Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Document Type	dei_DocumentType	Other
Document Period End Date	dei_DocumentPeriodEndDate	Dec. 31, 2010
Registrant Name	dei_EntityRegistrantName	JOHN HANCOCK VARIABLE INSURANCE TRUST
Central Index Key	dei_EntityCentralIndexKey	0000756913
Amendment Flag	dei_AmendmentFlag	false
Document Creation Date	dei_DocumentCreationDate	Jun. 30, 2011
Document Effective Date	dei_DocumentEffectiveDate	Jun. 30, 2011
Prospectus Date	rr_ProspectusDate	May 02, 2011
Supplement [Text Block]	jht756913_SupplementTextBlock	JOHN HANCOCK VARIABLE INSURANCE TRUST Supplement dated June 30, 2011 to the Prospectus dated May 2, 2011
Bond Trust
Risk/Return:	rr_RiskReturnAbstract
Risk/Return [Heading]	rr_RiskReturnHeading	Bond Trust
Supplement [Text Block]	jht756913_SupplementTextBlock	The table under “Examples” in “Annual Fund Operating Expenses” is amended and restated as follows:
Bond Trust \| Series NAV
Risk/Return:	rr_RiskReturnAbstract
Trading Symbol	dei_TradingSymbol	JPNNX
Expense Example:	rr_ExpenseExampleAbstract
Expense Example, By Year, Column [Text]	rr_ExpenseExampleByYearColumnName	Series NAV
Year 1	rr_ExpenseExampleYear01	63
Year 3	rr_ExpenseExampleYear03	199
Year 5	rr_ExpenseExampleYear05	346
Year 10	rr_ExpenseExampleYear10	774

If the value is true, then the document as an amendment to previously-filed/accepted document.

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The date the document was made available and submitted, in CCYY-MM-DD format. The date of submission, date of acceptance by the recipient, and the document effective date are all potentially different.

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- Definition

The date when a document, upon receipt and acceptance, becomes officially effective, in CCYY-MM-DD format. Usually it is a system-assigned date time value, but it may be declared by the submitter in some cases.

+ Details

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- Definition

The end date of the period reflected on the cover page if a periodic report. For all other reports and registration statements this will be the filing date. The format of the date is CCYY-MM-DD.

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- Definition

The type of document being provided (such as 10-K, 10-Q, N-1A, etc). The document type should be limited to the same value as the supporting SEC submission type. The acceptable values are as follows: S-1, S-3, S-4, S-11, F-1, F-3, F-4, F-9, F-10, 6-K, 8-K, 10, 10-K, 10-Q, 20-F, 40-F, N-1A, 485BPOS, NCSR, N-Q, and Other.

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- Definition

A unique 10-digit SEC-issued value to identify entities that have filed disclosures with the SEC. It is commonly abbreviated as CIK.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation 12B
-Number 240
-Section 12b
-Subsection 1

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- Definition

The exact name of the entity filing the report as specified in its charter, which is required by forms filed with the SEC.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation 12B
-Number 240
-Section 12b
-Subsection 1

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- Definition

Trading symbol of an instrument as listed on an exchange.

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- Definition

Supplement Text Block.

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The Example assumes that you invest $10,000 in the Fund for the time periods indicated and then you redeem all of your shares at the end of those periods. The Example also assumes that your investment has a 5% return per year and that the Fund's operating expenses remained the same. Although your actual costs may be higher or lower.

+ References

Reference 1: 1
-Publisher SEC
-Name Form
-Number N-1A
-Chapter A
-Section 3
-Paragraph 1
-Subparagraph 2
-Subsection example

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+ References

Reference 1: 1
-Publisher SEC
-Name Form
-Number N-1A
-Chapter A
-Section 3
-Paragraph 4
-Subsection instructions

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- Definition

+ References

Reference 1: 1
-Publisher SEC
-Name Form
-Number N-1A
-Chapter A
-Section 3
-Paragraph 1
-Subparagraph 2
-Subsection example

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Reference 1: 1
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-Name Form
-Number N-1A
-Chapter A
-Section 3
-Paragraph 1
-Subparagraph 2
-Subsection example

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- Definition

+ References

Reference 1: 1
-Publisher SEC
-Name Form
-Number N-1A
-Chapter A
-Section 3
-Paragraph 1
-Subparagraph 2
-Subsection example

+ Details

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- Definition

The date of the prospectus.

+ References

Reference 1: 1
-Publisher SEC
-Name Form
-Number N-1A
-Chapter A
-Section 1
-Paragraph 3
-Subsection a

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Risk/Return Summary Investment Objectives/Goals Include the following information, in plain English under rule 421(d) under the Securities Act, in the order and subject matter indicated

+ References

Reference 1: 1
-Publisher SEC
-Name Form
-Number N-1A
-Chapter A
-Section 2

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