The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-03.16)

-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 20, 22

-Article 5

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 944

-SubTopic 210

-Section S99

-Paragraph 1

-Subparagraph (SX 210.7-03.16)

-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

+ Details

Name:	us-gaap_LineOfCredit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_LineOfCreditFacilityAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Date the credit facility terminates, in CCYY-MM-DD format.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(b),22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

+ Details

Name:	us-gaap_LineOfCreditFacilityExpirationDate1
Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

The effective interest rate during the reporting period.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityInterestRateDuringPeriod
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The cash inflow from a contractual arrangement with the lender, including letter of credit, standby letter of credit and revolving credit arrangements, under which borrowings can be made up to a specific amount at any point in time with maturities due beyond one year or the operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Financing Activities

-URI http://asc.fasb.org/extlink&oid=6513228

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 14

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3255-108585

+ Details

Name:	us-gaap_ProceedsFromLongTermLinesOfCredit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The cash outflow for the settlement of obligation drawn from a contractual arrangement with the lender, including letter of credit, standby letter of credit and revolving credit arrangements, under which borrowings can be made up to a specific amount at any point in time with maturities due beyond one year or the operating cycle, if longer.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 15

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3291-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Financing Activities

-URI http://asc.fasb.org/extlink&oid=6513228

+ Details

Name:	us-gaap_RepaymentsOfLongTermLinesOfCredit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Details

Name:	vlo_CreditFacilityAbstract
Namespace Prefix:	vlo_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Debt to capitalization ratios as per terms of revolver.

+ References

No definition available.

+ Details

Name:	vlo_DebtToCapitalizationRatiosAsPerTermsOfRevolver
Namespace Prefix:	vlo_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Aggregate commitments available under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility, subject to certain conditions by obtaining additional commitments from existing and/or new lenders.

+ References

No definition available.

+ Details

Name:	vlo_LineOfCreditFacilityAccordionFeatureHigherBorrowingCapacityOption
Namespace Prefix:	vlo_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

Debt, Credit Facilities (Details)			3 Months Ended		3 Months Ended						3 Months Ended					3 Months Ended
Debt, Credit Facilities (Details)	Mar. 31, 2015 Other Letter of Credit [Member] USD ($)	Dec. 31, 2014 Other Letter of Credit [Member] USD ($)	Mar. 31, 2015 Credit Facilities [Member] Letter of Credit [Member] USD ($)	Dec. 31, 2014 Credit Facilities [Member] Letter of Credit [Member] USD ($)	Mar. 31, 2015 Credit Facilities [Member] U S Revolver [Member] USD ($)	Mar. 31, 2014 Credit Facilities [Member] U S Revolver [Member] USD ($)	Dec. 31, 2014 Credit Facilities [Member] U S Revolver [Member] USD ($)	Mar. 31, 2015 Credit Facilities [Member] U S Revolver [Member] Maximum [Member]	Mar. 31, 2015 Credit Facilities [Member] U S Revolver Letter of Credit [Member] USD ($)	Dec. 31, 2014 Credit Facilities [Member] U S Revolver Letter of Credit [Member] USD ($)	Mar. 31, 2015 Credit Facilities [Member] VLP Revolver [Member] USD ($)	Mar. 31, 2014 Credit Facilities [Member] VLP Revolver [Member] USD ($)	Dec. 31, 2014 Credit Facilities [Member] VLP Revolver [Member] USD ($)	Mar. 31, 2015 Credit Facilities [Member] VLP Revolver Letter of Credit [Member] USD ($)	Dec. 31, 2014 Credit Facilities [Member] VLP Revolver Letter of Credit [Member] USD ($)	Mar. 31, 2015 Credit Facilities [Member] Canadian Revolver [Member] CAD	Mar. 31, 2014 Credit Facilities [Member] Canadian Revolver [Member] CAD	Dec. 31, 2014 Credit Facilities [Member] Canadian Revolver [Member] CAD	Mar. 31, 2015 Credit Facilities [Member] Canadian Revolver Letter of Credit [Member] CAD	Dec. 31, 2014 Credit Facilities [Member] Canadian Revolver Letter of Credit [Member] CAD
Line of Credit Facility
Line of credit facility, maximum borrowing capacity			$ 550,000,000		$ 3,000,000,000						$ 300,000,000					50,000,000
Line of credit facility, expiration date			Jun. 30, 2015		Nov. 30, 2018						Dec. 31, 2018					Nov. 30, 2015
Amount outstanding	204,000,000	80,000,000	0	56,000,000	0		0		64,000,000	54,000,000	200,000,000		0	0	0	0		0	10,000,000	10,000,000
Credit Facilities (Textual)
Line of credit facility, accordion feature, higher borrowing capacity option					4,500,000,000
Debt to capitalization ratios as per terms of revolver								0.60
Borrowings from long-term lines of credit					0	0					200,000,000	0				0	0
Repayments of long-term lines of credit					$ 0	$ 0					$ 0	$ 0				0	0
Line of credit facility, interest rate during period											1.4375%