options | renewal				2						2
Line of credit facility, duration of renewal option (in years)				1 year	1 year
Interest rate of credit facility at period end (percent)				2.875%			2.3125%			2.875%
Number of prior quarterly reporting periods used for debt to EBITDA ratio | quarter				4	4
Repayments of long-term lines of credit					$ 0		$ 494,000,000		25,000,000
VLP Revolver [Member] | Credit Facilities [Member] | Parkway Pipeline LLC [Member]
Credit Facilities (Textual)
Borrowings from long-term lines of credit					118,000,000
VLP Revolver [Member] | Credit Facilities [Member] | Valero Partners Port Arthur, LLC [Member]
Credit Facilities (Textual)
Borrowings from long-term lines of credit					$ 262,000,000
VLP Revolver [Member] | Credit Facilities [Member] | McKee Terminal Services Business [Member]
Credit Facilities (Textual)
Borrowings from long-term lines of credit							139,000,000
VLP Revolver [Member] | Credit Facilities [Member] | Meraux and Three Rivers Terminal Services Business [Member]
Credit Facilities (Textual)
Borrowings from long-term lines of credit							$ 210,000,000
VLP Revolver [Member] | Credit Facilities [Member] | Houston and St. Charles Terminal Services Business [Member]
Credit Facilities (Textual)
Borrowings from long-term lines of credit									200,000,000
VLP Revolver [Member] | Credit Facilities [Member] | Maximum [Member]
Credit Facilities (Textual)
Debt to EBITDA ratio as per terms of revolver				5						5
VLP Revolver Letter of Credit [Member] | Credit Facilities [Member]
Line of Credit Facility
Line of credit facility, maximum borrowing capacity										$ 100,000,000
Line of credit facility issued and outstanding										0
Canadian Revolver [Member] | Credit Facilities [Member]
Line of Credit Facility
Line of credit facility, maximum borrowing capacity | CAD		CAD 25,000,000		CAD 75,000,000
Line of credit facility, expiration date		Nov. 30, 2017		Nov. 30, 2018	Nov. 30, 2018
Line of credit facility issued and outstanding | CAD				CAD 0
Line of credit facility, remaining borrowing capacity | CAD				65,000,000
Credit Facilities (Textual)
Borrowings from long-term lines of credit | CAD				0		CAD 0		CAD 0
Repayments of long-term lines of credit | CAD				0		CAD 0		CAD 0
Canadian Revolver Letter of Credit [Member] | Credit Facilities [Member]
Line of Credit Facility
Line of credit facility issued and outstanding | CAD				CAD 10,000,000
Accounts Receivable Sales Facility [Member] | Credit Facilities [Member]
Line of Credit Facility
Line of credit facility, maximum borrowing capacity										1,300,000,000
Line of credit facility, expiration date				Jul. 31, 2018	Jul. 31, 2018
Line of credit facility issued and outstanding										100,000,000
Line of credit facility, remaining borrowing capacity										$ 1,200,000,000
Credit Facilities (Textual)
Interest rate of credit facility at period end (percent)				2.0387%			1.3422%			2.0387%
Borrowings from long-term lines of credit					$ 0		$ 0		0
Repayments of long-term lines of credit					$ 0		0		$ 0
Designated pool of accounts receivable							$ 2,000,000,000			$ 2,300,000,000
Committed Letter of Credit Facility Expires November 2018 [Member] | Credit Facilities [Member]
Line of Credit Facility
Line of credit facility, maximum borrowing capacity										100,000,000
Line of credit facility, expiration date			Nov. 30, 2017	Nov. 30, 2018	Nov. 30, 2018
Line of credit facility issued and outstanding										0
Line of credit facility, remaining borrowing capacity										100,000,000
Committed Letter of Credit Facility Expires June 2017 [Member] | Credit Facilities [Member]
Line of Credit Facility
Line of credit facility, maximum borrowing capacity	$ 125,000,000
Line of credit facility, expiration date	Jun. 30, 2017
Uncommitted Letter of Credit Facility [Member]
Line of Credit Facility
Line of credit facility issued and outstanding										$ 249,000,000

Debt, Non-Bank Debt (Details)

Debt, Non-Bank Debt (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2017
Senior Notes [Member]
Non-Bank Debt (Textual)
Proceeds from issuance of senior long-term debt		$ 1,246,000,000
Debt issuance costs		12,000,000
Senior Notes [Member] | Senior Notes Due in 2026 [Member]
Non-Bank Debt (Textual)
Face amount of long-term debt issuance	$ 1,250,000,000
Interest rate of notes (percent)	3.40%		3.40%
Maturity date of long-term debt issuance	Sep. 15, 2026
Proceeds from issuance of senior long-term debt	$ 1,246,000,000
Payments of debt issuance costs	$ 10,000,000
Senior Notes [Member] | Senior Notes Due in June 2017 [Member]
Non-Bank Debt (Textual)
Interest rate of notes (percent)	6.125%
Maturity date of long-term debt issuance	Jun. 15, 2017
Early repayment of senior debt	$ 778,000,000
Debt instrument, redemption price, percentage of principal amount redeemed (percent)	103.70%
Senior Notes [Member] | Senior Notes Due in October 2017 [Member]
Non-Bank Debt (Textual)
Interest rate of notes (percent)	7.20%
Maturity date of long-term debt issuance	Oct. 15, 2017
Early repayment of senior debt	$ 213,000,000
Debt instrument, redemption price, percentage of principal amount redeemed (percent)	106.27%
Senior Notes [Member] | VLP Senior Notes Due in 2026 [Member]
Non-Bank Debt (Textual)
Face amount of long-term debt issuance	$ 500,000,000
Interest rate of notes (percent)	4.375%		4.375%
Maturity date of long-term debt issuance	Dec. 15, 2026
Proceeds from issuance of senior long-term debt	$ 500,000,000
Debt issuance costs	$ 4,000,000
Senior Notes [Member] | Senior Notes Due in 2025 [Member]
Non-Bank Debt (Textual)
Face amount of long-term debt issuance		$ 600,000,000
Interest rate of notes (percent)		3.65%	3.65%
Maturity date of long-term debt issuance		Mar. 15, 2025
Senior Notes [Member] | Senior Notes Due in 2045 [Member]
Non-Bank Debt (Textual)
Face amount of long-term debt issuance		$ 650,000,000
Interest rate of notes (percent)		4.90%	4.90%
Maturity date of long-term debt issuance		Mar. 15, 2045
Senior Notes [Member] | Senior Notes Due In 2015 [Member]
Non-Bank Debt (Textual)
Interest rate of notes (percent)		4.50%
Debt repayments		$ 400,000,000
Debentures [Member] | Debenture Due In 2015 [Member]
Non-Bank Debt (Textual)
Interest rate of notes (percent)		8.75%
Debt repayments		$ 75,000,000

Debt, Interest Incurred (Detail

Debt, Interest Incurred (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Interest and Debt Expense, Net of Capitalized Interest
Interest and debt expense	$ 539	$ 511	$ 504
Less capitalized interest	71	65	71
Interest and debt expense, net of capitalized interest	$ 468	$ 446	$ 433

Debt, Other Disclosures (Detail

Debt, Other Disclosures (Details) - USD ($) $ in Millions	1 Months Ended
	Jan. 31, 2017	Dec. 31, 2017	Dec. 31, 2016
Principal Payments Due on Debt
2,018		$ 106
2,019		756
2,020		1,266
2,021		6
2,022		6
Thereafter		6,243
Net unamortized debt issuance costs and other		(73)	$ (79)
Total debt		8,310	7,926
Future Minimum Rentals on Capital Lease Obligations
2,018		55
2,019		55
2,020		53
2,021		52
2,022		54
Thereafter		969
Total minimum lease payments		1,238
Less amount representing interest		676
Total capital lease obligations		$ 562	$ 75
Capital Lease Obligations [Member]
Capital Lease Obligations (Textual)
Capital lease obligations incurred	$ 490
Debt instrument, term	10 years
Duration of renewal option	10 years
Assets Held under Capital Leases [Member]
Capital Lease Obligations (Textual)
Capital lease assets recognized	$ 490

Commitments and Contingencies60

Commitments and Contingencies (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Future Minimum Rental Payments
2,018	$ 359
2,019	236
2,020	148
2,021	104
2,022	74
Thereafter	366
Total minimum rental payments	1,287
Minimum rentals to be received under subleases	15
Rental Expense, Net of Sublease Rental Income
Minimum rental expense	691	$ 739	$ 732
Contingent rental expense	21	70	105
Total rental expense	712	809	837
Less sublease rental income	54	31	46
Rental expense, net of sublease rental income	$ 658	$ 778	$ 791

Commitments and Contingencies,

Commitments and Contingencies, Narrative (Details) $ in Millions	Feb. 01, 2018USD ($)	Dec. 31, 2017USD ($)bbl / drenewalMBbls	Dec. 31, 2017USD ($)bbl / drenewalMBbls	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)bbl / drenewalMBbls	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Jun. 30, 2019USD ($)	Jun. 30, 2019USD ($)	Jan. 01, 2020USD ($)	Jan. 31, 2018bbl / dMBbls
Commitments And Contingencies (Textual)
Total project cost		$ 40,010	$ 40,010		$ 40,010	$ 37,733
Contributions					406	4	$ 141
Payments to acquire interest in project					$ 72	0	$ 0
Terminalling Agreement [Member] | MVP Terminalling, LLC (MVP) [Member]
Commitments And Contingencies (Textual)
Initial term of agreement			12 years
Number of renewal options | renewal		2	2		2
Duration of renewal option			5 years
MVP Terminal [Member]
Commitments And Contingencies (Textual)
Terminal storage capacity (barrels) | MBbls		5,000	5,000		5,000
Contributions			$ 81
MVP Terminal [Member] | Magellan Midstream Partners LP (Magellan) [Member]
Commitments And Contingencies (Textual)
Long term liability		$ 94	$ 94		$ 94
Central Texas Pipeline [Member]
Commitments And Contingencies (Textual)
Undivided interest in project (percent)		40.00%	40.00%		40.00%
Pipeline capacity (barrels per day) | bbl / d		150,000	150,000		150,000
Payments to acquire interest in project		$ 7
Sunrise Pipeline System [Member] | Subsequent Event [Member]
Commitments And Contingencies (Textual)
Undivided interest in project (percent)											20.00%
Pipeline capacity (barrels per day) | bbl / d											500,000
Payments to acquire interest in project	$ 34
Colorado City Storage Tanks [Member] | Subsequent Event [Member]
Commitments And Contingencies (Textual)
Terminal storage capacity (barrels) | MBbls											270
Construction in Progress [Member]
Commitments And Contingencies (Textual)
Total project cost		1,274	$ 1,274		$ 1,274	$ 730
Construction in Progress [Member] | MVP Terminal [Member]
Commitments And Contingencies (Textual)
Total project cost		174	174		174
Expected Impact [Member] | MVP Terminal [Member]
Commitments And Contingencies (Textual)
Contributions										$ 420
Expected Impact [Member] | Central Texas Pipeline [Member]
Commitments And Contingencies (Textual)
Payments to acquire interest in project									$ 170
Expected Impact [Member] | Sunrise Pipeline System [Member]
Commitments And Contingencies (Textual)
Payments to acquire interest in project				$ 101				$ 135
Minimum [Member]
Commitments And Contingencies (Textual)
Range of possible loss contingency		0	0		0
Minimum [Member] | Expected Impact [Member] | Construction in Progress [Member] | MVP Terminal [Member]
Commitments And Contingencies (Textual)
Total project cost										840
Maximum [Member]
Commitments And Contingencies (Textual)
Range of possible loss contingency		$ 200	$ 200		$ 200
Maximum [Member] | Expected Impact [Member] | Construction in Progress [Member] | MVP Terminal [Member]
Commitments And Contingencies (Textual)
Total project cost										$ 1,400
Valero Energy Corporation [Member] | MVP Terminal [Member]
Commitments And Contingencies (Textual)
Terminal storage capacity (barrels) | MBbls		4,000	4,000		4,000
MVP Terminalling, LLC (MVP) [Member] | Variable Interest Entity, Not Primary Beneficiary [Member]
Commitments And Contingencies (Textual)
Membership interest (percent)			50.00%

