v3.26.3
International Equities Index Fund Performance Management - International Equities Index Fund
May 31, 2026
Prospectus [Line Items]  
Bar Chart and Performance Table [Heading] <span style="color:#000000;font-family:Arial;font-size:12pt;font-weight:bold;">Performance Information</span>
Performance Narrative [Text Block] The below bar chart and table illustrate the risks of investing in the Fund by showing changes in the Fund’s performance from calendar year to calendar year and comparing the Fund’s average annual returns to those of the MSCI EAFE Index (net) (a broad-based securities market index), which is relevant to the Fund because it has characteristics similar to the Fund’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 of the Fund is not necessarily an indication of how the Fund will perform in the future.BlackRock Investment Management, LLC (“BlackRock”) assumed sub‑advisory responsibilities on April 30, 2025. Prior to this time, the Fund was sub‑advised by SunAmerica Asset Management, LLC.
Performance Past Does Not Indicate Future [Text] <span style="font-family:Arial;font-size:10pt;">Of </span><span style="font-family:Arial;font-size:10pt;margin-left:0%;">course, past performance of the Fund is not necessarily </span><span style="font-family:Arial;font-size:10pt;">an indication of how the Fund will perform in the future.</span>
Performance Information Illustrates Variability of Returns [Text] <span style="font-family:Arial;font-size:10pt;margin-left:0%;">The below bar chart and table illustrate the risks of investing in the Fund by showing changes in the Fund’s performance from calendar year to calendar year and comparing the Fund’s average annual returns to those of the MSCI EAFE Index (net) (a broad-based securities market index), which is relevant to the Fund because it has characteristics similar to the Fund’s investment strategies.</span>
Bar Chart Does Not Reflect Sales Loads [Text] <span style="font-family:Arial;font-size:10pt;margin-left:0%;">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. </span>
Bar Chart Closing [Text Block] During the period shown in the bar chart:Highest Quarterly Return:December 31, 202218.18%Lowest Quarterly Return:March 31, 2020-22.83%Year to Date Most Recent Quarter:June 30, 20269.97%
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>
None  
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 9.97%
Bar Chart, Year to Date Return, Date Jun. 30, 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 18.18%
Highest Quarterly Return, Date Dec. 31, 2022
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 (22.83%)
Lowest Quarterly Return, Date Mar. 31, 2020