v3.26.1
Form N-1A Cover
Dec. 31, 2025
Prospectus [Line Items]  
Document Type 497
Amendment Flag false
Registrant Name VANGUARD VARIABLE INSURANCE FUNDS
Entity Central Index Key 0000857490
Entity Investment Company Type N-1A
Document Period End Date Dec. 31, 2025
Prospectus Date Apr. 28, 2026