v3.26.1
SA AB Small and Mid Cap Value Portfolio Performance Management - SA AB Small and Mid Cap Value Portfolio
Dec. 31, 2025
Prospectus [Line Items]  
Bar Chart and Performance Table [Heading] <span style="color:#000000;font-family:Arial;font-size:12pt;font-style:italic;font-weight:bold;">Performance Information</span>
Performance Narrative [Text Block] The following bar chart illustrates the risks of investing in the Portfolio by showing changes in the Portfolio’s performance from calendar year to calendar year and the table compares the Portfolio’s average annual returns to those of the Russell 3000® Index (a broad-based securities market index) and the Russell 2500® Value Index, which is relevant to the Portfolio because it has characteristics similar to the Portfolio’s investment strategies. Fees and expenses incurred at the contract level are not reflected in the bar chart or table. If these amounts were reflected, returns would be less than those shown. Of course, past performance is not necessarily an indication of how the Portfolio will perform in the future.
Performance Past Does Not Indicate Future [Text] <span style="color:#000000;font-family:Arial;font-size:10pt;"> Of course, past performance is not necessarily an indication of how the Portfolio will perform in the future.</span>
Performance Information Illustrates Variability of Returns [Text] <span style="color:#000000;font-family:Arial;font-size:10pt;margin-left:0%;">The following bar chart illustrates the risks of investing in the Portfolio by showing changes in the Portfolio’s performance from calendar year to calendar year and the table compares the Portfolio’s average annual returns to those of the Russell 3000</span><span style="color:#000000;font-family:Arial;font-size:6.5pt;position:relative;top:-3.25pt;">®</span><span style="color:#000000;font-family:Arial;font-size:10pt;"> Index (a broad-based </span><span style="color:#000000;font-family:Arial;font-size:10pt;margin-left:0%;">securities market index) and the Russell 2500</span><span style="color:#000000;font-family:Arial;font-size:6.5pt;position:relative;top:-3.25pt;">®</span><span style="color:#000000;font-family:Arial;font-size:10pt;"> Value </span><span style="color:#000000;font-family:Arial;font-size:10pt;margin-left:0%;">Index, which is relevant to the Portfolio because it has characteristics similar to the Portfolio’s investment strategies.</span>
Bar Chart Does Not Reflect Sales Loads [Text] <span style="color:#000000;font-family:Arial;font-size:10pt;"> Fees and expenses incurred at the contract </span><span style="color:#000000;font-family:Arial;font-size:10pt;margin-left:0%;">level are not reflected in the bar chart or table. If these amounts were reflected, returns would be less than those shown.</span>
Bar Chart [Heading] <span style="font-family:Arial;font-size:10pt;font-weight:bold;">(Class 2 Shares)</span>
Bar Chart Closing [Text Block] During the period shown in the bar chart:Highest Quarterly Return:December 31, 202028.97%Lowest Quarterly Return:March 31, 2020-36.36%Year to Date Most Recent Quarter:March 31, 20263.21%
Performance Table Heading <span style="font-family:Arial;font-size:10pt;font-weight:bold;margin-left:0%;">Average Annual Total Returns</span><span style="font-family:Arial;font-size:10pt;"> (For the periods ended December 31, 2025)</span>
Class 2  
Prospectus [Line Items]  
Year to Date Return, Label [Optional Text] <span style="font-family:Arial;font-size:10pt;margin-left:0.0pt;">Year to Date Most </span><span style="font-family:Arial;font-size:10pt;margin-left:0.0pt;">Recent Quarter:</span>
Bar Chart, Year to Date Return 3.21%
Bar Chart, Year to Date Return, Date Mar. 31, 2026
Highest Quarterly Return, Label [Optional Text] <span style="font-family:Arial;font-size:10pt;margin-left:0.0pt;">Highest Quarterly </span><span style="font-family:Arial;font-size:10pt;margin-left:0.0pt;">Return:</span>
Highest Quarterly Return 28.97%
Highest Quarterly Return, Date Dec. 31, 2020
Lowest Quarterly Return, Label [Optional Text] <span style="font-family:Arial;font-size:10pt;margin-left:0.0pt;">Lowest Quarterly </span><span style="font-family:Arial;font-size:10pt;margin-left:0.0pt;">Return:</span>
Lowest Quarterly Return (36.36%)
Lowest Quarterly Return, Date Mar. 31, 2020