Mid Cap Index Fund Average Annual Total Returns |
12 Months Ended | 60 Months Ended | 120 Months Ended |
|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2025 |
Dec. 31, 2025 |
|
| Russell 3000® Index (reflects no deduction for fees, expenses or taxes)[Member] | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 17.15% | 13.15% | 14.29% |
| S&P MidCap 400® Index (reflects no deduction for fees, expenses or taxes)[Member] | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 7.50% | 9.12% | 10.72% |
| None | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 6.95% | 8.68% | 10.34% |