v3.26.1
MFS Research International Portfolio Investment Objectives and Goals - MFS Research International Portfolio
Dec. 31, 2025
Prospectus [Line Items]  
Risk/Return [Heading] <span style="color:#000000;font-family:Times New Roman;font-size:22pt;">MFS</span><span style="color:#000000;font-family:Times New Roman;font-size:14pt;position:relative;top:-9.5pt;">®</span><span style="color:#000000;font-family:Times New Roman;font-size:22pt;"> Research International Portfolio</span>
Objective [Heading] <span style="color:#000000;font-family:Times New Roman;font-size:11.5pt;font-weight:bold;">Investment Objective</span>
Objective, Primary [Text Block] Capital appreciation.