XML 17 R1.htm IDEA: XBRL DOCUMENT v3.22.2.2
Label Element Value
Risk Return Abstract rr_RiskReturnAbstract  
Document Type dei_DocumentType 485BPOS
Period End Date dei_DocumentPeriodEndDate Aug. 31, 2022
Registrant Name dei_EntityRegistrantName Prudential National Muni Fund, Inc.
CIK dei_EntityCentralIndexKey 0000314612
Amendment Flag dei_AmendmentFlag false
Document Creation Date dei_DocumentCreationDate Oct. 27, 2022
Effective Date dei_DocumentEffectiveDate Oct. 29, 2022
Prospectus Date rr_ProspectusDate Oct. 29, 2022
Entity Inv Company Type dei_EntityInvCompanyType N-1A
PGIM National Muni Fund | A  
Risk Return Abstract rr_RiskReturnAbstract  
Trading Symbol dei_TradingSymbol PRNMX
PGIM National Muni Fund | C  
Risk Return Abstract rr_RiskReturnAbstract  
Trading Symbol dei_TradingSymbol PNMCX
PGIM National Muni Fund | Z  
Risk Return Abstract rr_RiskReturnAbstract  
Trading Symbol dei_TradingSymbol DNMZX
PGIM National Muni Fund | R6  
Risk Return Abstract rr_RiskReturnAbstract  
Trading Symbol dei_TradingSymbol PNMQX