The amount of a reclassification adjustment made to prior period financial statement amounts.

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

- Definition

The amount of financial or other support the reporting entity has provided (explicitly or implicitly) to the Variable Interest Entity (VIE) that it was not previously contractually required to provide or that the reporting entity intends to provide, including, for example, situations in which the reporting entity assisted the VIE in obtaining another type of support.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 810

-SubTopic 10

-Section 50

-Paragraph 5A

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=6970148&loc=SL6759159-111685

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

-Publisher FASB

-Name FASB Staff Position (FSP)

-Number FAS140-4/FIN46(R)-8

-Paragraph C4

-Subparagraph c

-Clause 1

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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.

+ Details

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

- Definition

Percentage of the Variable Interest Entity's (VIE) voting interest owned by (or beneficial interest in) the reporting entity (directly or indirectly).

+ References

+ Details

Name:	us-gaap_VariableInterestEntityOwnershipPercentage
Namespace Prefix:	us-gaap
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Discloses the date when the relationship between the reporting entity and the Variable Interest Entity (VIE) began.

+ References

+ Details

Name:	us-gaap_VariableInterestEntityQualitativeOrQuantitativeInformationDateInvolvementBegan
Namespace Prefix:	us-gaap
Data Type:	us-types:dateStringItemType
Balance Type:	na
Period Type:	duration

- Definition

Consolidation of Joint Venture (Textual) [Abstract]

+ Details

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

- Definition

The estimated aggregate cost of expenditures to construct a greenfield diesel plant.

+ Details

Name:	vlo_EstimatedAggregateCostToConstructDieselPlant
Namespace Prefix:	vlo
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Feed Capacity of Diesel Plants

+ Details

Name:	vlo_FeedCapacityOfDieselPlants
Namespace Prefix:	vlo
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Reclassifications (Textual) [Abstract]

+ Details

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Namespace Prefix:	vlo
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Balance Type:	na
Period Type:	duration

- Definition

Variable Interest Entity, Financial or Other Support, Date of Agreement - date when financial support was issued, which is presented in month, day, and year order.

+ Details

Name:	vlo_VariableInterestEntityFinancialOrOtherSupportDateOfAgreement
Namespace Prefix:	vlo
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum percentage of construction costs financed under joint venture agreement.

+ Details

Name:	vlo_VariableInterestEntityMaximumPercentageOfConstructionCostsFinanced
Namespace Prefix:	vlo
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

Basis of Presentation and Summary of Significant Accounting Policies (Details) (USD $) In Millions, unless otherwise specified	1 Months Ended	0 Months Ended	3 Months Ended	9 Months Ended	0 Months Ended	9 Months Ended
	May 31, 2011	Jan. 21, 2011	Sep. 30, 2010	Sep. 30, 2010	Aug. 01, 2011 Variable Interest Entity, Primary Beneficiary [Member]	Sep. 30, 2011 Variable Interest Entity, Primary Beneficiary [Member]	Sep. 30, 2011 Variable Interest Entity, Not Primary Beneficiary [Member]
Reclassifications (Textual)
Reclassification to cost of sales from operating expenses			$ 23	$ 68
Noncontrolling Interests (Textual)
JV ownership percentage					85.00%	50.00%	50.00%
Date JV involvement began		1/21/2011
Feed capacity of diesel plants		10,000
Estimated aggregate cost to construct diesel plant		368
JV financial support agreement date	May 31, 2011
JV financial support amount	$ 221
JV maximum percentage of construction costs financed	0.6