Equity, Stock Related Disclosur

Equity, Stock Related Disclosures (Details) - USD ($)	Jan. 23, 2018	Nov. 24, 2015	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Sep. 21, 2016	Sep. 16, 2016	Jul. 13, 2015	Feb. 28, 2008
Share Activity Rollforward
Treasury stock, beginning balance (shares)			(222,000,024)
Treasury stock, ending balance (shares)			(239,603,534)	(222,000,024)
Equity (Textual)
Preferred stock authorized (shares)			20,000,000
Preferred stock par value per share (in dollars per share)			$ 0.01
Preferred stock outstanding (shares)			0	0
Stock repurchases under buyback program			$ 1,307,000,000	$ 1,262,000,000	$ 2,667,000,000
Remaining amount authorized under stock purchase programs			1,200,000,000
Proceeds from issuance of Valero Energy Partners LP common units			$ 36,000,000	$ 10,000,000	189,000,000
Public Offering [Member] | Valero Energy Partners LP [Member]
Equity (Textual)
Aggregate offering price under equity distribution agreement							$ 350,000,000
Units sold in the offering (shares)		4,250,000	742,897	223,083
Proceeds from issuance of Valero Energy Partners LP common units		$ 189,000,000	$ 35,000,000	$ 9,000,000
Price per unit (in dollars per unit)		$ 46.25
Subsequent Event [Member] | Dividend Declared [Member]
Equity (Textual)
Dividends payable, date declared	Jan. 23, 2018
Dividends payable (in dollars per share)	$ 0.80
Dividends payable, date to be paid	Mar. 6, 2018
Dividends payable, date of record	Feb. 13, 2018
Common Stock Repurchase Programs [Member]
Equity (Textual)
Stock repurchases under buyback program			$ 1,300,000,000	$ 1,300,000,000	$ 2,700,000,000
$3 Billion Program Approved February 2008 [Member]
Equity (Textual)
Authorized amount under stock purchase program									$ 3,000,000,000
Stock Repurchase Program Approved July 2015 [Member]
Equity (Textual)
Authorized amount under stock purchase program								$ 2,500,000,000
Stock Repurchase Program Approved September 2016 [Member]
Equity (Textual)
Authorized amount under stock purchase program						$ 2,500,000,000
Stock Repurchase Program Approved January 2018 [Member] | Subsequent Event [Member]
Equity (Textual)
Authorized amount under stock purchase program	$ 2,500,000,000
Common Stock [Member]
Share Activity Rollforward
Common stock, beginning balance (shares)			673,000,000	673,000,000	673,000,000
Common stock, ending balance (shares)			673,000,000	673,000,000	673,000,000
Treasury Stock [Member]
Share Activity Rollforward
Treasury stock, beginning balance (shares)			(222,000,000)	(200,000,000)	(159,000,000)
Transactions in connection with stock-based compensation plans (shares)			1,000,000	1,000,000	1,000,000
Stock purchases under purchase program (shares)			(19,000,000)	(23,000,000)	(42,000,000)
Treasury stock, ending balance (shares)			(240,000,000)	(222,000,000)	(200,000,000)
Equity (Textual)
Stock repurchases under buyback program			$ 1,307,000,000	$ 1,262,000,000	$ 2,667,000,000

Equity, Income Tax Effects on O

Equity, Income Tax Effects on Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Other Comprehensive Income (Loss), before Tax
Other comprehensive income (loss) before income tax expense (benefit)		$ 449	$ (513)	$ (549)
Other Comprehensive Income (Loss), Tax
Income tax expense (benefit) related to items of other comprehensive income (loss)		(21)	(37)	17
Other Comprehensive Income (Loss), Net of Tax
Reclassification from accumulated other comprehensive income (loss), current period, net of tax		12	7	19
Other comprehensive income (loss)		470	(476)	(566)
Foreign Currency Translation Adjustment [Member]
Other Comprehensive Income (Loss), before Tax
Other comprehensive income (loss), before reclassifications, before tax		514	(415)	(606)
Other Comprehensive Income (Loss), Tax
Other comprehensive income (loss), before reclassifications, tax expense (benefit)		0	0	0
Other Comprehensive Income (Loss), Net of Tax
Other comprehensive income (loss), before reclassifications, net of tax		514	(415)	(606)
Net Actuarial Gain (Loss) [Member]
Other Comprehensive Income (Loss), before Tax
Other comprehensive income (loss), before reclassifications, before tax		(79)	(110)	50
Reclassification from accumulated other comprehensive income (loss), current period, before tax	[1]	50	48	62
Other Comprehensive Income (Loss), Tax
Other comprehensive income (loss), before reclassifications, tax expense (benefit)		(29)	(34)	15
Reclassification from accumulated other comprehensive income (loss), current period, tax expense (benefit)		18	18	22
Other Comprehensive Income (Loss), Net of Tax
Other comprehensive income (loss), before reclassifications, net of tax		(50)	(76)	35
Reclassification from accumulated other comprehensive income (loss), current period, net of tax		32	30	40
Prior Service (Cost) Credit [Member]
Other Comprehensive Income (Loss), before Tax
Other comprehensive income (loss), before reclassifications, before tax		(4)		(22)
Reclassification from accumulated other comprehensive income (loss), current period, before tax	[1]	(36)	(36)	(40)
Other Comprehensive Income (Loss), Tax
Other comprehensive income (loss), before reclassifications, tax expense (benefit)		(1)		(8)
Reclassification from accumulated other comprehensive income (loss), current period, tax expense (benefit)		(13)	(13)	(14)
Other Comprehensive Income (Loss), Net of Tax
Other comprehensive income (loss), before reclassifications, net of tax		(3)		(14)
Reclassification from accumulated other comprehensive income (loss), current period, net of tax		(23)	(23)	(26)
Miscellaneous Gain (Loss) [Member]
Other Comprehensive Income (Loss), before Tax
Other comprehensive income (loss), before reclassifications, before tax		0	0
Other Comprehensive Income (Loss), Tax
Other comprehensive income (loss), before reclassifications, tax expense (benefit)		3	(8)
Other Comprehensive Income (Loss), Net of Tax
Other comprehensive income (loss), before reclassifications, net of tax		(3)	8
Curtailment and Settlement Loss [Member]
Other Comprehensive Income (Loss), before Tax
Reclassification from accumulated other comprehensive income (loss), current period, before tax	[1]	4	0	7
Other Comprehensive Income (Loss), Tax
Reclassification from accumulated other comprehensive income (loss), current period, tax expense (benefit)		1		2
Other Comprehensive Income (Loss), Net of Tax
Reclassification from accumulated other comprehensive income (loss), current period, net of tax		3		5
Net Gain (Loss) on Pension and Other Postretirement Benefits [Member]
Other Comprehensive Income (Loss), before Tax
Reclassification from accumulated other comprehensive income (loss), current period, before tax		18	12	29
Other comprehensive income (loss) before income tax expense (benefit)		(65)	(98)	57
Other Comprehensive Income (Loss), Tax
Reclassification from accumulated other comprehensive income (loss), current period, tax expense (benefit)		6	5	10
Income tax expense (benefit) related to items of other comprehensive income (loss)		(21)	(37)	17
Other Comprehensive Income (Loss), Net of Tax
Other comprehensive income (loss)		$ (44)	$ (61)	$ 40
[1]	These accumulated other comprehensive loss components are included in the computation of net periodic benefit cost, as further discussed in Note 12. Net periodic benefit cost is reflected in operating expenses (excluding depreciation and amortization expense) and general and administrative expenses (excluding depreciation and amortization expense).

Equity, Changes in Accumulated

Equity, Changes in Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Changes in Accumulated Other Comprehensive Income (Loss) by Component, Net of Tax
Beginning balance, accumulated other comprehensive income (loss), net of tax	$ 20,024
Ending balance, accumulated other comprehensive income (loss), net of tax	21,991	$ 20,024
Accumulated Other Comprehensive Income (Loss) [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component, Net of Tax
Beginning balance, accumulated other comprehensive income (loss), net of tax	(1,410)	(933)	$ (367)
Other comprehensive income (loss) before reclassifications	458	(484)	(585)
Amounts reclassified from accumulated other comprehensive income (loss)	12	7	19
Net other comprehensive income (loss)	470	(477)	(566)
Ending balance, accumulated other comprehensive income (loss), net of tax	(940)	(1,410)	(933)
Foreign Currency Translation Adjustment [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component, Net of Tax
Beginning balance, accumulated other comprehensive income (loss), net of tax	(1,021)	(605)	1
Other comprehensive income (loss) before reclassifications	514	(416)	(606)
Amounts reclassified from accumulated other comprehensive income (loss)	0	0	0
Net other comprehensive income (loss)	514	(416)	(606)
Ending balance, accumulated other comprehensive income (loss), net of tax	(507)	(1,021)	(605)
Defined Benefit Plan Items Adjustment [Member]
Changes in Accumulated Other Comprehensive Income (Loss) by Component, Net of Tax
Beginning balance, accumulated other comprehensive income (loss), net of tax	(389)	(328)	(368)
Other comprehensive income (loss) before reclassifications	(56)	(68)	21
Amounts reclassified from accumulated other comprehensive income (loss)	12	7	19
Net other comprehensive income (loss)	(44)	(61)	40
Ending balance, accumulated other comprehensive income (loss), net of tax	$ (433)	$ (389)	$ (328)

Equity, Reclassification Out of

Equity, Reclassification Out of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Gains (losses) reclassified out of accumulated other comprehensive income (loss)
Net of tax		$ (12)	$ (7)	$ (19)
Net Actuarial Gain (Loss) [Member]
Amortization of items related to defined benefit pension plans:
Reclassification from accumulated other comprehensive income (loss), current period, before tax	[1]	(50)	(48)	(62)
Tax benefit		18	18	22
Gains (losses) reclassified out of accumulated other comprehensive income (loss)
Net of tax		(32)	(30)	(40)
Prior Service (Cost) Credit [Member]
Amortization of items related to defined benefit pension plans:
Reclassification from accumulated other comprehensive income (loss), current period, before tax	[1]	36	36	40
Tax benefit		(13)	(13)	(14)
Gains (losses) reclassified out of accumulated other comprehensive income (loss)
Net of tax		23	23	26
Curtailment and Settlement Loss [Member]
Amortization of items related to defined benefit pension plans:
Reclassification from accumulated other comprehensive income (loss), current period, before tax	[1]	(4)	0	(7)
Tax benefit		1		2
Gains (losses) reclassified out of accumulated other comprehensive income (loss)
Net of tax		(3)		(5)
Net Gain (Loss) on Pension and Other Postretirement Benefits [Member]
Amortization of items related to defined benefit pension plans:
Reclassification from accumulated other comprehensive income (loss), current period, before tax		(18)	(12)	(29)
Tax benefit		$ 6	$ 5	$ 10
[1]	These accumulated other comprehensive loss components are included in the computation of net periodic benefit cost, as further discussed in Note 12. Net periodic benefit cost is reflected in operating expenses (excluding depreciation and amortization expense) and general and administrative expenses (excluding depreciation and amortization expense).

