Annual Total Returns |
Dec. 31, 2025 |
Dec. 31, 2024 |
Dec. 31, 2023 |
Dec. 31, 2022 |
Dec. 31, 2021 |
Dec. 31, 2020 |
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
Dec. 31, 2016 |
|---|---|---|---|---|---|---|---|---|---|---|
| Massachusetts Investors Growth Stock Fund | Class A | ||||||||||
| Prospectus [Line Items] | ||||||||||
| Annual Return [Percent] | 9.88% | 16.33% | 24.08% | (19.24%) | 26.20% | 22.43% | 39.91% | 0.77% | 28.69% | 6.16% |