2.4.0.8030000 - Document - Risk/Return Detail {Unlabeled}falsefalsetrue1false falsefalsechttp://www.sec.gov/CIK0000756913duration2013-06-28T00:00:002013-06-28T00:00:001false 2rr_RiskReturnDetailTableTextBlockrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00<div style="display: none">~ http://xbrl.sec.gov/rr/role/RiskReturnDetailData column period compact * row dei_DocumentInformationDocumentAxis compact * row dei_LegalEntityAxis compact * row rr_ProspectusShareClassAxis compact * row rr_PerformanceMeasureAxis compact * row primary compact * ~</div>falsefalse<div style="display: none">~ http://xbrl.sec.gov/rr/role/RiskReturnDetailData column period compact * row dei_DocumentInformationDocumentAxis compact * row dei_LegalEntityAxis compact * row rr_ProspectusShareClassAxis compact * row rr_PerformanceMeasureAxis compact * row primary compact * ~</div>falsehttp://xbrl.sec.gov/rr/role/RiskReturnDetailData2.4.0.8040000 - Disclosure - Risk/Return Detail Data {Elements}truetruefalse1false falsefalsechttp://www.sec.gov/CIK0000756913duration2013-06-28T00:00:002013-06-28T00:00:001true 1rr_RiskReturnAbstractrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Risk/Return:2false 2dei_DocumentTypedei_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00Otherfalsefalsefalseus-types:SECReportItemTypenaThe 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.No definition available.false0Document Type3false 2dei_DocumentPeriodEndDatedei_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse002012-12-31falsefalsetruexbrli:dateItemTypedateThe 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.No definition available.false0Document Period End Date4false 2dei_EntityRegistrantNamedei_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00JOHN HANCOCK VARIABLE INSURANCE TRUSTfalsefalsefalsexbrli:normalizedStringItemTypenormalizedstringThe exact name of the entity filing the report as specified in its charter, which is required by forms filed with the SEC.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation 12B -Number 240 -Section 12b -Subsection 1 false0Registrant Name5false 2dei_EntityCentralIndexKeydei_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse000000756913falsefalsefalseus-types:centralIndexKeyItemTypenaA unique 10-digit SEC-issued value to identify entities that have filed disclosures with the SEC. It is commonly abbreviated as CIK.Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation 12B -Number 240 -Section 12b -Subsection 1 false0Central Index Key6false 2dei_AmendmentFlagdei_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsefalsexbrli:booleanItemTypenaIf the value is true, then the document as an amendment to previously-filed/accepted document.No definition available.false0Amendment Flag7false 2dei_DocumentCreationDatedei_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse002013-06-28falsefalsetruexbrli:dateItemTypedateThe 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.No definition available.false0Document Creation Date8false 2dei_DocumentEffectiveDatedei_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse002013-06-28falsefalsetruexbrli:dateItemTypedateThe 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.No definition available.false0Document Effective Date9false 2rr_ProspectusDaterr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse002013-04-29falsefalsetruexbrli:dateItemTypedateThe date of the prospectus.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 1 -Paragraph 3 -Subsection a false0Prospectus Date10false 2jhvitlifemod_SupplementTextBlock_04jhvitlifemod_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00 <div align="center"> John Hancock Variable Insurance Trust Supplement dated June 28, 2013 To the Prospectus dated April 29, 2013 </div>   LIFESTYLE MODERATE PS SERIES The principal investment strategies for the Lifestyle Moderate PS Series are amended and restated as follows: Principal Investment Strategies The fund, except as otherwise described below, operates as a fund of funds and normally invests approximately 40% of its assets in underlying funds that invest primarily in equity securities or in futures contracts on equity markets (the "Equity Allocation") and approximately 60% of its assets in underlying funds that invest primarily in fixed-income securities or in futures contracts on fixed income markets (the "Fixed Income Allocation"). Underlying funds may include exchange traded funds ("ETFs") and the fund may invest a significant portion of its assets in ETFs. At the discretion of the subadvisor, the Equity Allocation may also include direct investments in equity securities and the Fixed Income Allocation may also include direct