Variable Interest Entities, Con

Variable Interest Entities, Consolidated (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)refinery	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)	Dec. 31, 2014USD ($)
Assets
Cash and temporary cash investments	$ 5,850	$ 4,816	$ 4,114	$ 3,689
Property, plant, and equipment, net	27,480	26,472
Liabilities
Current liabilities	11,071	8,328
Debt and capital lease obligations, less current portion	$ 8,750	7,886
Variable Interest Entity (Textual)
Number of refineries impacted by VLP operations | refinery	10
Variable Interest Entity, Primary Beneficiary [Member]
Assets
Cash and temporary cash investments	$ 179	253
Other current assets	72	90
Property, plant, and equipment, net	2,029	1,353
Liabilities
Current liabilities	95	39
Debt and capital lease obligations, less current portion	948	571
Variable Interest Entity, Primary Beneficiary [Member] | Valero Energy Partners LP [Member]
Assets
Cash and temporary cash investments	42	71
Other current assets	2	3
Property, plant, and equipment, net	1,416	865
Liabilities
Current liabilities	27	15
Debt and capital lease obligations, less current portion	905	525
Variable Interest Entity, Primary Beneficiary [Member] | Diamond Green Diesel Holdings LLC [Member]
Assets
Cash and temporary cash investments	123	167
Other current assets	66	87
Property, plant, and equipment, net	435	355
Liabilities
Current liabilities	33	17
Debt and capital lease obligations, less current portion	$ 0	0
Variable Interest Entity (Textual)
Ownership interest (percent)	50.00%
Maximum percentage of joint venture construction costs financed (percent)	60.00%
Variable Interest Entity, Primary Beneficiary [Member] | VPM Terminals [Member]
Assets
Cash and temporary cash investments	$ 1
Other current assets	4
Property, plant, and equipment, net	51
Liabilities
Current liabilities	26
Debt and capital lease obligations, less current portion	0
Variable Interest Entity, Primary Beneficiary [Member] | Other Variable Interest Entities [Member]
Assets
Cash and temporary cash investments	13	15
Other current assets	0	0
Property, plant, and equipment, net	127	133
Liabilities
Current liabilities	9	7
Debt and capital lease obligations, less current portion	$ 43	$ 46
Variable Interest Entity, Primary Beneficiary [Member] | Limited Partner [Member] | Valero Energy Partners LP [Member]
Variable Interest Entity (Textual)
Ownership interest (percent)	66.20%
Variable Interest Entity, Primary Beneficiary [Member] | General Partner [Member] | Valero Energy Partners LP [Member]
Variable Interest Entity (Textual)
Ownership interest (percent)	2.00%
Variable Interest Entity, Primary Beneficiary, Aggregated Disclosure [Member] | Other Variable Interest Entities [Member]
Variable Interest Entity (Textual)
Ownership interest (percent)	50.00%
Variable Interest Entity, Not Primary Beneficiary [Member] | Limited Partner [Member] | Valero Energy Partners LP [Member]
Variable Interest Entity (Textual)
Ownership interest (percent)	31.80%

Variable Interest Entities, Non

Variable Interest Entities, Non-Consolidated (Details) - MVP Terminalling, LLC (MVP) [Member] $ in Millions	4 Months Ended
	Dec. 31, 2017USD ($)member
Variable Interest Entity, Primary Beneficiary [Member] | Magellan Midstream Partners LP (Magellan) [Member]
Variable Interest Entity (Textual)
Ownership interest (percent)	50.00%
Variable Interest Entity, Not Primary Beneficiary [Member]
Variable Interest Entity (Textual)
Ownership interest (percent)	50.00%
Number of members | member	2
Maximum exposure to loss	$ 80
VLO equity investment in MVP	$ 80

Employee Benefit Plans (Details

Employee Benefit Plans (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Changes in plan assets (a):
Fair value of plan assets at beginning of year		$ 2,097
Fair value of plan assets at end of year		2,428		$ 2,097
Defined Benefit Plan, Amounts Recognized in Balance Sheet
Accrued expenses		(33)		(32)
Other long-term liabilities		(776)		(742)
Employee Benefit Plans (Textual)
Contributions to defined contribution plans		70		67		$ 65
Pension Plans [Member]
Changes in benefit obligation:
Benefit obligation at beginning of year		2,567	[1]	2,365
Service cost		123		111		109
Interest cost		86		84		98
Participant contributions		0		0
Benefits paid		(158)		(130)
Actuarial (gain) loss		286		171
Other		22		(34)
Benefit obligation at end of year		2,926	[1]	2,567	[1]	2,365
Changes in plan assets (a):
Fair value of plan assets at beginning of year	[1]	2,097		1,947
Actual return on plan assets	[1]	363		165
Valero contributions	[1]	110		141
Participant contributions	[1]	0		0
Benefits paid	[1]	(158)		(130)
Other	[1]	16		(26)
Fair value of plan assets at end of year	[1]	2,428		2,097		1,947
Reconciliation of funded status (a):
Funded status as of end of year	[1]	(498)		(470)
Accumulated benefit obligation		2,746		2,419
Defined Benefit Plan, Amounts Recognized in Balance Sheet
Deferred charges and other assets, net		5		2
Accrued expenses		(14)		(13)
Other long-term liabilities		(489)		(459)
Amounts recognized in balance sheet for defined benefit plans		(498)		(470)
Other Postretirement Benefit Plans [Member]
Changes in benefit obligation:
Benefit obligation at beginning of year		302	[1]	336
Service cost		6		7		8
Interest cost		10		12		14
Participant contributions		9		8
Benefits paid		(28)		(27)
Actuarial (gain) loss		6		(35)
Other		1		1
Benefit obligation at end of year		306	[1]	302	[1]	336
Changes in plan assets (a):
Fair value of plan assets at beginning of year	[1]	0		0
Actual return on plan assets	[1]	0		0
Valero contributions	[1]	19		18
Participant contributions	[1]	9		8
Benefits paid	[1]	(28)		(27)
Other	[1]	0		1
Fair value of plan assets at end of year	[1]	0		0		$ 0
Reconciliation of funded status (a):
Funded status as of end of year	[1]	(306)		(302)
Defined Benefit Plan, Amounts Recognized in Balance Sheet
Deferred charges and other assets, net		0		0
Accrued expenses		(19)		(19)
Other long-term liabilities		(287)		(283)
Amounts recognized in balance sheet for defined benefit plans		$ (306)		$ (302)
[1]	Plan assets include only the assets associated with pension plans subject to legal minimum funding standards. Plan assets associated with U.S. nonqualified pension plans are not included here because they are not protected from our creditors and therefore cannot be reflected as a reduction from our obligations under the pension plans. As a result, the reconciliation of funded status does not reflect the effect of plan assets that exist for all of our defined benefit plans. See Note 18 for the assets associated with certain U.S. nonqualified pension plans.

Employee Benefit Plans, Aggrega

Employee Benefit Plans, Aggregate Projected Benefit Obligation (Details) - Pension Plans [Member] - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Information About Pension Plans in which the Accumulated Benefit Obligation Exceeded the Fair Value of Plan Assets
Projected benefit obligation	$ 2,661	$ 2,322
Accumulated benefit obligation	2,526	2,210
Fair value of plan assets	$ 2,180	$ 1,870

Employee Benefit Plans, Benefit

Employee Benefit Plans, Benefit Payments (Details) $ in Millions	Dec. 31, 2017USD ($)
Pension Plans [Member]
Estimated Future Benefit Payments
2,018	$ 162
2,019	219
2,020	184
2,021	180
2,022	185
2023-2027	1,074
Employee Benefit Plans (Textual)
Future employer contributions to pension and other postretirement plans	131
Future employer discretionary contributions to pension plan	100
Other Postretirement Benefit Plans [Member]
Estimated Future Benefit Payments
2,018	19
2,019	19
2,020	19
2,021	19
2,022	19
2023-2027	93
Employee Benefit Plans (Textual)
Future employer contributions to pension and other postretirement plans	$ 19

Employee Benefit Plans, Compone

Employee Benefit Plans, Components of Net Periodic Benefit Cost (Credit) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Employee Benefit Plans (Textual)
The percentage of the higher of the projected benefit obligation or market-related value of plan assets in excess of which net actuarial losses are amortized	10.00%
Pension Plans [Member]
Components of net periodic benefit cost:
Service cost	$ 123	$ 111	$ 109
Interest cost	86	84	98
Expected return on plan assets	(150)	(139)	(133)
Amortization of:
Net actuarial (gain) loss	53	49	62
Prior service credit	(20)	(20)	(22)
Special charges (credits)	4	(7)	7
Net periodic benefit cost (credit)	96	78	121
Other Postretirement Benefit Plans [Member]
Components of net periodic benefit cost:
Service cost	6	7	8
Interest cost	10	12	14
Expected return on plan assets	0	0	0
Amortization of:
Net actuarial (gain) loss	(3)	(1)	0
Prior service credit	(16)	(16)	(18)
Special charges (credits)	0	0	0
Net periodic benefit cost (credit)	$ (3)	$ 2	$ 4

