v3.26.1
Annual Total Returns - Class A
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
MFS Corporate Bond Fund                    
Prospectus [Line Items]                    
Annual Return [Percent] 7.33% 2.77% 8.84% (16.61%) (1.48%) 10.99% 14.41% (3.20%) 6.06% 5.81%
MFS Limited Maturity Fund                    
Prospectus [Line Items]                    
Annual Return [Percent] 5.69% 5.15% 5.94% (4.27%) (0.25%) 4.14% 4.72% 1.17% 1.29% 1.44%
MFS Municipal Limited Maturity Fund                    
Prospectus [Line Items]                    
Annual Return [Percent] 4.95% 2.89% 4.35% (5.28%) 0.71% 3.26% 5.31% 1.28% 3.22% 0.05%
MFS Total Return Bond Fund                    
Prospectus [Line Items]                    
Annual Return [Percent] 7.17% 2.30% 7.06% (13.96%) (1.06%) 8.68% 9.89% (1.28%) 4.08% 3.54%