000001 - Document - Document and Entity Information link:presentationLink link:definitionLink link:calculationLink 020000 - Document - Risk/Return Summary {Unlabeled} - MFS Alabama Municipal Bond Fund link:presentationLink link:definitionLink link:calculationLink 020001 - Schedule - Shareholder Fees link:presentationLink link:definitionLink link:calculationLink 020002 - Schedule - Annual Fund Operating Expenses link:presentationLink link:definitionLink link:calculationLink 020003 - Schedule - Expense Example {Transposed} link:presentationLink link:definitionLink link:calculationLink 020004 - Schedule - Expense Example No Redemption {Transposed} link:presentationLink link:definitionLink link:calculationLink 020005 - Schedule - Annual Total Returns [Bar Chart] link:presentationLink link:definitionLink link:calculationLink 020006 - Schedule - Average Annual Returns {Transposed} link:presentationLink link:definitionLink link:calculationLink 020008 - Document - Risk/Return Summary {Unlabeled} - MFS Arkansas Municipal Bond Fund link:presentationLink link:definitionLink link:calculationLink 020009 - Schedule - Shareholder Fees link:presentationLink link:definitionLink link:calculationLink 020010 - Schedule - Annual Fund Operating Expenses link:presentationLink link:definitionLink link:calculationLink 020011 - Schedule - Expense Example {Transposed} link:presentationLink link:definitionLink link:calculationLink 020012 - Schedule - Expense Example No Redemption {Transposed} link:presentationLink link:definitionLink link:calculationLink 020013 - Schedule - Annual Total Returns [Bar Chart] link:presentationLink link:definitionLink link:calculationLink 020014 - Schedule - Average Annual Returns {Transposed} link:presentationLink link:definitionLink link:calculationLink 020016 - Document - Risk/Return Summary {Unlabeled} - MFS California Municipal Bond Fund link:presentationLink link:definitionLink link:calculationLink 020017 - Schedule - Shareholder Fees link:presentationLink link:definitionLink link:calculationLink 020018 - Schedule - Annual Fund Operating Expenses link:presentationLink link:definitionLink link:calculationLink 020019 - Schedule - Expense Example {Transposed} link:presentationLink link:definitionLink link:calculationLink 020020 - Schedule - Expense Example No Redemption {Transposed} link:presentationLink link:definitionLink link:calculationLink 020021 - Schedule - Annual Total Returns [Bar Chart] link:presentationLink link:definitionLink link:calculationLink 020022 - Schedule - Average Annual Returns {Transposed} link:presentationLink link:definitionLink link:calculationLink 020024 - Document - Risk/Return Summary {Unlabeled} - MFS Georgia Municipal Bond Fund link:presentationLink link:definitionLink link:calculationLink 020025 - Schedule - Shareholder Fees link:presentationLink link:definitionLink link:calculationLink 020026 - Schedule - Annual Fund Operating Expenses link:presentationLink link:definitionLink link:calculationLink 020027 - Schedule - Expense Example {Transposed} link:presentationLink link:definitionLink link:calculationLink 020028 - Schedule - Expense Example No Redemption {Transposed} link:presentationLink link:definitionLink link:calculationLink 020029 - Schedule - Annual Total Returns [Bar Chart] link:presentationLink link:definitionLink link:calculationLink 020030 - Schedule - Average Annual Returns {Transposed} link:presentationLink link:definitionLink link:calculationLink 020032 - Document - Risk/Return Summary {Unlabeled} - MFS Maryland Municipal Bond Fund link:presentationLink link:definitionLink link:calculationLink 020033 - Schedule - Shareholder Fees link:presentationLink link:definitionLink link:calculationLink 020034 - Schedule - Annual Fund Operating Expenses link:presentationLink link:definitionLink link:calculationLink 020035 - Schedule - Expense Example {Transposed} link:presentationLink link:definitionLink link:calculationLink 020036 - Schedule - Expense Example No Redemption {Transposed} link:presentationLink link:definitionLink