Employee Benefit Plans, Pre-Tax

Employee Benefit Plans, Pre-Tax Amounts Recognized in Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Net (gain) loss reclassified into income:
Total changes in other comprehensive income (loss)	$ (65)	$ (98)	$ 57
Pension Plans [Member]
Net gain (loss) arising during the year:
Net actuarial gain (loss)	(73)	(145)	24
Prior service cost	(4)	0	(22)
Net (gain) loss reclassified into income:
Net actuarial (gain) loss	53	49	62
Prior service credit	(20)	(20)	(22)
Curtailment and settlement loss	4	0	7
Total changes in other comprehensive income (loss)	(40)	(116)	49
Other Postretirement Benefit Plans [Member]
Net gain (loss) arising during the year:
Net actuarial gain (loss)	(6)	35	26
Prior service cost	0	0	0
Net (gain) loss reclassified into income:
Net actuarial (gain) loss	(3)	(1)	0
Prior service credit	(16)	(16)	(18)
Curtailment and settlement loss	0	0	0
Total changes in other comprehensive income (loss)	$ (25)	$ 18	$ 8

Employee Benefit Plans, Pre-T73

Employee Benefit Plans, Pre-Tax Amounts in Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Pension Plans [Member]
Pension and Other Postretirement Benefit Plans Accumulated Other Comprehensive Income (Loss), before Tax
Net actuarial (gain) loss	$ 894	$ 878
Prior service credit	(121)	(145)
Total	773	733
Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Benefit Plans Accumulated Other Comprehensive Income (Loss), before Tax
Net actuarial (gain) loss	(57)	(66)
Prior service credit	(42)	(58)
Total	$ (99)	$ (124)

Employee Benefit Plans, Net Per

Employee Benefit Plans, Net Periodic Benefit Costs Amortized from Accumulated Other Comprehensive Income (Loss) (Details) $ in Millions	Dec. 31, 2017USD ($)
Pension Plans [Member]
Pension and Other Postretirement Benefit Plans Amounts that Will be Amortized from Accumulated Other Comprehensive Income (Loss) in Next Fiscal Year
Amortization of net actuarial (gain) loss	$ 66
Amortization of prior service credit	(19)
Total	47
Other Postretirement Benefit Plans [Member]
Pension and Other Postretirement Benefit Plans Amounts that Will be Amortized from Accumulated Other Comprehensive Income (Loss) in Next Fiscal Year
Amortization of net actuarial (gain) loss	(2)
Amortization of prior service credit	(11)
Total	$ (13)

Employee Benefit Plans, Weighte

Employee Benefit Plans, Weighted-Average Assumptions (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Minimum [Member]
Employee Benefit Plans (Textual)
Yield curve maturities	6 months
Maximum [Member]
Employee Benefit Plans (Textual)
Yield curve maturities	99 years
Pension Plans [Member]
Weighted Average Assumptions Used to Determine Benefit Obligation
Discount rate	3.58%	4.08%
Rate of compensation increase	3.86%	3.81%
Weighted Average Assumptions Used to Determine Net Periodic Benefit Cost
Discount rate	4.08%	4.45%	4.10%
Expected long-term rate of return on plan assets	7.29%	7.28%	7.29%
Rate of compensation increase	3.81%	3.79%	3.78%
Other Postretirement Benefit Plans [Member]
Weighted Average Assumptions Used to Determine Benefit Obligation
Discount rate	3.72%	4.26%
Weighted Average Assumptions Used to Determine Net Periodic Benefit Cost
Discount rate	4.26%	4.53%	4.13%

Employee Benefit Plans, Health

Employee Benefit Plans, Health Care Cost Trend Rate (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Assumed Health Care Cost Trend Rates
Health care cost trend rate assumed for the next year	7.30%	7.28%
Rate to which the cost trend rate was assumed to decline (the ultimate trend rate)	5.00%	5.00%
Year that the rate reaches the ultimate trend rate	2,026	2,026

Employee Benefit Plans, Fair Va

Employee Benefit Plans, Fair Value of Assets Qualified Plans (Details) - USD ($) $ in Millions		Dec. 31, 2017	Dec. 31, 2016
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		$ 2,428	$ 2,097
Fair Value, Inputs, Level 1 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		1,078	1,115
Fair Value, Inputs, Level 2 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		1,350	982
Fair Value, Inputs, Level 3 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
US Companies [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets	[1]	571	562
US Companies [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets	[1]	571	562
US Companies [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets	[1]	0	0
US Companies [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets	[1]	0	0
International Companies [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		188	164
International Companies [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		187	164
International Companies [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		1	0
International Companies [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
Preferred Stock [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		4	3
Preferred Stock [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		4	3
Preferred Stock [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
Preferred Stock [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
International Growth [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		118	90
International Growth [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		118	90
International Growth [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
International Growth [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
Index Funds [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets	[2]	85	230
Index Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets	[2]	85	230
Index Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets	[2]	0	0
Index Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets	[2]	$ 0	$ 0
Index Fund - Equity Securities [Member]
Employee Benefit Plans (Textual)
Defined benefit plan, actual plan asset allocations		70.00%	50.00%
Index Fund - Debt Securities [Member]
Employee Benefit Plans (Textual)
Defined benefit plan, actual plan asset allocations		30.00%	50.00%
Corporate Debt Instruments [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		$ 272	$ 280
Corporate Debt Instruments [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
Corporate Debt Instruments [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		272	280
Corporate Debt Instruments [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
US Treasury Securities [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		45	52
US Treasury Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		45	52
US Treasury Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
US Treasury Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
Other Government Securities [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		144	158
Other Government Securities [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
Other Government Securities [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		144	158
Other Government Securities [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
Common Collective Trusts [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets	[3]	621	434
Common Collective Trusts [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets	[3]	0	0
Common Collective Trusts [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets	[3]	621	434
Common Collective Trusts [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets	[3]	$ 0	$ 0
Common Collective Trusts - Equity Securities [Member]
Employee Benefit Plans (Textual)
Defined benefit plan, actual plan asset allocations		80.00%	90.00%
Common Collective Trusts - Debt Securities [Member]
Employee Benefit Plans (Textual)
Defined benefit plan, actual plan asset allocations		20.00%	10.00%
Pooled Separate Accounts [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		$ 192
Pooled Separate Accounts [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0
Pooled Separate Accounts [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		192
Pooled Separate Accounts [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0
Private Funds [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		101	$ 76
Private Funds [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
Private Funds [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		101	76
Private Funds [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
Insurance Contract [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		18	18
Insurance Contract [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
Insurance Contract [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		18	18
Insurance Contract [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
Interest and Dividends Receivable [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		5	5
Interest and Dividends Receivable [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		5	5
Interest and Dividends Receivable [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
Interest and Dividends Receivable [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
Cash and Cash Equivalents [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		86	72
Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		85	56
Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		1	16
Cash and Cash Equivalents [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
Securities Transactions Receivable (Payable), Net [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		(22)	(47)
Securities Transactions Receivable (Payable), Net [Member] | Fair Value, Inputs, Level 1 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		(22)	(47)
Securities Transactions Receivable (Payable), Net [Member] | Fair Value, Inputs, Level 2 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		0	0
Securities Transactions Receivable (Payable), Net [Member] | Fair Value, Inputs, Level 3 [Member]
Fair Values of Qualified Pension Plan Assets
Fair value of qualified pension plan assets		$ 0	$ 0
Equity Securities [Member]
Employee Benefit Plans (Textual)
Percentage of equity securities in target allocations for plan assets		70.00%
Debt Securities [Member]
Employee Benefit Plans (Textual)
Percentage of equity securities in target allocations for plan assets		30.00%
[1]	Equity securities are held in a wide range of industrial sectors, including consumer goods, information technology, healthcare, industrials, and financial services.
[2]	This class includes primarily investments in approximately 70 percent equities and 30 percent bonds
[3]	This class includes primarily investments in approximately 80 percent equities and 20 percent bonds as of December 31, 2017. As of December 31, 2016, the class included primarily investments in approximately 90 percent equities and 10 percent bonds.

Stock-Based Compensation (Detai

Stock-Based Compensation (Details) - USD ($) $ / shares in Units, $ in Millions		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Stock-based Compensation Arrangements Activity
Stock-based compensation expense		$ 77	$ 68	$ 59
Tax benefit recognized on stock-based compensation expense		27	24	21
Tax benefit realized for tax deductions resulting from exercises and vestings		44	33	66
Effect of tax deductions in excess of recognized stock-based compensation expense (a)	[1]	24	22	44
Restricted Stock [Member]
Stock-based Compensation Arrangements Activity
Stock-based compensation expense		$ 58	$ 52	$ 47
Nonvested Shares or Awards Other Than Options Rollforward
Nonvested shares or awards, beginning balance (shares)		1,566,950
Shares or awards, granted (shares)		739,393
Shares or awards, vested (shares)		(897,246)
Shares or awards, forfeited (shares)		(8,057)
Nonvested shares or awards, ending balance (shares)		1,401,040	1,566,950
Nonvested Awards Other Than Options Weighted Average Grant Date Fair Value Rollforward
Weighted average grant date fair value, beginning balance (in dollars per share)		$ 60.68
Weighted average grant date fair value, granted (in dollars per share)		79.32	$ 59	$ 70.07
Weighted average grant date fair value, vested (in dollars per share)		61.76
Weighted average grant date fair value, forfeited (in dollars per share)		61.22
Weighted average grant date fair value, ending balance (in dollars per share)		$ 69.82	$ 60.68
Vested Awards Other Than Options Rollforward
Fair value of vested awards		$ 71	$ 46	$ 69
Stock Based Compensation (Textual)
Vesting period of stock-based payment awards granted		3 years
Unrecognized share-based compensation cost related to outstanding unvested awards		$ 61
Weighted-average period of recognition for unrecognized compensation costs on nonvested awards		2 years
Restricted Stock Awards - Nonemployee [Member]
Stock Based Compensation (Textual)
Vesting period of stock-based payment awards granted		3 years
Performance Awards [Member]
Stock-based Compensation Arrangements Activity
Stock-based compensation expense		$ 19	15	11
Employee Stock Option [Member]
Stock-based Compensation Arrangements Activity
Stock-based compensation expense		$ 0	$ 1	$ 1
Omnibus Stock Incentive Plan [Member] | Stock Compensation Plan [Member]
Stock Based Compensation (Textual)
Number of shares of common stock available to be awarded under stock-based compensation plans (shares)		9,409,188
Formerly Maintained Plans [Member] | Stock Compensation Plan [Member]
Stock Based Compensation (Textual)
Number of shares of common stock available to be awarded under stock-based compensation plans (shares)		0
[1]	Effective January 1, 2016, the effect of tax deductions in excess of recognized stock-based compensation expense is reported as an operating cash flow. These amounts were previously reported as financing cash flows.

