Label	Element	Value
Risk Return Abstract	rr_RiskReturnAbstract
Document Type	dei_DocumentType	485BPOS
Period End Date	dei_DocumentPeriodEndDate	Sep. 30, 2021
Registrant Name	dei_EntityRegistrantName	VANGUARD MALVERN FUNDS
CIK	dei_EntityCentralIndexKey	0000836906
Amendment Flag	dei_AmendmentFlag	false
Document Created Date	dei_DocumentCreationDate	Jan. 28, 2022
Document Effective Date	dei_DocumentEffectiveDate	Jan. 31, 2022
Prospectus Date	rr_ProspectusDate	Jan. 31, 2022
Entity Inv Company Type	dei_EntityInvCompanyType	N-1A