investments in fixed-income securities. The subadvisor may also determine in light of market or economic conditions that the normal percentage limitations should be exceeded to protect the fund or achieve its objective. Within the prescribed percentage allocation, the subadvisor selects the percentage level to be maintained in specific underlying funds and in futures contracts on equity or fixed income markets. These allocations may be changed at any time by the subadvisor. The fund may invest in various underlying funds that as a group hold a wide range of equity type securities. These include small-, mid- and large-capitalization stocks, domestic and foreign securities (including emerging market securities) and sector holdings such as utilities and science and technology stocks. Each of these underlying funds has its own investment strategy which, for example, may focus on growth stocks or value stocks or may employ a strategy combining growth and income stocks and/or may invest in derivatives such as options on securities and futures contracts. The fund may also invest in underlying funds that purchase futures contracts on equity markets. Certain of these underlying funds focus their investment strategy on fixed-income securities, which may include investment grade and below investment grade debt securities with maturities that range from short to longer term. The fixed-income underlying funds collectively hold various types of debt instruments such as corporate bonds and mortgage backed, U.S. and foreign government issued, domestic and international securities. The fund may invest in derivatives, which are financial contracts with a value that depends on, or is derived from, the value of underlying assets, reference rates or indexes. Derivatives may relate to stocks, bonds, interest rates, currencies or currency exchange rates and related indexes. The fund may use derivatives for hedging and nonhedging purposes including, without limitation, the following purposes: To establish a position in the derivatives markets as a method of gaining exposure to a particular security or market; To attempt to protect against possible changes in the market value of securities held or to be purchased by the fund or an underlying fund; To manage the effective maturity or duration of the securities of the fund or an underlying fund; and To facilitate the repatriation of foreign currency and the settlement of purchases of foreign securities. The fund may invest in other types of investments as described under "Other Permitted Investments of the Fund of Funds." The fund bears its own expenses and, in addition, indirectly bears its proportionate share of the expenses of the underlying funds in which it invests. falsefalsefalseus-types:textBlockItemTypestringNo authoritative reference available.No definition available.false0Supplement -- [Text Block]11false 0truefalsetruefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalse2false truefalsec_S000032007_AAAAhttp://www.sec.gov/CIK0000756913duration2013-06-28T00:00:002013-06-28T00:00:00falsefalsejhvitlifemod_AAAAMemberdei_DocumentInformationDocumentAxisxbrldihttp://xbrl.org/2006/xbrldijhvitlifemod_AAAAMemberdei_DocumentInformationDocumentAxisexplicitMemberfalsefalsejhvitlifemod_S000032007Memberdei_LegalEntityAxisxbrldihttp://xbrl.org/2006/xbrldijhvitlifemod_S000032007Memberdei_LegalEntityAxisexplicitMembernanafalse0John Hancock Variable Insurance Trust | (Lifestyle Moderate PS Series)12true 1rr_RiskReturnAbstractrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00falsefalsefalsexbrli:stringItemTypestringfalse0Risk/Return:13false 2jhvitlifemod_SupplementTextBlockjhvitlifemod_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalselabel1falsefalsefalse00 The principal investment strategies for the Lifestyle Moderate PS Series are amended and restated as follows: falsefalsefalseus-types:textBlockItemTypestringNo authoritative reference available.No definition available.false0Strategy - Supplement [Text Block]14false 2rr_StrategyHeadingrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00 Principal Investment Strategies falsefalsefalsexbrli:stringItemTypestringPrincipal investment strategies of the Fund. Summarize how the Fund intends to achieve its investment objectives by identifying the Fund's principal investment strategies (including the type or types of securities in which the Fund invests or will invest principally) and any policy to concentrate in securities of issuers in a particular industry or group of industries.