Income Taxes, Income Statement

Income Taxes, Income Statement Components of Tax Expense (Benefit) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
U.S. operations	$ 2,283	$ 1,733	$ 5,327
International operations	924	1,449	644
Income before income tax expense (benefit)	$ 3,207	$ 3,182	$ 5,971

Income Taxes, Schedule of Statu

Income Taxes, Schedule of Statutory Tax Rates (Details)		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statutory Tax Rates
Applicable statutory income tax rate (percent)		29.80%	27.10%	32.80%
U.S. [Member]
Statutory Tax Rates
Applicable statutory income tax rate (percent)	[1]	35.00%	35.00%	35.00%
Canada [Member]
Statutory Tax Rates
Applicable statutory income tax rate (percent)		15.00%	15.00%	15.00%
U.K. [Member]
Statutory Tax Rates
Applicable statutory income tax rate (percent)		19.00%	20.25%	20.25%
Ireland [Member]
Statutory Tax Rates
Applicable statutory income tax rate (percent)		13.00%	12.50%	12.50%
Aruba [Member]
Statutory Tax Rates
Applicable statutory income tax rate (percent)	[2]		7.00%	7.00%
[1]	Statutory income tax rate was reduced to 21 percent effective January 1, 2018 as described in “Tax Reform” above.
[2]	Statutory income tax rate applicable through the date of the Aruba Disposition as described in Note 2.

Income Taxes, Reconciliation of

Income Taxes, Reconciliation of Income Tax Expense (Benefit) (Details) - USD ($) $ in Millions	3 Months Ended		12 Months Ended
	Dec. 31, 2017	Sep. 30, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Effective Income Tax Rate Reconciliation, Amount
Income tax expense at statutory rates			$ 957	$ 862	$ 1,956
U.S. state and Canadian provincial tax expense, net of federal income tax effect			83	36	118
Permanent differences:
Manufacturing deduction			(42)	(22)	(102)
Other			(9)	(13)	(23)
Change in tax law	$ (1,900)		(1,862)	(7)	(17)
Tax effects of income associated with noncontrolling interests			(31)	(44)	(39)
Other, net			(45)	(47)	(23)
Income tax expense (benefit)		$ (42)	$ (949)	$ 765	$ 1,870
Effective Income Tax Rate Reconciliation, Percent
Income tax expense at statutory rates (percent)			29.80%	27.10%	32.80%
U.S. state and Canadian provincial tax expense, net of federal income tax effect (percent)			2.60%	1.10%	2.00%
Permanent differences:
Manufacturing deduction (percent)			(1.30%)	(0.70%)	(1.70%)
Other (percent)			(0.30%)	(0.40%)	(0.40%)
Change in tax law (percent)			(58.10%)	(0.20%)	(0.30%)
Tax effects of income associated with noncontrolling interests (percent)			(1.00%)	(1.40%)	(0.70%)
Other, net (percent)			(1.40%)	(1.50%)	(0.40%)
Income tax expense (benefit) (percent)			(29.70%)	24.00%	31.30%
U.S. [Member]
Effective Income Tax Rate Reconciliation, Amount
Income tax expense at statutory rates			$ 799	$ 606	$ 1,864
U.S. state and Canadian provincial tax expense, net of federal income tax effect			37	5	45
Permanent differences:
Manufacturing deduction			(42)	(22)	(102)
Other			(9)	(3)	(18)
Change in tax law			(1,862)	0	0
Tax effects of income associated with noncontrolling interests			(31)	(44)	(39)
Other, net			(52)	(37)	(25)
Income tax expense (benefit)			$ (1,160)	$ 505	$ 1,725
Effective Income Tax Rate Reconciliation, Percent
Income tax expense at statutory rates (percent)			35.00%	35.00%	35.00%
U.S. state and Canadian provincial tax expense, net of federal income tax effect (percent)			1.60%	0.30%	0.80%
Permanent differences:
Manufacturing deduction (percent)			(1.80%)	(1.30%)	(1.90%)
Other (percent)			(0.40%)	(0.20%)	(0.30%)
Change in tax law (percent)			(81.60%)	0.00%	0.00%
Tax effects of income associated with noncontrolling interests (percent)			(1.40%)	(2.50%)	(0.70%)
Other, net (percent)			(2.30%)	(2.10%)	(0.50%)
Income tax expense (benefit) (percent)			(50.90%)	29.20%	32.40%
International [Member]
Effective Income Tax Rate Reconciliation, Amount
Income tax expense at statutory rates			$ 158	$ 256	$ 92
U.S. state and Canadian provincial tax expense, net of federal income tax effect			46	31	73
Permanent differences:
Manufacturing deduction			0	0	0
Other			0	(10)	(5)
Change in tax law			0	(7)	(17)
Tax effects of income associated with noncontrolling interests			0	0	0
Other, net			7	(10)	2
Income tax expense (benefit)			$ 211	$ 260	$ 145
Effective Income Tax Rate Reconciliation, Percent
Income tax expense at statutory rates (percent)			17.10%	17.70%	14.30%
U.S. state and Canadian provincial tax expense, net of federal income tax effect (percent)			5.00%	2.10%	11.30%
Permanent differences:
Manufacturing deduction (percent)			(0.00%)	(0.00%)	(0.00%)
Other (percent)			0.00%	(0.70%)	(0.80%)
Change in tax law (percent)			0.00%	(0.50%)	(2.60%)
Tax effects of income associated with noncontrolling interests (percent)			(0.00%)	(0.00%)	(0.00%)
Other, net (percent)			0.80%	(0.70%)	0.30%
Income tax expense (benefit) (percent)			22.90%	17.90%	22.50%

Income Taxes, Components of Inc

Income Taxes, Components of Income Tax Expense (Benefit) (Details) - USD ($) $ in Millions	3 Months Ended	12 Months Ended
	Sep. 30, 2016	Dec. 31, 2017		Dec. 31, 2016	Dec. 31, 2015
Current:
Country		$ 1,499		$ 488	$ 1,577
U.S. state / Canadian provincial		95		47	128
Total current		1,594		535	1,705
Deferred:
Country		(2,551)		238	151
U.S. state / Canadian provincial		8		(8)	14
Total deferred		(2,543)		230	165
Income tax expense (benefit)	$ (42)	(949)		765	1,870
Deferred income tax benefit included in tax reform		2,643
U.S. [Member]
Current:
Country		1,305		294	1,513
U.S. state / Canadian provincial		34		12	85
Total current		1,339	[1]	306	1,598
Deferred:
Country		(2,522)		203	143
U.S. state / Canadian provincial		23		(4)	(16)
Total deferred		(2,499)	[2]	199	127
Income tax expense (benefit)		(1,160)		505	1,725
Current income tax expense included in tax reform adjustment		781
Deferred income tax benefit included in tax reform		2,600
International [Member]
Current:
Country		194		194	64
U.S. state / Canadian provincial		61		35	43
Total current		255		229	107
Deferred:
Country		(29)		35	8
U.S. state / Canadian provincial		(15)		(4)	30
Total deferred		(44)		31	38
Income tax expense (benefit)		$ 211		$ 260	$ 145
[1]	Current income tax expense includes the effect of our $781 million Tax Reform adjustment as described in “Tax Reform” above.
[2]	Deferred income tax benefit includes the effect of our $2.6 billion Tax Reform adjustment as described in “Tax Reform” above.

Income Taxes, Schedule of Incom

Income Taxes, Schedule of Income Taxes Paid (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Taxes Paid, Net
Income taxes paid, net	$ 410	$ 444	$ 2,093
U.S. [Member]
Income Taxes Paid, Net
Income taxes paid, net	239	241	2,092
International [Member]
Income Taxes Paid, Net
Income taxes paid, net	$ 171	$ 203	$ 1

Income Taxes, Deferred Income T

Income Taxes, Deferred Income Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Deferred income tax assets:
Tax credit carryforwards	$ 69	$ 65
Net operating losses (NOLs)	492	374
Inventories	135	93
Compensation and employee benefit liabilities	179	344
Environmental liabilities	47	69
Other	112	100
Total deferred income tax assets	1,034	1,045
Valuation allowance	(498)	(374)
Net deferred income tax assets	536	671
Deferred income tax liabilities:
Property, plant, and equipment	4,545	6,900
Deferred turnaround costs	272	450
Inventories	243	356
Investments	77	253
Other	107	73
Total deferred income tax liabilities	5,244	8,032
Net deferred income tax liabilities	$ 4,708	$ 7,361

Income Taxes, Tax Credits and L

Income Taxes, Tax Credits and Loss Carryforwards (Details) - U.S. state income tax credits [Member] $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)
Operating Loss Carryforwards
U.S. state NOLs (gross amount)	$ 9,441
U S State Income Tax Credits Limited [Member]
Operating Loss Carryforwards
U.S. state income tax credits	76
U S State Income Tax Credits Unlimited [Member]
Operating Loss Carryforwards
U.S. state income tax credits	$ 11
Minimum [Member]
Operating Loss Carryforwards
U.S state NOL (gross amount)	Dec. 31, 2018
Minimum [Member] | U S State Income Tax Credits Limited [Member]
Operating Loss Carryforwards
U.S state income tax credits	Dec. 31, 2018
Maximum [Member]
Operating Loss Carryforwards
U.S state NOL (gross amount)	Dec. 31, 2037
Maximum [Member] | U S State Income Tax Credits Limited [Member]
Operating Loss Carryforwards
U.S state income tax credits	Dec. 31, 2031

Income Taxes, Details of the Ta

Income Taxes, Details of the Tax Reform Adjustment (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)
Income Tax Disclosure [Abstract]
Income tax benefit from the remeasurement of U.S. deferred income tax assets and liabilities	$ (2,643)
Tax on the deemed repatriation of the accumulated earnings and profits of our international subsidiaries	734
Recognition of foreign withholding tax, net of U.S. federal tax benefit	47
Deductibility of certain executive compensation expense	0
Income tax expense associated with the statutory income tax rate differential on accrual to return adjustments that may be identified upon completion of our U.S. federal income tax return in 2018	0
Foreign tax credit available to offset the tax on deemed repatriation of the accumulated earnings and profits of our international subsidiaries	0
Estimated Tax Reform benefit	$ (1,862)

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
Unrecognized Tax Benefits [Roll Forward]
Balance as of beginning of year	$ 936	$ 964	$ 989
Additions based on tax positions related to the current year	33	36	36
Additions for tax positions related to prior years	15	11	83
Reductions for tax positions related to prior years	(42)	(46)	(82)
Reductions for tax positions related to the lapse of applicable statute of limitations	(1)	(3)	(3)
Settlements	0	(237)	(59)
Reclassification of uncertain tax receivable to long-term receivable from IRS	0	211	0
Balance as of end of year	$ 941	$ 936	$ 964

Income Taxes, Reconciliation 88

Income Taxes, Reconciliation of Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Unrecognized tax benefits	$ 941	$ 936	$ 964	$ 989
Tax refund claim not presented in our balance sheets	(274)	(433)
Other	77	(5)
Uncertain tax position liabilities presented in our balance sheets	$ 744	$ 498

