010000 - Document - Document and Entity Information {Elements}
link:presentationLink
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020102 - Disclosure - Risk/Return Detail Data (MFS Core Bond Fund) {Elements}
link:presentationLink
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020101 - Schedule - Risk Table {Transposed}
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020104 - Disclosure - Risk/Return Detail Data (MFS Lifetime Income Fund) {Elements}
link:presentationLink
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020101 - Schedule - Risk Table {Transposed}
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020106 - Disclosure - Risk/Return Detail Data (MFS Lifetime 2030 Fund) {Elements}
link:presentationLink
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020101 - Schedule - Risk Table {Transposed}
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020108 - Disclosure - Risk/Return Detail Data (MFS Lifetime 2035 Fund) {Elements}
link:presentationLink
link:calculationLink
link:definitionLink
020101 - Schedule - Risk Table {Transposed}
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020110 - Disclosure - Risk/Return Detail Data (MFS Lifetime 2040 Fund) {Elements}
link:presentationLink
link:calculationLink
link:definitionLink
020101 - Schedule - Risk Table {Transposed}
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020112 - Disclosure - Risk/Return Detail Data (MFS Lifetime 2045 Fund) {Elements}
link:presentationLink
link:calculationLink
link:definitionLink
020101 - Schedule - Risk Table {Transposed}
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020114 - Disclosure - Risk/Return Detail Data (MFS Lifetime 2050 Fund) {Elements}
link:presentationLink
link:calculationLink
link:definitionLink
020101 - Schedule - Risk Table {Transposed}
link:presentationLink
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020116 - Disclosure - Risk/Return Detail Data (MFS Lifetime 2055 Fund) {Elements}
link:presentationLink
link:calculationLink
link:definitionLink
020101 - Schedule - Risk Table {Transposed}
link:presentationLink
link:calculationLink
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020118 - Disclosure - Risk/Return Detail Data (MFS Lifetime 2060 Fund) {Elements}
link:presentationLink
link:calculationLink
link:definitionLink
020101 - Schedule - Risk Table {Transposed}
link:presentationLink
link:calculationLink
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020120 - Disclosure - Risk/Return Detail Data (MFS Lifetime 2065 Fund) {Elements}
link:presentationLink
link:calculationLink
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020101 - Schedule - Risk Table {Transposed}
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010004 - Schedule - Investment Risks {Unlabeled}
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