Label

Element

Value

Risk/Return:

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Document Type

dei_DocumentType

Other

Document Period End Date

dei_DocumentPeriodEndDate

Dec. 31, 2012

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

May 17, 2013

Document Effective Date

dei_DocumentEffectiveDate

May 17, 2013

Prospectus Date

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Apr. 26, 2013

Supplement -- [Text Block]

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John Hancock Variable Insurance Trust
Supplement dated May 17, 2013
to the Prospectus April 26, 2013

The fifth paragraph under the heading "Principal Investment Strategies" is revised and restated as follows:

Depending on the subadviser's current opinion as to the proper allocation of assets among domestic and foreign issuers, investments that are economically tied to foreign (non-U.S.) countries will normally be at least 25% of the fund's net assets. The fund may invest, without limitation, in securities and instruments that are economically tied to emerging countries. The fund may invest up to 10% of its total assets in fixed-income securities that are rated below investment grade but rated B or higher by Moody's or equivalently rated by S&P or Fitch, or, if unrated, determined by the subadviser to be of comparable quality (except that within such limitations, the fund may invest in mortgage-related securities and variable rate master demand notes rated below B). The fund may invest in baskets of foreign currencies (such as the euro) and directly in currencies. The average portfolio duration of the fund normally varies within three years (plus or minus) of the duration of the benchmark index, as calculated by the subadviser.

John Hancock Variable Insurance Trust | Global Bond Fund

Risk/Return:

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Strategy - Supplement [Text Block]

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The fifth paragraph under the heading "Principal Investment Strategies" is revised and restated as follows:

Strategy Narrative [Text Block]

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Depending on the subadviser's current opinion as to the proper allocation of assets among domestic and foreign issuers, investments that are economically tied to foreign (non-U.S.) countries will normally be at least 25% of the fund's net assets. The fund may invest, without limitation, in securities and instruments that are economically tied to emerging countries. The fund may invest up to 10% of its total assets in fixed-income securities that are rated below investment grade but rated B or higher by Moody's or equivalently rated by S&P or Fitch, or, if unrated, determined by the subadviser to be of comparable quality (except that within such limitations, the fund may invest in mortgage-related securities and variable rate master demand notes rated below B). The fund may invest in baskets of foreign currencies (such as the euro) and directly in currencies. The average portfolio duration of the fund normally varies within three years (plus or minus) of the duration of the benchmark index, as calculated by the subadviser.