Basis of Presentation and Summary of Significant Accounting Policies (Policies)	6 Months Ended
	Jun. 30, 2015
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation As used in this report, the terms “Valero,” “we,” “us,” or “our” may refer to Valero Energy Corporation, one or more of its consolidated subsidiaries, or all of them taken as a whole. These unaudited financial statements have been prepared in accordance with United States (U.S.) generally accepted accounting principles (GAAP) for interim financial information and with the instructions to Form 10-Q and Article 10 of Regulation S-X of the Securities Exchange Act of 1934. Accordingly, they do not include all of the information and notes required by U.S. GAAP for complete financial statements. In the opinion of management, all adjustments considered necessary for a fair presentation have been included. All such adjustments are of a normal recurring nature unless disclosed otherwise. Financial information for the three and six months ended June 30, 2015 and 2014 included in these Condensed Notes to Consolidated Financial Statements is derived from our unaudited financial statements. Operating results for the three and six months ended June 30, 2015 are not necessarily indicative of the results that may be expected for the year ending December 31, 2015. The balance sheet as of December 31, 2014 has been derived from our audited financial statements as of that date. For further information, refer to our financial statements and notes thereto included in our annual report on Form 10-K for the year ended December 31, 2014.
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.
New Accounting Pronouncements	New Accounting Pronouncements In May 2014, the Financial Accounting Standards Board (FASB) amended the ASC and issued a new accounting standard, Topic 606, “Revenue from Contracts with Customers,” to clarify the principles for recognizing revenue. The core principle of the new standard is that an entity should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. The standard also requires improved interim and annual disclosures that enable the users of financial statements to better understand the nature, amount, timing, and uncertainty of revenues and cash flows arising from contracts with customers. In July 2015, the FASB deferred the effective date of the new standard by one year. As a result, the standard is effective for annual reporting periods beginning after December 15, 2017, including interim reporting periods within that reporting period, and can be adopted either retrospectively to each prior reporting period presented using a practical expedient, as allowed by the standard, or retrospectively with a cumulative effect adjustment to retained earnings as of the date of initial application. Early adoption is permitted, but not before the original effective date, which was for annual reporting periods beginning after December 15, 2016, including interim reporting periods within those reporting periods. We are currently evaluating the effect that adopting this standard will have on our financial statements and related disclosures. In February 2015, the provisions of ASC Topic 810, “Consolidation” were amended to improve consolidation guidance for certain types of legal entities. The guidance modifies the evaluation of whether limited partnerships and similar legal entities are variable interest entities (VIEs) or voting interest entities, eliminates the presumption that a general partner should consolidate a limited partnership, affects the consolidation analysis of reporting entities that are involved with VIEs, particularly those that have fee arrangements and related party relationships, and provides a scope exception from consolidation guidance for certain money market funds. These provisions are effective for annual reporting periods beginning after December 15, 2015, and interim periods within those annual periods, with early adoption permitted. These provisions may also be adopted retrospectively in previously issued financial statements for one or more years with a cumulative-effect adjustment to retained earnings as of the beginning of the first year restated. The adoption of this guidance effective January 1, 2016 will not affect our financial position or results of operations, but will result in additional disclosures. In April 2015, the provisions of ASC Subtopic 835-30, “Interest–Imputation of Interest” were amended to simplify the presentation of debt issuance costs. The guidance requires that debt issuance costs related to a note be reported in the balance sheet as a direct deduction from the face amount of that note, consistent with debt discounts, and that amortization of debt issuance costs be reported as interest expense. These provisions are to be applied retrospectively and are effective for annual reporting periods beginning after December 15, 2015, and interim periods within those annual periods, with early adoption permitted. The adoption of this guidance effective January 1, 2016 will not materially affect our financial position or results of operations; however, our debt issuance costs associated with issued debt will be reported in the balance sheet as a direct deduction from “debt and capital lease obligations, less current portion” and excluded from “deferred charges and other assets, net.” Also