link:calculationLink 020037 - Schedule - Annual Total Returns [Bar Chart] link:presentationLink link:definitionLink link:calculationLink 020038 - Schedule - Average Annual Returns {Transposed} link:presentationLink link:definitionLink link:calculationLink 020040 - Document - Risk/Return Summary {Unlabeled} - MFS Massachusetts Municipal Bond Fund link:presentationLink link:definitionLink link:calculationLink 020041 - Schedule - Shareholder Fees link:presentationLink link:definitionLink link:calculationLink 020042 - Schedule - Annual Fund Operating Expenses link:presentationLink link:definitionLink link:calculationLink 020043 - Schedule - Expense Example {Transposed} link:presentationLink link:definitionLink link:calculationLink 020044 - Schedule - Expense Example No Redemption {Transposed} link:presentationLink link:definitionLink link:calculationLink 020045 - Schedule - Annual Total Returns [Bar Chart] link:presentationLink link:definitionLink link:calculationLink 020046 - Schedule - Average Annual Returns {Transposed} link:presentationLink link:definitionLink link:calculationLink 020048 - Document - Risk/Return Summary {Unlabeled} - MFS Mississippi Municipal Bond Fund link:presentationLink link:definitionLink link:calculationLink 020049 - Schedule - Shareholder Fees link:presentationLink link:definitionLink link:calculationLink 020050 - Schedule - Annual Fund Operating Expenses link:presentationLink link:definitionLink link:calculationLink 020051 - Schedule - Expense Example {Transposed} link:presentationLink link:definitionLink link:calculationLink 020052 - Schedule - Expense Example No Redemption {Transposed} link:presentationLink link:definitionLink link:calculationLink 020053 - Schedule - Annual Total Returns [Bar Chart] link:presentationLink link:definitionLink link:calculationLink 020054 - Schedule - Average Annual Returns {Transposed} link:presentationLink link:definitionLink link:calculationLink 020056 - Document - Risk/Return Summary {Unlabeled} - MFS New York Municipal Bond Fund link:presentationLink link:definitionLink link:calculationLink 020057 - Schedule - Shareholder Fees link:presentationLink link:definitionLink link:calculationLink 020058 - Schedule - Annual Fund Operating Expenses link:presentationLink link:definitionLink link:calculationLink 020059 - Schedule - Expense Example {Transposed} link:presentationLink link:definitionLink link:calculationLink 020060 - Schedule - Expense Example No Redemption {Transposed} link:presentationLink link:definitionLink link:calculationLink 020061 - Schedule - Annual Total Returns [Bar Chart] link:presentationLink link:definitionLink link:calculationLink 020062 - Schedule - Average Annual Returns {Transposed} link:presentationLink link:definitionLink link:calculationLink 020064 - Document - Risk/Return Summary {Unlabeled} - MFS North Carolina Municipal Bond Fund link:presentationLink link:definitionLink link:calculationLink 020065 - Schedule - Shareholder Fees link:presentationLink link:definitionLink link:calculationLink 020066 - Schedule - Annual Fund Operating Expenses link:presentationLink link:definitionLink link:calculationLink 020067 - Schedule - Expense Example {Transposed} link:presentationLink link:definitionLink link:calculationLink 020068 - Schedule - Expense Example No Redemption {Transposed} link:presentationLink link:definitionLink link:calculationLink 020069 - Schedule - Annual Total Returns [Bar Chart] link:presentationLink link:definitionLink link:calculationLink 020070 - Schedule - Average Annual Returns {Transposed} link:presentationLink link:definitionLink link:calculationLink 020072 - Document - Risk/Return Summary {Unlabeled} - MFS Pennsylvania Municipal Bond Fund link:presentationLink link:definitionLink link:calculationLink 020073 - Schedule - Shareholder Fees link:presentationLink link:definitionLink link:calculationLink 020074 - Schedule - Annual Fund Operating Expenses link:presentationLink link:definitionLink link:calculationLink 020075 - Schedule - Expense Example {Transposed} link:presentationLink