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection a false0Strategy [Heading]15false 2rr_StrategyNarrativeTextBlockrr_falsenadurationfalsefalsefalsefalsefalsefalsefalsefalse1falsefalsefalse00 The fund, except as otherwise described below, operates as a fund of funds and normally invests approximately 40% of its assets in underlying funds that invest primarily in equity securities or in futures contracts on equity markets (the "Equity Allocation") and approximately 60% of its assets in underlying funds that invest primarily in fixed-income securities or in futures contracts on fixed income markets (the "Fixed Income Allocation"). Underlying funds may include exchange traded funds ("ETFs") and the fund may invest a significant portion of its assets in ETFs. At the discretion of the subadvisor, the Equity Allocation may also include direct investments in equity securities and the Fixed Income Allocation may also include direct investments in fixed-income securities. The subadvisor may also determine in light of market or economic conditions that the normal percentage limitations should be exceeded to protect the fund or achieve its objective. Within the prescribed percentage allocation, the subadvisor selects the percentage level to be maintained in specific underlying funds and in futures contracts on equity or fixed income markets. These allocations may be changed at any time by the subadvisor. The fund may invest in various underlying funds that as a group hold a wide range of equity type securities. These include small-, mid- and large-capitalization stocks, domestic and foreign securities (including emerging market securities) and sector holdings such as utilities and science and technology stocks. Each of these underlying funds has its own investment strategy which, for example, may focus on growth stocks or value stocks or may employ a strategy combining growth and income stocks and/or may invest in derivatives such as options on securities and futures contracts. The fund may also invest in underlying funds that purchase futures contracts on equity markets. Certain of these underlying funds focus their investment strategy on fixed-income securities, which may include investment grade and below investment grade debt securities with maturities that range from short to longer term. The fixed-income underlying funds collectively hold various types of debt instruments such as corporate bonds and mortgage backed, U.S. and foreign government issued, domestic and international securities. The fund may invest in derivatives, which are financial contracts with a value that depends on, or is derived from, the value of underlying assets, reference rates or indexes. Derivatives may relate to stocks, bonds, interest rates, currencies or currency exchange rates and related indexes. The fund may use derivatives for hedging and nonhedging purposes including, without limitation, the following purposes: To establish a position in the derivatives markets as a method of gaining exposure to a particular security or market; To attempt to protect against possible changes in the market value of securities held or to be purchased by the fund or an underlying fund; To manage the effective maturity or duration of the securities of the fund or an underlying fund; and To facilitate the repatriation of foreign currency and the settlement of purchases of foreign securities. The fund may invest in other types of investments as described under "Other Permitted Investments of the Fund of Funds." The fund bears its own expenses and, in addition, indirectly bears its proportionate share of the expenses of the underlying funds in which it invests. falsefalsefalseus-types:textBlockItemTypestringPrincipal investment strategies of the Fund. Summarize how the Fund intends to achieve its investment objectives by identifying the Fund's principal investment strategies (including the type or types of securities in which the Fund invests or will invest principally) and any policy to concentrate in securities of issuers in a particular industry or group of industries.Reference 1: 1 -Publisher SEC -Name Form -Number N-1A -Chapter A -Section 4 -Subsection a false0Strategy Narrative [Text Block]falseRisk/Return Detail DataUnKnownUnKnownUnKnownUnKnowntruetruefalseSheethttp://xbrl.sec.gov/rr/role/RiskReturnDetailData115000000ColumnperiodPeriod*Rowdei_DocumentInformationDocumentAxisAxis*Rowdei_LegalEntityAxisAxis*Rowrr_ProspectusShareClassAxisAxis*Rowrr_PerformanceMeasureAxisAxis*RowprimaryElement*falseus-types:textBlockItemTypestringContains a command for the SEC Viewer for the role corresponding to RiskReturnDetailDataNo definition available.false0Risk/Return Detail [Table]falseRisk/Return DetailUnKnownUnKnownUnKnownUnKnowntruefalsefalseSheethttp://xbrl.sec.gov/rr/role/RiskReturnDetail11