State Street Small Cap Equity VIS Fund Average Annual Total Returns |
12 Months Ended | 60 Months Ended | 120 Months Ended |
|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2025 |
Dec. 31, 2025 |
|
| Russell 2000 Index (reflects no deduction for fees, expenses or taxes)[Member] | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 12.81% | 6.09% | 9.62% |
| S&P 500 Index (reflects no deduction for fees, expenses or taxes)[Member] | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 17.88% | 14.42% | 14.82% |
| Class 1 | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | (0.25%) | 4.97% | 8.77% |