2.4.0.8 HtmlAndXml 195 96 1 true 119 0 false 2 false false R1.htm 000000 - Document - Document and Entity Information Sheet http://www.northernfunds.com/role/DocumentDocumentandEntityInformation Document and Entity Information R1.xml false true R2.htm 000011 - Document - Risk/Return Summary {Unlabeled} - NORTHERN ENHANCED LARGE CAP FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNENHANCEDLARGECAPFUND Risk/Return Summary - NORTHERN ENHANCED LARGE CAP FUND R2.xml false false R8.htm 000019 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN ENHANCED LARGE CAP FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNENHANCEDLARGECAPFUND Risk/Return Detail Data - NORTHERN ENHANCED LARGE CAP FUND R8.xml false true R9.htm 000021 - Document - Risk/Return Summary {Unlabeled} - NORTHERN INCOME EQUITY FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNINCOMEEQUITYFUND Risk/Return Summary - NORTHERN INCOME EQUITY FUND R9.xml false false R15.htm 000029 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN INCOME EQUITY FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNINCOMEEQUITYFUND Risk/Return Detail Data - NORTHERN INCOME EQUITY FUND R15.xml false true R16.htm 000031 - Document - Risk/Return Summary {Unlabeled} - NORTHERN INTERNATIONAL EQUITY FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNINTERNATIONALEQUITYFUND Risk/Return Summary - NORTHERN INTERNATIONAL EQUITY FUND R16.xml false false R22.htm 000039 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN INTERNATIONAL EQUITY FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNINTERNATIONALEQUITYFUND Risk/Return Detail Data - NORTHERN INTERNATIONAL EQUITY FUND R22.xml false true R23.htm 000041 - Document - Risk/Return Summary {Unlabeled} - NORTHERN LARGE CAP EQUITY FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNLARGECAPEQUITYFUND Risk/Return Summary - NORTHERN LARGE CAP EQUITY FUND R23.xml false false R29.htm 000049 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN LARGE CAP EQUITY FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNLARGECAPEQUITYFUND Risk/Return Detail Data - NORTHERN LARGE CAP EQUITY FUND R29.xml false true R30.htm 000051 - Document - Risk/Return Summary {Unlabeled} - NORTHERN LARGE CAP GROWTH FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNLARGECAPGROWTHFUND Risk/Return Summary - NORTHERN LARGE CAP GROWTH FUND R30.xml false false R36.htm 000059 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN LARGE CAP GROWTH FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNLARGECAPGROWTHFUND Risk/Return Detail Data - NORTHERN LARGE CAP GROWTH FUND R36.xml false true R37.htm 000061 - Document - Risk/Return Summary {Unlabeled} - NORTHERN LARGE CAP VALUE FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNLARGECAPVALUEFUND Risk/Return Summary - NORTHERN LARGE CAP VALUE FUND R37.xml false false R43.htm 000069 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN LARGE CAP VALUE FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNLARGECAPVALUEFUND Risk/Return Detail Data - NORTHERN LARGE CAP VALUE FUND R43.xml false true R44.htm 000071 - Document - Risk/Return Summary {Unlabeled} - NORTHERN SMALL CAP CORE FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNSMALLCAPCOREFUND Risk/Return Summary - NORTHERN SMALL CAP CORE FUND R44.xml false false R50.htm 000079 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN SMALL CAP CORE FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNSMALLCAPCOREFUND Risk/Return Detail Data - NORTHERN SMALL CAP CORE FUND R50.xml false true R51.htm 000081 - Document - Risk/Return Summary {Unlabeled} - NORTHERN SMALL CAP VALUE FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNSMALLCAPVALUEFUND Risk/Return Summary - NORTHERN SMALL CAP VALUE FUND R51.xml false false R57.htm 000089 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN SMALL CAP VALUE FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNSMALLCAPVALUEFUND Risk/Return Detail Data - NORTHERN SMALL CAP VALUE FUND R57.xml false true R58.htm 000091 - Document - Risk/Return Summary {Unlabeled} - NORTHERN TECHNOLOGY FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNTECHNOLOGYFUND Risk/Return Summary - NORTHERN TECHNOLOGY FUND R58.xml false false R64.htm 000099 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN TECHNOLOGY FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNTECHNOLOGYFUND Risk/Return Detail Data - NORTHERN TECHNOLOGY FUND R64.xml false true R65.htm 000101 - Document - Risk/Return Summary {Unlabeled} - NORTHERN GLOBAL TACTICAL ASSET ALLOCATION FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNGLOBALTACTICALASSETALLOCATIONFUND Risk/Return Summary - NORTHERN GLOBAL TACTICAL ASSET ALLOCATION FUND R65.xml false false R71.htm 000109 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN GLOBAL TACTICAL ASSET ALLOCATION FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNGLOBALTACTICALASSETALLOCATIONFUND Risk/Return Detail Data - NORTHERN GLOBAL TACTICAL ASSET ALLOCATION FUND R71.xml false true R72.htm 000111 - Document - Risk/Return Summary {Unlabeled} - NORTHERN EMERGING MARKETS EQUITY INDEX FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNEMERGINGMARKETSEQUITYINDEXFUND Risk/Return Summary - NORTHERN EMERGING MARKETS EQUITY INDEX FUND R72.xml false false R78.htm 000119 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN EMERGING MARKETS EQUITY INDEX FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNEMERGINGMARKETSEQUITYINDEXFUND Risk/Return Detail Data - NORTHERN EMERGING MARKETS EQUITY INDEX FUND R78.xml false true R79.htm 000121 - Document - Risk/Return Summary {Unlabeled} - NORTHERN GLOBAL REAL ESTATE INDEX FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNGLOBALREALESTATEINDEXFUND Risk/Return Summary - NORTHERN GLOBAL REAL ESTATE INDEX FUND R79.xml false false R85.htm 000129 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN GLOBAL REAL ESTATE INDEX FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNGLOBALREALESTATEINDEXFUND Risk/Return Detail Data - NORTHERN GLOBAL REAL ESTATE INDEX FUND R85.xml false true R86.htm 000131 - Document - Risk/Return Summary {Unlabeled} - NORTHERN GLOBAL SUSTAINABILITY INDEX FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNGLOBALSUSTAINABILITYINDEXFUND Risk/Return Summary - NORTHERN GLOBAL SUSTAINABILITY INDEX FUND R86.xml false false R92.htm 000139 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN GLOBAL SUSTAINABILITY INDEX FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNGLOBALSUSTAINABILITYINDEXFUND Risk/Return Detail Data - NORTHERN GLOBAL SUSTAINABILITY INDEX FUND R92.xml false true R93.htm 000141 - Document - Risk/Return Summary {Unlabeled} - NORTHERN INTERNATIONAL EQUITY INDEX FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNINTERNATIONALEQUITYINDEXFUND Risk/Return Summary - NORTHERN INTERNATIONAL EQUITY INDEX FUND R93.xml false false R99.htm 000149 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN INTERNATIONAL EQUITY INDEX FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNINTERNATIONALEQUITYINDEXFUND Risk/Return Detail Data - NORTHERN INTERNATIONAL EQUITY INDEX FUND R99.xml false true R100.htm 000151 - Document - Risk/Return Summary {Unlabeled} - NORTHERN MID CAP INDEX FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNMIDCAPINDEXFUND Risk/Return Summary - NORTHERN MID CAP INDEX FUND R100.xml false false R106.htm 000159 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN MID CAP INDEX FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNMIDCAPINDEXFUND Risk/Return Detail Data - NORTHERN MID CAP INDEX FUND R106.xml false true R107.htm 000161 - Document - Risk/Return Summary {Unlabeled} - NORTHERN SMALL CAP INDEX FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNSMALLCAPINDEXFUND Risk/Return Summary - NORTHERN SMALL CAP INDEX FUND R107.xml false false R113.htm 000169 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN SMALL CAP INDEX FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNSMALLCAPINDEXFUND Risk/Return Detail Data - NORTHERN SMALL CAP INDEX FUND R113.xml false true R114.htm 000171 - Document - Risk/Return Summary {Unlabeled} - NORTHERN STOCK INDEX FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNSTOCKINDEXFUND Risk/Return Summary - NORTHERN STOCK INDEX FUND R114.xml false false R120.htm 000179 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN STOCK INDEX FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNSTOCKINDEXFUND Risk/Return Detail Data - NORTHERN STOCK INDEX FUND R120.xml false true R121.htm 000181 - Document - Risk/Return Summary {Unlabeled} - NORTHERN BOND INDEX FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNBONDINDEXFUND Risk/Return Summary - NORTHERN BOND INDEX FUND R121.xml false false R127.htm 000189 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN BOND INDEX FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNBONDINDEXFUND Risk/Return Detail Data - NORTHERN BOND INDEX FUND R127.xml false true R128.htm 000191 - Document - Risk/Return Summary {Unlabeled} - NORTHERN CORE BOND FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNCOREBONDFUND Risk/Return Summary - NORTHERN CORE BOND FUND R128.xml false false R134.htm 000199 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN CORE BOND FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNCOREBONDFUND Risk/Return Detail Data - NORTHERN CORE BOND FUND R134.xml false true R135.htm 000201 - Document - Risk/Return Summary {Unlabeled} - NORTHERN FIXED INCOME FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNFIXEDINCOMEFUND Risk/Return Summary - NORTHERN FIXED INCOME FUND R135.xml false false R141.htm 000209 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN FIXED INCOME FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNFIXEDINCOMEFUND Risk/Return Detail Data - NORTHERN FIXED INCOME FUND R141.xml false true R142.htm 000211 - Document - Risk/Return Summary {Unlabeled} - NORTHERN HIGH YIELD FIXED INCOME FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNHIGHYIELDFIXEDINCOMEFUND Risk/Return Summary - NORTHERN HIGH YIELD FIXED INCOME FUND R142.xml false false R148.htm 000219 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN HIGH YIELD FIXED INCOME FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNHIGHYIELDFIXEDINCOMEFUND Risk/Return Detail Data - NORTHERN HIGH YIELD FIXED INCOME FUND R148.xml false true R149.htm 000221 - Document - Risk/Return Summary {Unlabeled} - NORTHERN SHORT BOND FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNSHORTBONDFUND Risk/Return Summary - NORTHERN SHORT BOND FUND R149.xml false false R155.htm 000229 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN SHORT BOND FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNSHORTBONDFUND Risk/Return Detail Data - NORTHERN SHORT BOND FUND R155.xml false true R156.htm 000231 - Document - Risk/Return Summary {Unlabeled} - NORTHERN SHORT-INTERMEDIATE U.S. GOVERNMENT FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNSHORT-INTERMEDIATEU.S.GOVERNMENTFUND Risk/Return Summary - NORTHERN SHORT-INTERMEDIATE U.S. GOVERNMENT FUND R156.xml false false R162.htm 000239 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN SHORT-INTERMEDIATE U.S. GOVERNMENT FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNSHORT-INTERMEDIATEU.S.GOVERNMENTFUND Risk/Return Detail Data - NORTHERN SHORT-INTERMEDIATE U.S. GOVERNMENT FUND R162.xml false true R163.htm 000241 - Document - Risk/Return Summary {Unlabeled} - NORTHERN TAX-ADVANTAGED ULTRA-SHORT FIXED INCOME FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNTAX-ADVANTAGEDULTRA-SHORTFIXEDINCOMEFUND Risk/Return Summary - NORTHERN TAX-ADVANTAGED ULTRA-SHORT