link:definitionLink link:calculationLink 020076 - Schedule - Expense Example No Redemption {Transposed} link:presentationLink link:definitionLink link:calculationLink 020077 - Schedule - Annual Total Returns [Bar Chart] link:presentationLink link:definitionLink link:calculationLink 020078 - Schedule - Average Annual Returns {Transposed} link:presentationLink link:definitionLink link:calculationLink 020080 - Document - Risk/Return Summary {Unlabeled} - MFS South Carolina Municipal Bond Fund link:presentationLink link:definitionLink link:calculationLink 020081 - Schedule - Shareholder Fees link:presentationLink link:definitionLink link:calculationLink 020082 - Schedule - Annual Fund Operating Expenses link:presentationLink link:definitionLink link:calculationLink 020083 - Schedule - Expense Example {Transposed} link:presentationLink link:definitionLink link:calculationLink 020084 - Schedule - Expense Example No Redemption {Transposed} link:presentationLink link:definitionLink link:calculationLink 020085 - Schedule - Annual Total Returns [Bar Chart] link:presentationLink link:definitionLink link:calculationLink 020086 - Schedule - Average Annual Returns {Transposed} link:presentationLink link:definitionLink link:calculationLink 020088 - Document - Risk/Return Summary {Unlabeled} - MFS Tennessee Municipal Bond Fund link:presentationLink link:definitionLink link:calculationLink 020089 - Schedule - Shareholder Fees link:presentationLink link:definitionLink link:calculationLink 020090 - Schedule - Annual Fund Operating Expenses link:presentationLink link:definitionLink link:calculationLink 020091 - Schedule - Expense Example {Transposed} link:presentationLink link:definitionLink link:calculationLink 020092 - Schedule - Expense Example No Redemption {Transposed} link:presentationLink link:definitionLink link:calculationLink 020093 - Schedule - Annual Total Returns [Bar Chart] link:presentationLink link:definitionLink link:calculationLink 020094 - Schedule - Average Annual Returns {Transposed} link:presentationLink link:definitionLink link:calculationLink 020096 - Document - Risk/Return Summary {Unlabeled} - MFS Virginia Municipal Bond Fund link:presentationLink link:definitionLink link:calculationLink 020097 - Schedule - Shareholder Fees link:presentationLink link:definitionLink link:calculationLink 020098 - Schedule - Annual Fund Operating Expenses link:presentationLink link:definitionLink link:calculationLink 020099 - Schedule - Expense Example {Transposed} link:presentationLink link:definitionLink link:calculationLink 020100 - Schedule - Expense Example No Redemption {Transposed} link:presentationLink link:definitionLink link:calculationLink 020101 - Schedule - Annual Total Returns [Bar Chart] link:presentationLink link:definitionLink link:calculationLink 020102 - Schedule - Average Annual Returns {Transposed} link:presentationLink link:definitionLink link:calculationLink 020104 - Document - Risk/Return Summary {Unlabeled} - MFS West Virginia Municipal Bond Fund link:presentationLink link:definitionLink link:calculationLink 020105 - Schedule - Shareholder Fees link:presentationLink link:definitionLink link:calculationLink 020106 - Schedule - Annual Fund Operating Expenses link:presentationLink link:definitionLink link:calculationLink 020107 - Schedule - Expense Example {Transposed} link:presentationLink link:definitionLink link:calculationLink 020108 - Schedule - Expense Example No Redemption {Transposed} link:presentationLink link:definitionLink link:calculationLink 020109 - Schedule - Annual Total Returns [Bar Chart] link:presentationLink link:definitionLink link:calculationLink 020110 - Schedule - Average Annual Returns {Transposed} link:presentationLink link:definitionLink link:calculationLink 020112 - Document - Risk/Return Summary {Unlabeled} - Class A, B, C, and I Prospectus - MFS Municipal Income Fund (A, B, C, I) link:presentationLink link:definitionLink link:calculationLink 020113 - Schedule - Shareholder Fees link:presentationLink link:definitionLink