Income Taxes, Unrecognized Ta89

Income Taxes, Unrecognized Tax Benefits Recognized in Balance Sheet (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Amounts Recognized in Balance Sheets for Uncertain Tax Positions
Other long-term liabilities and Deferred tax liabilities	$ (723)	$ (465)
Uncertain tax position liabilities presented in our balance sheets	(744)	(498)
Income Taxes Payable [Member]
Amounts Recognized in Balance Sheets for Uncertain Tax Positions
Income taxes payable	0	(7)
Other Noncurrent Liabilities [Member]
Amounts Recognized in Balance Sheets for Uncertain Tax Positions
Other long-term liabilities and Deferred tax liabilities	(723)	(465)
Deferred Income Taxes [Member]
Amounts Recognized in Balance Sheets for Uncertain Tax Positions
Other long-term liabilities and Deferred tax liabilities	$ (21)	$ (26)

Income Taxes, Narrative (Detail

Income Taxes, Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Income Tax Narrative
Income tax benefit resulting from effect of tax reform adjustments	$ 1,862
Income tax benefit from the remeasurement of U.S. deferred income tax assets and liabilities	2,643
Tax on the deemed repatriation of the accumulated earnings and profits of our international subsidiaries	734
Cumulative undistributed earnings and profits of international subsidiaries	4,700
Recognition of foreign withholding tax, net of U.S. federal tax benefit	47
Increase in valuation allowance	124
Cash and temporary cash investments	5,850	$ 4,816	$ 4,114	$ 3,689
Tax refund claim not presented in our balance sheets	274	433
Income tax benefits if recognized that would impact the effective tax rate	793	756
Interest expense and penalties accrued	77	$ 70
International subsidiaries [Member]
Income Tax Narrative
Cash and temporary cash investments	$ 3,200

Earnings Per Common Share (Deta

Earnings Per Common Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Less dividends paid:
Weighted-average common shares outstanding (in millions) (shares)	442	461	497
Earnings per common share – assuming dilution:
Weighted-average common shares outstanding (in millions) (shares)	442	461	497
Weighted-average common shares outstanding – assuming dilution (in millions) (shares)	444	464	500
Common Class A [Member]
Earnings per common share from continuing operations:
Net income attributable to Valero stockholders	$ 4,065	$ 2,289	$ 3,990
Less dividends paid:
Common stock	1,238	1,108	845
Participating securities	4	3	3
Undistributed earnings	$ 2,823	$ 1,178	$ 3,142
Weighted-average common shares outstanding (in millions) (shares)	442	461	497
Earnings per common share:
Distributed earnings (in usd per share)	$ 2.80	$ 2.40	$ 1.70
Undistributed earnings (in usd per share)	6.37	2.54	6.30
Total earnings per common share (in usd per share)	$ 9.17	$ 4.94	$ 8
Earnings per common share – assuming dilution:
Net income attributable to Valero stockholders	$ 4,065	$ 2,289	$ 3,990
Weighted-average common shares outstanding (in millions) (shares)	442	461	497
Weighted-average common equivalent shares outstanding (in millions) (shares)	2	3	3
Weighted-average common shares outstanding – assuming dilution (in millions) (shares)	444	464	500
Earnings per common share – assuming dilution (in usd per share)	$ 9.16	$ 4.94	$ 7.99
Participating Securities [Member]
Less dividends paid:
Weighted-average common shares outstanding (in millions) (shares)	2	1	2
Earnings per common share:
Distributed earnings (in usd per share)	$ 2.80	$ 2.40	$ 1.70
Undistributed earnings (in usd per share)	6.37	2.54	6.30
Total earnings per common share (in usd per share)	$ 9.17	$ 4.94	$ 8
Earnings per common share – assuming dilution:
Weighted-average common shares outstanding (in millions) (shares)	2	1	2

Segment Information, Activity (

Segment Information, Activity (Details) $ in Millions	3 Months Ended												12 Months Ended
	Dec. 31, 2017USD ($)	[1]	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Sep. 30, 2016USD ($)	[2]	Jun. 30, 2016USD ($)		Mar. 31, 2016USD ($)		Dec. 31, 2017USD ($)segment		Dec. 31, 2016USD ($)		Dec. 31, 2015USD ($)
Segment Information for our Reportable Segments
Operating revenues	$ 26,392		$ 23,562	$ 22,254	$ 21,772	$ 20,712	$ 19,649		$ 19,584	[3]	$ 15,714	[4]	$ 93,980	[5]	$ 75,659	[5]	$ 87,804	[5]
Cost of materials and other													83,037		65,962		73,861
Operating expenses (excluding depreciation and amortization expense reflected below)													4,462		4,207		4,243
Depreciation and amortization expense													1,934		1,846		1,795
Lower of cost or market inventory valuation adjustment									(454)		(293)		0		(747)		790
Total cost of sales													89,433		71,268		80,689
Other operating expenses													61		0		0
General and administrative expenses (excluding depreciation and amortization expense reflected below)													835		715		710
Depreciation and amortization expense													52		48		47
Asset impairment loss									56				0		56		0
Operating income by segment	$ 853		$ 1,338	$ 871	$ 537	$ 620	$ 892		$ 1,231	[3]	$ 829	[4]	3,599		3,572		6,358
Total expenditures for long-lived assets													$ 1,948		1,996		2,350
Segment Information (Textual)
Number of reportable segments | segment													3
Corporate, Reconciling Items, and Eliminations[Member]
Segment Information for our Reportable Segments
Operating revenues													$ (629)		(573)		(395)
Operating income by segment													(882)		(763)		(757)
Corporate [Member]
Segment Information for our Reportable Segments
Operating revenues													5		0		0
General and administrative expenses (excluding depreciation and amortization expense reflected below)													835		715		710
Depreciation and amortization expense													52		48		47
Asset impairment loss															0
Total expenditures for long-lived assets													44		38		29
Intersegment Eliminations [Member]
Segment Information for our Reportable Segments
Operating revenues													(634)		(573)		(395)
Cost of materials and other													(632)		(573)		(395)
Operating expenses (excluding depreciation and amortization expense reflected below)													(2)		0		0
Depreciation and amortization expense													0		0		0
Total cost of sales													(634)		(573)		(395)
Other operating expenses													0
Refining [Member]
Segment Information for our Reportable Segments
Operating revenues													90,651		71,968		84,521
Refining [Member] | Operating Segments [Member]
Segment Information for our Reportable Segments
Operating revenues													90,657		71,968		84,521
Cost of materials and other													80,865		63,405		71,512
Operating expenses (excluding depreciation and amortization expense reflected below)													3,917		3,696		3,689
Depreciation and amortization expense													1,800		1,734		1,699
Lower of cost or market inventory valuation adjustment															(697)		740
Total cost of sales													86,582		68,138		77,640
Other operating expenses													58
General and administrative expenses (excluding depreciation and amortization expense reflected below)													0		0		0
Depreciation and amortization expense													0		0		0
Asset impairment loss															56
Operating income by segment													4,017		3,774		6,881
Total expenditures for long-lived assets													1,710		1,867		2,216
Refining [Member] | Intersegment Eliminations [Member]
Segment Information for our Reportable Segments
Operating revenues													6		0		0
Ethanol [Member]
Segment Information for our Reportable Segments
Operating revenues													3,324		3,691		3,283
Ethanol [Member] | Operating Segments [Member]
Segment Information for our Reportable Segments
Operating revenues													3,500		3,901		3,434
Cost of materials and other													2,804		3,130		2,744
Operating expenses (excluding depreciation and amortization expense reflected below)													443		415		448
Depreciation and amortization expense													81		66		50
Lower of cost or market inventory valuation adjustment															(50)		50
Total cost of sales													3,328		3,561		3,292
Other operating expenses													0
General and administrative expenses (excluding depreciation and amortization expense reflected below)													0		0		0
Depreciation and amortization expense													0		0		0
Asset impairment loss															0
Operating income by segment													172		340		142
Total expenditures for long-lived assets													84		68		67
Ethanol [Member] | Intersegment Eliminations [Member]
Segment Information for our Reportable Segments
Operating revenues													176		210		151
VLP [Member]
Segment Information for our Reportable Segments
Operating revenues													0		0		0
VLP [Member] | Operating Segments [Member]
Segment Information for our Reportable Segments
Operating revenues													452		363		244
Cost of materials and other													0		0		0
Operating expenses (excluding depreciation and amortization expense reflected below)													104		96		106
Depreciation and amortization expense													53		46		46
Lower of cost or market inventory valuation adjustment															0		0
Total cost of sales													157		142		152
Other operating expenses													3
General and administrative expenses (excluding depreciation and amortization expense reflected below)													0		0		0
Depreciation and amortization expense													0		0		0
Asset impairment loss															0
Operating income by segment													292		221		92
Total expenditures for long-lived assets													110		23		38
VLP [Member] | Intersegment Eliminations [Member]
Segment Information for our Reportable Segments
Operating revenues													$ 452		$ 363		$ 244
[1]	During the quarter ended December 31, 2017, we recognized an income tax benefit of $1.9 billion related to Tax Reform as described in Note 14.
[2]	During the quarter ended September 30, 2016, we recognized a tax benefit of $42 million related to the Aruba Disposition as described in Note 2.
[3]	During the quarter ended June 30, 2016, we recognized a favorable noncash lower of cost or market inventory valuation adjustment of $454 million as described in Note 4 and an asset impairment loss of $56 million related to the Aruba Disposition as described in Note 2.
[4]	During the quarter ended March 31, 2016, we recognized a favorable noncash lower of cost or market inventory valuation adjustment of $293 million as described in Note 4.
[5]	Includes excise taxes on sales by certain of our international operations of $5,573 million, $5,493 million, and $5,980 million for the years ended December 31, 2017, 2016, and 2015.

Segment Information, Revenue by

Segment Information, Revenue by Product (Details) - USD ($) $ in Millions

3 Months Ended

12 Months Ended

Dec. 31, 2017

[1]

Sep. 30, 2017

Jun. 30, 2017

Mar. 31, 2017

Dec. 31, 2016

Sep. 30, 2016

[2]

Jun. 30, 2016

[3]

Mar. 31, 2016

[4]

Dec. 31, 2017

Dec. 31, 2016

Dec. 31, 2015

Revenue from External Customer [Line Items]

Operating revenues

$ 26,392

$ 23,562

$ 22,254

$ 21,772

$ 20,712

$ 19,649

$ 19,584

$ 15,714

$ 93,980

[5]

$ 75,659

[5]

$ 87,804

[5]

Corporate [Member]

Revenue from External Customer [Line Items]

Operating revenues

5

0

0

Other Revenues [Member] | Corporate [Member]

Revenue from External Customer [Line Items]

Operating revenues

5

0

0

Refining [Member]

Revenue from External Customer [Line Items]

Operating revenues

90,651

71,968

84,521

Refining [Member] | Gasoline and Blendstocks [Member]

Revenue from External Customer [Line Items]

Operating revenues

40,362

33,450

38,983

Refining [Member] | Distillates [Member]

Revenue from External Customer [Line Items]

Operating revenues

42,074

32,576

38,093

Refining [Member] | Other Product Revenues [Member]

Revenue from External Customer [Line Items]

Operating revenues

8,215

5,942

7,445

Ethanol [Member]

Revenue from External Customer [Line Items]

Operating revenues

3,324

3,691

3,283

Ethanol [Member] | Ethanol [Member]

Revenue from External Customer [Line Items]

Operating revenues

2,764

3,105

2,628

Ethanol [Member] | Distillers Grains [Member]

Revenue from External Customer [Line Items]

Operating revenues

$ 560

$ 586

$ 655

[1]

During the quarter ended December 31, 2017, we recognized an income tax benefit of $1.9 billion related to Tax Reform as described in Note 14.

