3.24.2.u1 html 3019 26 1 false 446 0 false 6 false false R1.htm 030000 - Disclosure - Form N-CSR Cover Sheet http://xbrl.sec.gov/oef/role/NcsrCover Form N-CSR Cover Cover 1 false false R2.htm 030001 - Disclosure - Shareholder Report Sheet http://xbrl.sec.gov/oef/role/ShareholderReport Shareholder Report Notes 2 false false R3.htm 040020 - Disclosure - Shareholder Report, Holdings (Details) Sheet http://xbrl.sec.gov/oef/role/ShareholderReportHoldingsDetails Shareholder Report, Holdings (Details) Details 3 false false R9999.htm Uncategorized Items - f39308d1.htm Sheet http://xbrl.sec.gov/role/uncategorizedFacts Uncategorized Items - f39308d1.htm Cover 4 false false All Reports Book All Reports f39308d1.htm jhvit-20240814.xsd chartimages_5321995.jpg chartimages_5322031.jpg chartimages_5322067.jpg chartimages_5322307.jpg chartimages_5322343.jpg chartimages_5322379.jpg chartimages_5322599.jpg chartimages_5322614.jpg chartimages_5322641.jpg chartimages_5322683.jpg chartimages_5322698.jpg chartimages_5322725.jpg chartimages_5322767.jpg chartimages_5322782.jpg chartimages_5322809.jpg chartimages_5322851.jpg chartimages_5322866.jpg chartimages_5322893.jpg chartimages_5322935.jpg chartimages_5322965.jpg chartimages_5323306.jpg chartimages_5323308.jpg chartimages_5323322.jpg chartimages_5323388.jpg chartimages_5323424.jpg chartimages_5323460.jpg chartimages_5323532.jpg chartimages_5323568.jpg chartimages_5323604.jpg chartimages_5324630.jpg chartimages_5324666.jpg chartimages_5324702.jpg chartimages_5324911.jpg chartimages_5324947.jpg chartimages_5324983.jpg chartimages_5325662.jpg chartimages_5325698.jpg chartimages_5325734.jpg chartimages_5325890.jpg chartimages_5325926.jpg chartimages_5325962.jpg chartimages_5326034.jpg chartimages_5326070.jpg chartimages_5326106.jpg chartimages_5326605.jpg chartimages_5326641.jpg chartimages_5326660.jpg chartimages_5326876.jpg images_4525.jpg images_4547.jpg img28b4a7f01.gif img31c7f2ce1.gif img37a31bab2.gif img726a4c521.jpg img8c6145902.gif imgba627d342.gif imgbda8bc921.gif http://fasb.org/us-gaap/2023 http://xbrl.sec.gov/dei/2023 http://xbrl.sec.gov/oef/2023 false false