link:calculationLink 020114 - Schedule - Annual Fund Operating Expenses link:presentationLink link:definitionLink link:calculationLink 020115 - Schedule - Expense Example {Transposed} link:presentationLink link:definitionLink link:calculationLink 020116 - Schedule - Expense Example No Redemption {Transposed} link:presentationLink link:definitionLink link:calculationLink 020117 - Schedule - Annual Total Returns [Bar Chart] link:presentationLink link:definitionLink link:calculationLink 020118 - Schedule - Average Annual Returns {Transposed} link:presentationLink link:definitionLink link:calculationLink 020120 - Document - Risk/Return Summary {Unlabeled} - Class A1 and B1 Prospectus - MFS Municipal Income Fund (A1, B1) link:presentationLink link:definitionLink link:calculationLink 020121 - Schedule - Shareholder Fees link:presentationLink link:definitionLink link:calculationLink 020122 - Schedule - Annual Fund Operating Expenses link:presentationLink link:definitionLink link:calculationLink 020123 - Schedule - Expense Example {Transposed} link:presentationLink link:definitionLink link:calculationLink 020124 - Schedule - Expense Example No Redemption {Transposed} link:presentationLink link:definitionLink link:calculationLink 020125 - Schedule - Annual Total Returns [Bar Chart] link:presentationLink link:definitionLink link:calculationLink 020126 - Schedule - Average Annual Returns {Transposed} link:presentationLink link:definitionLink link:calculationLink 020007 - Disclosure - Risk/Return Detail Data {Elements} - MFS Alabama Municipal Bond Fund link:presentationLink link:definitionLink link:calculationLink 020015 - Disclosure - Risk/Return Detail Data {Elements} - MFS Arkansas Municipal Bond Fund link:presentationLink link:definitionLink link:calculationLink 020023 - Disclosure - Risk/Return Detail Data {Elements} - MFS California Municipal Bond Fund link:presentationLink link:definitionLink link:calculationLink 020031 - Disclosure - Risk/Return Detail Data {Elements} - MFS Georgia Municipal Bond Fund link:presentationLink link:definitionLink link:calculationLink 020039 - Disclosure - Risk/Return Detail Data {Elements} - MFS Maryland Municipal Bond Fund link:presentationLink link:definitionLink link:calculationLink 020047 - Disclosure - Risk/Return Detail Data {Elements} - MFS Massachusetts Municipal Bond Fund link:presentationLink link:definitionLink link:calculationLink 020055 - Disclosure - Risk/Return Detail Data {Elements} - MFS Mississippi Municipal Bond Fund link:presentationLink link:definitionLink link:calculationLink 020063 - Disclosure - Risk/Return Detail Data {Elements} - MFS New York Municipal Bond Fund link:presentationLink link:definitionLink link:calculationLink 020071 - Disclosure - Risk/Return Detail Data {Elements} - MFS North Carolina Municipal Bond Fund link:presentationLink link:definitionLink link:calculationLink 020079 - Disclosure - Risk/Return Detail Data {Elements} - MFS Pennsylvania Municipal Bond Fund link:presentationLink link:definitionLink link:calculationLink 020087 - Disclosure - Risk/Return Detail Data {Elements} - MFS South Carolina Municipal Bond Fund link:presentationLink link:definitionLink link:calculationLink 020095 - Disclosure - Risk/Return Detail Data {Elements} - MFS Tennessee Municipal Bond Fund link:presentationLink link:definitionLink link:calculationLink 020103 - Disclosure - Risk/Return Detail Data {Elements} - MFS Virginia Municipal Bond Fund link:presentationLink link:definitionLink link:calculationLink 020111 - Disclosure - Risk/Return Detail Data {Elements} - MFS West Virginia Municipal Bond Fund link:presentationLink link:definitionLink link:calculationLink 020119 - Disclosure - Risk/Return Detail Data {Elements} - Class A, B, C, and I Prospectus - MFS Municipal Income Fund (A, B, C, I) link:presentationLink link:definitionLink link:calculationLink 020127 - Disclosure - Risk/Return Detail Data {Elements} - Class A1 and B1 Prospectus - MFS Municipal Income Fund (A1, B1) link:presentationLink link:definitionLink link:calculationLink