[2]

During the quarter ended September 30, 2016, we recognized a tax benefit of $42 million related to the Aruba Disposition as described in Note 2.

[3]

During the quarter ended June 30, 2016, we recognized a favorable noncash lower of cost or market inventory valuation adjustment of $454 million as described in Note 4 and an asset impairment loss of $56 million related to the Aruba Disposition as described in Note 2.

[4]

During the quarter ended March 31, 2016, we recognized a favorable noncash lower of cost or market inventory valuation adjustment of $293 million as described in Note 4.

[5]

Includes excise taxes on sales by certain of our international operations of $5,573 million, $5,493 million, and $5,980 million for the years ended December 31, 2017, 2016, and 2015.

Segment Information, Geographic

Segment Information, Geographic Information by Country for Revenue and Long-Lived Assets (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	[2]	Jun. 30, 2016	[3]	Mar. 31, 2016	[4]	Dec. 31, 2017		Dec. 31, 2016		Dec. 31, 2015
Operating Revenues by Geographic Area
Operating revenues	$ 26,392	[1]	$ 23,562	$ 22,254	$ 21,772	$ 20,712	$ 19,649		$ 19,584		$ 15,714		$ 93,980	[5]	$ 75,659	[5]	$ 87,804	[5]
Geographic Information by Country for Long-Lived Assets
Long-lived assets	29,061					28,142							29,061		28,142
U.S. [Member]
Operating Revenues by Geographic Area
Operating revenues													66,614		51,479		60,319
Geographic Information by Country for Long-Lived Assets
Long-lived assets	26,083					25,359							26,083		25,359
Canada [Member]
Operating Revenues by Geographic Area
Operating revenues													7,039		6,115		6,841
Geographic Information by Country for Long-Lived Assets
Long-lived assets	1,915					1,816							1,915		1,816
U.K.and Ireland [Member]
Operating Revenues by Geographic Area
Operating revenues													11,556		10,797		11,232
Geographic Information by Country for Long-Lived Assets
Long-lived assets	$ 1,063					$ 967							1,063		967
Other Countries [Member]
Operating Revenues by Geographic Area
Operating revenues													$ 8,771		$ 7,268		$ 9,412
[1]	During the quarter ended December 31, 2017, we recognized an income tax benefit of $1.9 billion related to Tax Reform as described in Note 14.
[2]	During the quarter ended September 30, 2016, we recognized a tax benefit of $42 million related to the Aruba Disposition as described in Note 2.
[3]	During the quarter ended June 30, 2016, we recognized a favorable noncash lower of cost or market inventory valuation adjustment of $454 million as described in Note 4 and an asset impairment loss of $56 million related to the Aruba Disposition as described in Note 2.
[4]	During the quarter ended March 31, 2016, we recognized a favorable noncash lower of cost or market inventory valuation adjustment of $293 million as described in Note 4.
[5]	Includes excise taxes on sales by certain of our international operations of $5,573 million, $5,493 million, and $5,980 million for the years ended December 31, 2017, 2016, and 2015.

Segment Information, Total Asse

Segment Information, Total Assets by Reportable Segments (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Total Assets by Reportable Segments
Reportable segment assets	$ 50,158	$ 46,173
Operating Segments [Member] | Refining [Member]
Total Assets by Reportable Segments
Reportable segment assets	40,382	38,095
Operating Segments [Member] | Ethanol [Member]
Total Assets by Reportable Segments
Reportable segment assets	1,344	1,316
Operating Segments [Member] | VLP [Member]
Total Assets by Reportable Segments
Reportable segment assets	1,517	979
Corporate and Eliminations [Member]
Total Assets by Reportable Segments
Reportable segment assets	$ 6,915	$ 5,783

Supplemental Cash Flow Inform96

Supplemental Cash Flow Information (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Decrease (increase) in current assets:
Receivables, net	$ (870)	$ (1,531)	$ 1,294
Inventories	(516)	771	(222)
Prepaid expenses and other	151	47	(149)
Increase (decrease) in current liabilities:
Accounts payable	1,842	1,556	(1,787)
Accrued expenses	21	117	(40)
Taxes other than income taxes payable	172	82	(74)
Income taxes payable	489	(66)	(328)
Changes in current assets and current liabilities	1,289	976	(1,306)
Cash Flows Related to Interest and Income Taxes
Interest paid in excess of amount capitalized	457	427	416
Income taxes paid, net	410	444	2,093
Supplemental Cash Flow Elements (Textual)
Payment of long-term liability to joint venture partner	$ 26	194	$ (25)
Owner-Method Joint Venture Investment [Member]
Supplemental Cash Flow Elements (Textual)
Payment of long-term liability to joint venture partner		$ 137

Fair Value Measurements, Recurr

Fair Value Measurements, Recurring (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Assets:
Investments of certain benefit plans	$ 2,428	$ 2,097
Fair Value, Inputs, Level 1 [Member]
Assets:
Investments of certain benefit plans	1,078	1,115
Fair Value, Inputs, Level 2 [Member]
Assets:
Investments of certain benefit plans	1,350	982
Fair Value, Inputs, Level 3 [Member]
Assets:
Investments of certain benefit plans	0	0
Fair Value, Measurements, Recurring [Member]
Assets:
Investments of certain benefit plans	73	69
Total gross fair value, assets	967	984
Effect of Counter- party Netting	(893)	(875)
Effect of Cash Collateral Netting	0	0
Net Carrying Value on Balance Sheet, Assets	74	109
Liabilities:
Environmental credit obligations	104	188
Total gross fair value, liabilities	1,086	1,088
Effect of Counter- party Netting	(893)	(875)
Effect of Cash Collateral Netting	(76)	(20)
Net Carrying Value on Balance Sheet, Liabilities	117	193
Fair Value, Measurements, Recurring [Member] | Commodity Derivative Contracts [Member]
Assets:
Derivative contracts	894	912
Effect of Counter- party Netting	(893)	(875)
Effect of Cash Collateral Netting	0	0
Derivative contracts, net assets	1	37
Cash Collateral Received Not Offset	0	0
Liabilities:
Derivative contracts	969	895
Effect of Counter- party Netting	(893)	(875)
Effect of Cash Collateral Netting	(76)	(20)
Derivative contracts, net liabilities	0	0
Cash Collateral Paid Not Offset	(102)	(88)
Fair Value, Measurements, Recurring [Member] | Physical Purchase Contracts [Member]
Liabilities:
Derivative contracts	6	5
Derivative contracts, net liabilities	6	5
Fair Value, Measurements, Recurring [Member] | Foreign Currency Contracts [Member]
Assets:
Derivative contracts		3
Derivative contracts, net assets		3
Liabilities:
Derivative contracts	7
Derivative contracts, net liabilities	7
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member]
Assets:
Investments of certain benefit plans	65	58
Total gross fair value, assets	940	935
Liabilities:
Environmental credit obligations	0	0
Total gross fair value, liabilities	962	872
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Commodity Derivative Contracts [Member]
Assets:
Derivative contracts	875	874
Liabilities:
Derivative contracts	955	872
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Physical Purchase Contracts [Member]
Liabilities:
Derivative contracts	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | Foreign Currency Contracts [Member]
Assets:
Derivative contracts		3
Liabilities:
Derivative contracts	7
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member]
Assets:
Investments of certain benefit plans	0	0
Total gross fair value, assets	19	38
Liabilities:
Environmental credit obligations	104	188
Total gross fair value, liabilities	124	216
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Commodity Derivative Contracts [Member]
Assets:
Derivative contracts	19	38
Liabilities:
Derivative contracts	14	23
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Physical Purchase Contracts [Member]
Liabilities:
Derivative contracts	6	5
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 2 [Member] | Foreign Currency Contracts [Member]
Assets:
Derivative contracts		0
Liabilities:
Derivative contracts	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member]
Assets:
Investments of certain benefit plans	8	11
Total gross fair value, assets	8	11
Liabilities:
Environmental credit obligations	0	0
Total gross fair value, liabilities	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Commodity Derivative Contracts [Member]
Assets:
Derivative contracts	0	0
Liabilities:
Derivative contracts	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Physical Purchase Contracts [Member]
Liabilities:
Derivative contracts	0	0
Fair Value, Measurements, Recurring [Member] | Fair Value, Inputs, Level 3 [Member] | Foreign Currency Contracts [Member]
Assets:
Derivative contracts		$ 0
Liabilities:
Derivative contracts	$ 0

Fair Value Measurements, Nonrec

Fair Value Measurements, Nonrecurring (Details) - USD ($)	1 Months Ended	3 Months Ended	12 Months Ended
	Jun. 30, 2016	Jun. 30, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Fair Value Measurements (Textual)
Asset impairment loss		$ 56,000,000	$ 0	$ 56,000,000	$ 0
Fair Value, Measurements, Nonrecurring [Member]
Fair Value Measurements (Textual)
Assets measured at fair value, nonrecurring			0	0
Liabilities measured at fair value, nonrecurring			$ 0	$ 0
Aruba Terminal [Member]
Fair Value Measurements (Textual)
Asset impairment loss	$ 56,000,000

Fair Value Measurements, Other

Fair Value Measurements, Other Financial Instruments (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Financial assets:
Cash and temporary cash investments, at carrying amount	$ 5,850	$ 4,816	$ 4,114	$ 3,689
Financial liabilities:
Debt (excluding capital leases), at carrying amount	8,310	7,926
Fair Value, Inputs, Level 1 [Member]
Financial assets:
Cash and temporary cash investments, at fair value	5,850	4,816
Fair Value, Inputs, Level 2 [Member]
Financial liabilities:
Debt (excluding capital leases), at fair value	$ 9,795	$ 8,882

