Document and Entity Information	12 Months Ended
	Apr. 30, 2012
Risk/Return:
Document Type	Other
Document Period End Date	Dec. 31, 2011
Registrant Name	JOHN HANCOCK VARIABLE INSURANCE TRUST
Central Index Key	0000756913
Amendment Flag	false
Document Creation Date	Jun. 01, 2012
Document Effective Date	Jun. 01, 2012
Prospectus Date	Apr. 30, 2012