v3.26.1

S000001273 [Member] Shareholder Fees	Mar. 31, 2026 USD ($)
MID CAP INDEX FUND \| MID CAP INDEX FUND
Prospectus [Line Items]
Shareholder Fee, Other	$ 0

X

- References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form N-1A
-Section 1
-Subsection a

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- References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form N-1A
-Section 3
-Subsection instruction
-Paragraph 2

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