FIXED INCOME FUND R163.xml false false R169.htm 000249 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN TAX-ADVANTAGED ULTRA-SHORT FIXED INCOME FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNTAX-ADVANTAGEDULTRA-SHORTFIXEDINCOMEFUND Risk/Return Detail Data - NORTHERN TAX-ADVANTAGED ULTRA-SHORT FIXED INCOME FUND R169.xml false true R170.htm 000251 - Document - Risk/Return Summary {Unlabeled} - NORTHERN ULTRA-SHORT FIXED INCOME FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNULTRA-SHORTFIXEDINCOMEFUND Risk/Return Summary - NORTHERN ULTRA-SHORT FIXED INCOME FUND R170.xml false false R176.htm 000259 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN ULTRA-SHORT FIXED INCOME FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNULTRA-SHORTFIXEDINCOMEFUND Risk/Return Detail Data - NORTHERN ULTRA-SHORT FIXED INCOME FUND R176.xml false true R177.htm 000261 - Document - Risk/Return Summary {Unlabeled} - NORTHERN U.S. GOVERNMENT FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNU.S.GOVERNMENTFUND Risk/Return Summary - NORTHERN U.S. GOVERNMENT FUND R177.xml false false R183.htm 000269 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN U.S. GOVERNMENT FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNU.S.GOVERNMENTFUND Risk/Return Detail Data - NORTHERN U.S. GOVERNMENT FUND R183.xml false true R184.htm 000271 - Document - Risk/Return Summary {Unlabeled} - NORTHERN U.S.TREASURY INDEX FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNU.S.TREASURYINDEXFUND Risk/Return Summary - NORTHERN U.S.TREASURY INDEX FUND R184.xml false false R190.htm 000279 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN U.S.TREASURY INDEX FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNU.S.TREASURYINDEXFUND Risk/Return Detail Data - NORTHERN U.S.TREASURY INDEX FUND R190.xml false true R191.htm 000281 - Document - Risk/Return Summary {Unlabeled} - NORTHERN ARIZONA TAX-EXEMPT FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNARIZONATAX-EXEMPTFUND Risk/Return Summary - NORTHERN ARIZONA TAX-EXEMPT FUND R191.xml false false R197.htm 000289 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN ARIZONA TAX-EXEMPT FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNARIZONATAX-EXEMPTFUND Risk/Return Detail Data - NORTHERN ARIZONA TAX-EXEMPT FUND R197.xml false true R198.htm 000291 - Document - Risk/Return Summary {Unlabeled} - NORTHERN CALIFORNIA INTERMEDIATE TAX-EXEMPT FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNCALIFORNIAINTERMEDIATETAX-EXEMPTFUND Risk/Return Summary - NORTHERN CALIFORNIA INTERMEDIATE TAX-EXEMPT FUND R198.xml false false R204.htm 000299 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN CALIFORNIA INTERMEDIATE TAX-EXEMPT FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNCALIFORNIAINTERMEDIATETAX-EXEMPTFUND Risk/Return Detail Data - NORTHERN CALIFORNIA INTERMEDIATE TAX-EXEMPT FUND R204.xml false true R205.htm 000301 - Document - Risk/Return Summary {Unlabeled} - NORTHERN CALIFORNIA TAX-EXEMPT FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNCALIFORNIATAX-EXEMPTFUND Risk/Return Summary - NORTHERN CALIFORNIA TAX-EXEMPT FUND R205.xml false false R211.htm 000309 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN CALIFORNIA TAX-EXEMPT FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNCALIFORNIATAX-EXEMPTFUND Risk/Return Detail Data - NORTHERN CALIFORNIA TAX-EXEMPT FUND R211.xml false true R212.htm 000311 - Document - Risk/Return Summary {Unlabeled} - NORTHERN HIGH YIELD MUNICIPAL FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNHIGHYIELDMUNICIPALFUND Risk/Return Summary - NORTHERN HIGH YIELD MUNICIPAL FUND R212.xml false false R218.htm 000319 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN HIGH YIELD MUNICIPAL FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNHIGHYIELDMUNICIPALFUND Risk/Return Detail Data - NORTHERN HIGH YIELD MUNICIPAL