v3.25.2
Shareholder Report, Average Annual Return (Details)
 12 Months Ended 60 Months Ended 120 Months Ended
Jul. 31, 2025
Jul. 31, 2025
Jul. 31, 2025
C000006902 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name C with CDSC (1% for 12 months)    
Average Annual Return, Percent [1] 6.16% 0.97% 2.57%
C000006901 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name B with CDSC (declining over six years from 4% to 0%)    
Average Annual Return, Percent [2] 3.15% 0.65% 2.58%
C000006900 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name A with initial sales charge (4.25%)    
Average Annual Return, Percent 3.38% 0.84% 2.90%
Without Sales Load [Member] | C000034483 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name R6 without sales charge    
Average Annual Return, Percent 8.35% 2.09% 3.70%
Without Sales Load [Member] | C000074227 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name R4 without sales charge    
Average Annual Return, Percent 8.23% 1.99% 3.60%
Without Sales Load [Member] | C000074226 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name R3 without sales charge    
Average Annual Return, Percent 7.96% 1.73% 3.34%
Without Sales Load [Member] | C000074225 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name R2 without sales charge    
Average Annual Return, Percent 7.69% 1.48% 3.08%
Without Sales Load [Member] | C000074224 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name R1 without sales charge    
Average Annual Return, Percent 7.24% 0.99% 2.58%
Without Sales Load [Member] | C000006903 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name I without sales charge    
Average Annual Return, Percent 8.15% 1.98% 3.59%
Without Sales Load [Member] | C000006902 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name C without sales charge    
Average Annual Return, Percent 7.16% 0.97% 2.57%
Without Sales Load [Member] | C000006901 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name B without sales charge    
Average Annual Return, Percent 7.15% 0.97% 2.58%
Without Sales Load [Member] | C000006900 [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name A without sales charge    
Average Annual Return, Percent 7.96% 1.72% 3.34%
JPMorgan Emerging Markets Bond Index Global Diversified [Member]      
Average Annual Return [Line Items]      
Line Graph and Table Measure Name JPMorgan Emerging Markets Bond Index Global Diversified    
Average Annual Return, Percent [3] 9.32% 1.31% 3.61%
[1] Assuming redemption at the end of the applicable period.
[2] Assuming redemption at the end of the applicable period.
[3] Source: FactSet Research Systems Inc.