MFS Research International Portfolio Average Annual Total Returns |
12 Months Ended | 60 Months Ended | 120 Months Ended |
|---|---|---|---|
Dec. 31, 2025 |
Dec. 31, 2025 |
Dec. 31, 2025 |
|
| MSCI EAFE Index (reflects no deduction for mutual fund fees or expenses)[Member] | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 31.22% | 8.92% | 8.18% |
| MSCI All Country World ex-U.S. Index (reflects no deduction for mutual fund fees or expenses)[Member] | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 32.39% | 7.91% | 8.41% |
| Class A | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 22.72% | 5.80% | 7.83% |
| Class B | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 22.41% | 5.54% | 7.57% |
| Class E | |||
| Prospectus [Line Items] | |||
| Average Annual Return, Percent | 22.54% | 5.64% | 7.68% |