FUND R218.xml false true R219.htm 000321 - Document - Risk/Return Summary {Unlabeled} - NORTHERN INTERMEDIATE TAX-EXEMPT FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNINTERMEDIATETAX-EXEMPTFUND Risk/Return Summary - NORTHERN INTERMEDIATE TAX-EXEMPT FUND R219.xml false false R225.htm 000329 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN INTERMEDIATE TAX-EXEMPT FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNINTERMEDIATETAX-EXEMPTFUND Risk/Return Detail Data - NORTHERN INTERMEDIATE TAX-EXEMPT FUND R225.xml false true R226.htm 000331 - Document - Risk/Return Summary {Unlabeled} - NORTHERN SHORT-INTERMEDIATE TAX-EXEMPT FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNSHORT-INTERMEDIATETAX-EXEMPTFUND Risk/Return Summary - NORTHERN SHORT-INTERMEDIATE TAX-EXEMPT FUND R226.xml false false R232.htm 000339 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN SHORT-INTERMEDIATE TAX-EXEMPT FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNSHORT-INTERMEDIATETAX-EXEMPTFUND Risk/Return Detail Data - NORTHERN SHORT-INTERMEDIATE TAX-EXEMPT FUND R232.xml false true R233.htm 000341 - Document - Risk/Return Summary {Unlabeled} - NORTHERN TAX-EXEMPT FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNTAX-EXEMPTFUND Risk/Return Summary - NORTHERN TAX-EXEMPT FUND R233.xml false false R239.htm 000349 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN TAX-EXEMPT FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNTAX-EXEMPTFUND Risk/Return Detail Data - NORTHERN TAX-EXEMPT FUND R239.xml false true R240.htm 000351 - Document - Risk/Return Summary {Unlabeled} - NORTHERN CALIFORNIA MUNICIPAL MONEY MARKET FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNCALIFORNIAMUNICIPALMONEYMARKETFUND Risk/Return Summary - NORTHERN CALIFORNIA MUNICIPAL MONEY MARKET FUND R240.xml false false R246.htm 000359 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN CALIFORNIA MUNICIPAL MONEY MARKET FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNCALIFORNIAMUNICIPALMONEYMARKETFUND Risk/Return Detail Data - NORTHERN CALIFORNIA MUNICIPAL MONEY MARKET FUND R246.xml false true R247.htm 000361 - Document - Risk/Return Summary {Unlabeled} - NORTHERN MONEY MARKET FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNMONEYMARKETFUND Risk/Return Summary - NORTHERN MONEY MARKET FUND R247.xml false false R253.htm 000369 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN MONEY MARKET FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNMONEYMARKETFUND Risk/Return Detail Data - NORTHERN MONEY MARKET FUND R253.xml false true R254.htm 000371 - Document - Risk/Return Summary {Unlabeled} - NORTHERN MUNICIPAL MONEY MARKET FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNMUNICIPALMONEYMARKETFUND Risk/Return Summary - NORTHERN MUNICIPAL MONEY MARKET FUND R254.xml false false R260.htm 000379 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN MUNICIPAL MONEY MARKET FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNMUNICIPALMONEYMARKETFUND Risk/Return Detail Data - NORTHERN MUNICIPAL MONEY MARKET FUND R260.xml false true R261.htm 000381 - Document - Risk/Return Summary {Unlabeled} - NORTHERN U.S. GOVERNMENT MONEY MARKET FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNU.S.GOVERNMENTMONEYMARKETFUND Risk/Return Summary - NORTHERN U.S. GOVERNMENT MONEY MARKET FUND R261.xml false false R267.htm 000389 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN U.S. GOVERNMENT MONEY MARKET FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNU.S.GOVERNMENTMONEYMARKETFUND Risk/Return Detail Data - NORTHERN U.S. GOVERNMENT MONEY MARKET FUND R267.xml false true R268.htm 000391 - Document - Risk/Return Summary {Unlabeled} - NORTHERN U.S. GOVERNMENT SELECT MONEY MARKET FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNU.S.GOVERNMENTSELECTMONEYMARKETFUND Risk/Return Summary - NORTHERN U.S. GOVERNMENT SELECT MONEY