Short-Term Bond Portfolio Expense Example - Short-Term Bond Portfolio - Short-Term Bond Portfolio	Dec. 31, 2025 USD ($)
Prospectus [Line Items]
Expense Example, with Redemption, 1 Year	$ 41
Expense Example, with Redemption, 3 Years	128
Expense Example, with Redemption, 5 Years	224
Expense Example, with Redemption, 10 Years	$ 505

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