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Amount borrowed under the credit facility as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 19, 22
-Article 5

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Reflects when the credit facility terminates, which may be presented in a variety of ways (year, month and year, day, month and year, quarter).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 129
-Paragraph 2, 4
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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

Reference 3: 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

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- 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

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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
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3255-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 95
-Paragraph 18
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 95
-Paragraph 19
-Subparagraph b
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: 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

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Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The cash inflow from other borrowing not otherwise defined in the taxonomy.

+ References

+ Details

Name:	us-gaap_ProceedsFromOtherDebt
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=6943989&loc=d3e3291-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 95
-Paragraph 18
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Statement of Financial Accounting Standard (FAS)
-Number 95
-Paragraph 20
-Subparagraph b
-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Financing Activities
-URI http://asc.fasb.org/extlink&oid=6513228

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Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The cash outflow for the payment of other borrowing not otherwise defined in the taxonomy.

+ References

+ Details

Name:	us-gaap_RepaymentsOfOtherDebt
Namespace Prefix:	us-gaap
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Accounts Receivable Sales Facility Maximum Borrowing Capacity.

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Namespace Prefix:	vlo
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Accounts receivable sales program.

+ Details

Name:	vlo_AccountsReceivableSalesProgramAbstract
Namespace Prefix:	vlo
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Credit Facility.

+ 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.

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Namespace Prefix:	vlo
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	instant

- Definition

Receivables sold to the third-party entities and financial institutions.

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Namespace Prefix:	vlo
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Extended term of accounts receivable sales facility.

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Namespace Prefix:	vlo
Data Type:	us-types:dateStringItemType
Balance Type:	na
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Debt, Credit Facilities (Details)	3 Months Ended	6 Months Ended				3 Months Ended	6 Months Ended					3 Months Ended		6 Months Ended					3 Months Ended		3 Months Ended
Debt, Credit Facilities (Details)	Jun. 30, 2011 USD ($)	Jun. 30, 2011 USD ($)	Jun. 30, 2010 USD ($)	Dec. 31, 2010 USD ($)	Jun. 30, 2011 Maximum [Member] U S Revolver [Member]	Jun. 30, 2011 U S Revolver [Member] USD ($)	Jun. 30, 2011 U S Revolver [Member] USD ($)	Jun. 30, 2010 U S Revolver [Member] USD ($)	Dec. 31, 2010 U S Revolver [Member] USD ($)	Jun. 30, 2011 U S Revolver Letter of Credit [Member] USD ($)	Dec. 31, 2010 U S Revolver Letter of Credit [Member] USD ($)	Jun. 30, 2011 Canadian Revolver [Member] USD ($)	Jun. 30, 2011 Canadian Revolver [Member] CAD	Jun. 30, 2011 Canadian Revolver [Member] USD ($)	Jun. 30, 2010 Canadian Revolver [Member] USD ($)	Dec. 31, 2010 Canadian Revolver [Member] USD ($)	Jun. 30, 2011 Canadian Revolver Letter of Credit [Member] CAD	Dec. 31, 2010 Canadian Revolver Letter of Credit [Member] CAD	Jun. 30, 2011 Short Term Revolving Letter of Credit [Member] USD ($)	Dec. 31, 2010 Short Term Revolving Letter of Credit [Member] USD ($)	Jun. 30, 2011 One Year Revolving Letter Of Credit [Member] USD ($)	Dec. 31, 2010 One Year Revolving Letter Of Credit [Member] USD ($)	Jun. 30, 2011 Other Letter of Credit [Member] USD ($)	Dec. 31, 2010 Other Letter of Credit [Member] USD ($)
Line of Credit Facility
Line of credit facility, maximum borrowing capacity						$ 2,400,000,000	$ 2,400,000,000						115,000,000						$ 200,000,000		$ 300,000,000
Line of credit facility, expiration date						November 2012						December 2012	December 2012						June 2012		June 2012
Letters of credit outstanding						0	0		0	123,000,000	399,000,000	0		0		0	20,000,000	20,000,000	200,000,000	0	230,000,000	100,000,000	223,000,000	176,000,000
Credit Facilities (Textual)
Debt to capitalization ratios as per terms of revolver					0.6	0.18	0.18		0.25
Borrowings from long-term lines of credit							0	0						0	0
Repayments of long-term lines of credit							0	0						0	0
Accounts Receivable Sales Facility (Textual)
Maximum eligible trade receivables	1,000,000,000	1,000,000,000
Extended term of accounts receivable sales facility	June 2012
Eligible receivables sold to third party entities and financial institutions	100,000,000	100,000,000		100,000,000
Sale of eligible receivable to third party entities and financial institutions		0	1,225,000,000
Repayment of eligible receivables		$ 0	$ 1,325,000,000