MARKET FUND R268.xml false false R274.htm 000399 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN U.S. GOVERNMENT SELECT MONEY MARKET FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNU.S.GOVERNMENTSELECTMONEYMARKETFUND Risk/Return Detail Data - NORTHERN U.S. GOVERNMENT SELECT MONEY MARKET FUND R274.xml false true R275.htm 000401 - Document - Risk/Return Summary {Unlabeled} - NORTHERN INVESTORS VARIABLE NAV MONEY MARKET FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNINVESTORSVARIABLENAVMONEYMARKETFUND Risk/Return Summary - NORTHERN INVESTORS VARIABLE NAV MONEY MARKET FUND R275.xml false false R279.htm 000409 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN INVESTORS VARIABLE NAV MONEY MARKET FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNINVESTORSVARIABLENAVMONEYMARKETFUND Risk/Return Detail Data - NORTHERN INVESTORS VARIABLE NAV MONEY MARKET FUND R279.xml false true R280.htm 000411 - Document - Risk/Return Summary {Unlabeled} - NORTHERN INVESTORS VARIABLE NAV AMT-FREE MUNICIPAL MONEY MARKET FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNINVESTORSVARIABLENAVAMT-FREEMUNICIPALMONEYMARKETFUND Risk/Return Summary - NORTHERN INVESTORS VARIABLE NAV AMT-FREE MUNICIPAL MONEY MARKET FUND R280.xml false false R284.htm 000419 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN INVESTORS VARIABLE NAV AMT-FREE MUNICIPAL MONEY MARKET FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNINVESTORSVARIABLENAVAMT-FREEMUNICIPALMONEYMARKETFUND Risk/Return Detail Data - NORTHERN INVESTORS VARIABLE NAV AMT-FREE MUNICIPAL MONEY MARKET FUND R284.xml false true R285.htm 000421 - Document - Risk/Return Summary {Unlabeled} - NORTHERN INVESTORS VARIABLE NAV U.S. GOVERNMENT MONEY MARKET FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNINVESTORSVARIABLENAVU.S.GOVERNMENTMONEYMARKETFUND Risk/Return Summary - NORTHERN INVESTORS VARIABLE NAV U.S. GOVERNMENT MONEY MARKET FUND R285.xml false false R289.htm 000429 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN INVESTORS VARIABLE NAV U.S. GOVERNMENT MONEY MARKET FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNINVESTORSVARIABLENAVU.S.GOVERNMENTMONEYMARKETFUND Risk/Return Detail Data - NORTHERN INVESTORS VARIABLE NAV U.S. GOVERNMENT MONEY MARKET FUND R289.xml false true R290.htm 000431 - Document - Risk/Return Summary {Unlabeled} - NORTHERN INVESTORS VARIABLE NAV TREASURY MONEY MARKET FUND Sheet http://www.northernfunds.com/role/DocumentRiskReturnSummaryUnlabeledNORTHERNINVESTORSVARIABLENAVTREASURYMONEYMARKETFUND Risk/Return Summary - NORTHERN INVESTORS VARIABLE NAV TREASURY MONEY MARKET FUND R290.xml false false R294.htm 000439 - Disclosure - Risk/Return Detail Data {Elements} - NORTHERN INVESTORS VARIABLE NAV TREASURY MONEY MARKET FUND Sheet http://www.northernfunds.com/role/DisclosureRiskReturnDetailDataElementsNORTHERNINVESTORSVARIABLENAVTREASURYMONEYMARKETFUND Risk/Return Detail Data - NORTHERN INVESTORS VARIABLE NAV TREASURY MONEY MARKET FUND R294.xml false false R295.htm 040000 - Disclosure - Risk/Return Detail Data {Elements} Sheet http://xbrl.sec.gov/rr/role/RiskReturnDetailData Risk/Return Detail Data R295.xml true false All Reports Book All Reports nf-20130722.xml nf-20130722.xsd nf-20130722_cal.xml nf-20130722_def.xml nf-20130722_lab.xml nf-20130722_pre.xml BarChart1.jpg BarChart2.jpg BarChart3.jpg BarChart4.jpg BarChart5.jpg BarChart6.jpg BarChart7.jpg BarChart8.jpg BarChart9.jpg BarChart10.jpg BarChart11.jpg BarChart12.jpg BarChart13.jpg BarChart14.jpg BarChart15.jpg BarChart16.jpg BarChart17.jpg BarChart18.jpg BarChart19.jpg BarChart20.jpg BarChart21.jpg BarChart22.jpg BarChart23.jpg BarChart24.jpg BarChart25.jpg BarChart26.jpg BarChart27.jpg BarChart28.jpg BarChart29.jpg BarChart30.jpg BarChart31.jpg BarChart32.jpg BarChart33.jpg BarChart34.jpg BarChart35.jpg BarChart36.jpg BarChart37.jpg BarChart38.jpg BarChart39.jpg true true