in April 2015, the provisions of ASC Topic 715, “Compensation–Retirement Benefits” were amended to provide a practical expedient for the measurement date of an entities’ defined benefit pension or other postretirement plans. For an entity with a fiscal year-end that does not coincide with a month-end, the guidance provides a practical expedient that allows the entity to measure the defined benefit plan assets and obligations using the month-end that is closest to the entity’s fiscal year-end. For an entity that has a significant event in an interim period that calls for a remeasurement, the guidance allows an entity to remeasure the defined benefit plan assets and obligations using the month-end that is closest to the date of the significant event. These provisions are effective retrospectively for annual reporting periods beginning after December 15, 2015, and interim periods within those annual periods, with early adoption permitted. The adoption of this guidance effective January 1, 2016 will not affect our financial position or results of operations. In May 2015, the FASB amended the provisions of ASC Topic 820, “Fair Value Measurements,” to remove the requirement to categorize within the fair value hierarchy all investments for which fair value is measured using the net asset value per share practical expedient. The guidance also removes the requirement to make certain disclosures for all investments that are eligible to be measured using the net asset value per share practical expedient and limits those disclosures to investments for which the entity has elected to measure the fair value using that practical expedient. These provisions are to be applied retrospectively and are effective for annual reporting periods beginning after December 15, 2015, and interim periods within those annual periods, with early adoption permitted. The adoption of this guidance effective January 1, 2016 will not affect our financial position or results of operations, but will result in revised disclosures. In July 2015, the provisions of ASC Topic 330, “Inventory” were amended to simplify the measurement of inventory. The guidance does not apply to inventory where the cost of such inventory is measured using the last-in, first-out (LIFO) or the retail inventory methods. The guidance applies to inventory where the cost of such inventory is measured using the first-in, first-out (FIFO) or average cost methods, and it requires the inventory to be measured at the lower of cost and net realizable value rather than the lower of cost or market. Net realizable value is defined as the estimated selling prices in the ordinary course of business, less reasonably predicable costs of completion, disposal, and transportation. These provisions are to be applied prospectively and are effective for annual reporting periods beginning after December 15, 2016, and interim periods within those annual periods, with early adoption permitted. The adoption of this guidance effective January 1, 2017 is not expected to affect our financial position or results of operations.
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 on a gross basis in the tables below. We have no derivative contracts that are subject to master netting arrangements that are reflected gross on the balance sheet.
Derivatives	We are exposed to market risks related to the volatility in the price of commodities, interest rates, and foreign currency exchange rates. We enter into derivative instruments to manage some of these risks, including derivative instruments related to the various commodities we purchase or produce, interest rate swaps, 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 11), as summarized below under “Fair Values of Derivative Instruments.” In addition, the effect of these derivative instruments on our income is summarized below under “Effect of Derivative Instruments on Income and Other Comprehensive Income.” When we enter into a derivative instrument, it is designated as a fair value hedge, a cash flow hedge, an economic hedge, or a trading derivative. The gain or loss on a derivative instrument designated and qualifying as a fair value hedge, as well as the offsetting loss or gain on the hedged item attributable to the hedged risk, is recognized currently in income in the same period. The effective portion of the gain or loss on a derivative instrument designated and qualifying as a cash flow hedge is initially reported as a component of other comprehensive income and is then recorded into income in the period or periods during which the hedged forecasted transaction affects income. The ineffective portion of the gain or loss on the cash flow derivative instrument, if any, is recognized in income as incurred. For our economic hedges (derivative instruments not designated as fair value or cash flow hedges) and for derivative instruments entered into by us for trading purposes, the derivative instrument is recorded at fair value and changes in the fair value of the derivative instrument are recognized currently in income. The cash flow effects of all of our derivative instruments are reflected in operating activities in our statements of cash flows for all periods presented.
Derivative instruments collateral requirements	We do not require any collateral or other security to support derivative instruments into which we enter.