S000010030 [Member] Expense Example - The Bond Fund - Shares	Oct. 31, 2025 USD ($)
Prospectus [Line Items]
Expense Example, with Redemption, 1 Year	$ 42
Expense Example, with Redemption, 3 Years	132
Expense Example, with Redemption, 5 Years	230
Expense Example, with Redemption, 10 Years	$ 518

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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