Price Risk Management Activi100

Price Risk Management Activities (Details) lb in Thousands, bu in Thousands, $ in Millions	12 Months Ended
	Dec. 31, 2017USD ($)lbMBblsbu	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Price Risk Management Activities (Textual)
Compliance program costs | $	$ 942	$ 749	$ 440
Foreign Currency Contracts [Member]
Price Risk Management Activities (Textual)
Monetary notional amount of derivative liabilities | $	$ 507
Foreign currency commitments maturity date	Jan. 31, 2018
Not Designated as Hedging Instrument, Economic Hedge [Member] | Swap, 2018 Maturity [Member] | Long (Purchases) [Member] | Crude Oil (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume	2,655
Not Designated as Hedging Instrument, Economic Hedge [Member] | Swap, 2018 Maturity [Member] | Short (Sales) [Member] | Crude Oil (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume	2,590
Not Designated as Hedging Instrument, Economic Hedge [Member] | Swap, 2019 Maturity [Member] | Long (Purchases) [Member] | Crude Oil (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume	0
Not Designated as Hedging Instrument, Economic Hedge [Member] | Swap, 2019 Maturity [Member] | Short (Sales) [Member] | Crude Oil (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume	0
Not Designated as Hedging Instrument, Economic Hedge [Member] | Future, 2018 Maturity [Member] | Long (Purchases) [Member] | Crude Oil (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume	83,296
Not Designated as Hedging Instrument, Economic Hedge [Member] | Future, 2018 Maturity [Member] | Long (Purchases) [Member] | Grain (in bushels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume | bu	21,315
Not Designated as Hedging Instrument, Economic Hedge [Member] | Future, 2018 Maturity [Member] | Long (Purchases) [Member] | Soybean Oil (in pounds) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, mass | lb	76,079
Not Designated as Hedging Instrument, Economic Hedge [Member] | Future, 2018 Maturity [Member] | Short (Sales) [Member] | Crude Oil (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume	87,542
Not Designated as Hedging Instrument, Economic Hedge [Member] | Future, 2018 Maturity [Member] | Short (Sales) [Member] | Grain (in bushels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume | bu	50,695
Not Designated as Hedging Instrument, Economic Hedge [Member] | Future, 2018 Maturity [Member] | Short (Sales) [Member] | Soybean Oil (in pounds) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, mass | lb	154,378
Not Designated as Hedging Instrument, Economic Hedge [Member] | Future, 2019 Maturity [Member] | Long (Purchases) [Member] | Crude Oil (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume	0
Not Designated as Hedging Instrument, Economic Hedge [Member] | Future, 2019 Maturity [Member] | Long (Purchases) [Member] | Grain (in bushels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume | bu	35
Not Designated as Hedging Instrument, Economic Hedge [Member] | Future, 2019 Maturity [Member] | Long (Purchases) [Member] | Soybean Oil (in pounds) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, mass | lb	0
Not Designated as Hedging Instrument, Economic Hedge [Member] | Future, 2019 Maturity [Member] | Short (Sales) [Member] | Crude Oil (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume	0
Not Designated as Hedging Instrument, Economic Hedge [Member] | Future, 2019 Maturity [Member] | Short (Sales) [Member] | Grain (in bushels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume | bu	665
Not Designated as Hedging Instrument, Economic Hedge [Member] | Future, 2019 Maturity [Member] | Short (Sales) [Member] | Soybean Oil (in pounds) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, mass | lb	0
Not Designated as Hedging Instrument, Economic Hedge [Member] | Forward Contracts, 2018 Maturity [Member] | Long (Purchases) [Member] | Grain (in bushels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume | bu	25,103
Not Designated as Hedging Instrument, Economic Hedge [Member] | Forward Contracts, 2019 Maturity [Member] | Long (Purchases) [Member] | Grain (in bushels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume | bu	630
Not Designated as Hedging Instrument, Trading [Member] | Swap, 2018 Maturity [Member] | Long (Purchases) [Member] | Crude Oil (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume	659
Not Designated as Hedging Instrument, Trading [Member] | Swap, 2018 Maturity [Member] | Short (Sales) [Member] | Crude Oil (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume	659
Not Designated as Hedging Instrument, Trading [Member] | Swap, 2019 Maturity [Member] | Long (Purchases) [Member] | Crude Oil (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume	0
Not Designated as Hedging Instrument, Trading [Member] | Swap, 2019 Maturity [Member] | Short (Sales) [Member] | Crude Oil (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume	0
Not Designated as Hedging Instrument, Trading [Member] | Future, 2018 Maturity [Member] | Long (Purchases) [Member] | Crude Oil (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume	37,532
Not Designated as Hedging Instrument, Trading [Member] | Future, 2018 Maturity [Member] | Long (Purchases) [Member] | Grain (in bushels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume | bu	300
Not Designated as Hedging Instrument, Trading [Member] | Future, 2018 Maturity [Member] | Short (Sales) [Member] | Crude Oil (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume	36,919
Not Designated as Hedging Instrument, Trading [Member] | Future, 2019 Maturity [Member] | Long (Purchases) [Member] | Crude Oil (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume	0
Not Designated as Hedging Instrument, Trading [Member] | Future, 2019 Maturity [Member] | Long (Purchases) [Member] | Grain (in bushels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume | bu	0
Not Designated as Hedging Instrument, Trading [Member] | Future, 2019 Maturity [Member] | Short (Sales) [Member] | Crude Oil (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume	150
Not Designated as Hedging Instrument, Trading [Member] | Options Held, 2018 Maturity [Member] | Long (Purchases) [Member] | Crude Oil (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume	153,050
Not Designated as Hedging Instrument, Trading [Member] | Options Held, 2018 Maturity [Member] | Short (Sales) [Member] | Crude Oil (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume	153,050
Not Designated as Hedging Instrument, Trading [Member] | Options Held, 2019 Maturity [Member] | Long (Purchases) [Member] | Crude Oil (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume	0
Not Designated as Hedging Instrument, Trading [Member] | Options Held, 2019 Maturity [Member] | Short (Sales) [Member] | Crude Oil (in thousands of barrels) [Member]
Volume of Outstanding Contracts
Nonmonetary notional amount of price risk derivatives, volume	0

Price Risk Management Activi101

Price Risk Management Activities, Hedging Instruments by Consolidated Balance Sheet Location (Details) - Not Designated as Hedging Instrument [Member] - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Fair Values of Derivative Instruments
Derivative asset, fair value, gross asset	$ 894	$ 915
Derivative liability, fair value, gross liability	982	900
Commodity Future [Member] | Trade Accounts Receivable [Member]
Fair Values of Derivative Instruments
Derivative asset, fair value, gross asset	875	874
Derivative asset, fair value, gross liability	955	872
Commodity Swap [Member] | Trade Accounts Receivable [Member]
Fair Values of Derivative Instruments
Derivative asset, fair value, gross asset	11	32
Derivative asset, fair value, gross liability	11	21
Commodity Option [Member] | Trade Accounts Receivable [Member]
Fair Values of Derivative Instruments
Derivative asset, fair value, gross asset	8	6
Derivative asset, fair value, gross liability	3	2
Physical Purchase Contracts [Member] | Inventories [Member]
Fair Values of Derivative Instruments
Derivative asset, fair value, gross asset	0	0
Derivative asset, fair value, gross liability	6	5
Foreign Currency Contracts [Member] | Trade Accounts Receivable [Member]
Fair Values of Derivative Instruments
Derivative asset, fair value, gross asset		3
Derivative asset, fair value, gross liability		$ 0
Foreign Currency Contracts [Member] | Accrued Liabilities [Member]
Fair Values of Derivative Instruments
Derivative liability, fair value, gross asset	0
Derivative liability, fair value, gross liability	$ 7

Price Risk Management Activi102

Price Risk Management Activities, Gain (Loss) by Income Statement Location (Details) - Cost of Sales [Member] - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Economic Hedging [Member] | Commodity Contract [Member]
Effect of Derivative Instruments on Income and OCI
Gain (loss) recognized in income on derivatives	$ (344)	$ (132)	$ 377
Economic Hedging [Member] | Foreign Currency Contracts [Member]
Effect of Derivative Instruments on Income and OCI
Gain (loss) recognized in income on derivatives	(40)	16	49
Trading Derivatives [Member] | Commodity Contract [Member]
Effect of Derivative Instruments on Income and OCI
Gain (loss) recognized in income on derivatives	$ 66	$ 46	$ 45

Quarterly Financial Data (Un103

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
Quarterly Financial Data
Operating revenues		$ 26,392	[1]	$ 23,562	$ 22,254	$ 21,772	$ 20,712	$ 19,649	[2]	$ 19,584	[3]	$ 15,714	[4]	$ 93,980	[5]	$ 75,659	[5]	$ 87,804	[5]
Gross profit	[6]	1,121	[1]	1,624	1,063	739	841	1,096	[2]	1,457	[3]	997	[4]
Operating income		853	[1]	1,338	871	537	620	892	[2]	1,231	[3]	829	[4]	3,599		3,572		6,358
Net income		2,400	[1]	863	572	321	416	645	[2]	843	[3]	513	[4]	4,156		2,417		4,101
Net income attributable to Valero Energy Corporation stockholders		$ 2,371	[1]	$ 841	$ 548	$ 305	$ 367	$ 613	[2]	$ 814	[3]	$ 495	[4]	$ 4,065		$ 2,289		$ 3,990
Earnings per common share (in usd per share)		$ 5.43	[1]	$ 1.91	$ 1.23	$ 0.68	$ 0.81	$ 1.33	[2]	$ 1.74	[3]	$ 1.05	[4]	$ 9.17		$ 4.94		$ 8
Earnings per common share - assuming dilution (in usd per share)		$ 5.42	[1]	$ 1.91	$ 1.23	$ 0.68	$ 0.81	$ 1.33	[2]	$ 1.73	[3]	$ 1.05	[4]	$ 9.16		$ 4.94		$ 7.99
Quarterly Financial Data (Textual)
Income tax benefit related to Tax Reform		$ 1,900												$ 1,862		$ 7		$ 17
Lower of cost or market inventory valuation adjustment										$ (454)		$ (293)		0		(747)		790
Asset impairment loss										$ 56				0		56		0
Tax benefit on disposition								$ 42						$ 949		$ (765)		$ (1,870)
[1]	During the quarter ended December 31, 2017, we recognized an income tax benefit of $1.9 billion related to Tax Reform as described in Note 14.
[2]	During the quarter ended September 30, 2016, we recognized a tax benefit of $42 million related to the Aruba Disposition as described in Note 2.
[3]	During the quarter ended June 30, 2016, we recognized a favorable noncash lower of cost or market inventory valuation adjustment of $454 million as described in Note 4 and an asset impairment loss of $56 million related to the Aruba Disposition as described in Note 2.
[4]	During the quarter ended March 31, 2016, we recognized a favorable noncash lower of cost or market inventory valuation adjustment of $293 million as described in Note 4.
[5]	Includes excise taxes on sales by certain of our international operations of $5,573 million, $5,493 million, and $5,980 million for the years ended December 31, 2017, 2016, and 2015.
[6]	Gross profit is calculated as operating revenues less total cost of sales.