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Select Bond Portfolio Average Annual Total Returns
12 Months Ended 60 Months Ended 120 Months Ended
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
Bloomberg® U.S. Aggregate Bond Index(reflects no deduction for fees, expenses or taxes)[Member]      
Prospectus [Line Items]      
Average Annual Return, Percent 7.30% (0.36%) 2.01%
Select Bond Portfolio      
Prospectus [Line Items]      
Average Annual Return, Percent 7.45% (0.19%) 2.25%