Label	Element	Value
Risk/Return:	rr_RiskReturnAbstract
Document Type	dei_DocumentType	497
Period End Date	dei_DocumentPeriodEndDate	Mar. 16, 2020
Registrant Name	dei_EntityRegistrantName	CASH ACCOUNT TRUST
CIK	dei_EntityCentralIndexKey	0000858372
Amendment Flag	dei_AmendmentFlag	false
Document Created Date	dei_DocumentCreationDate	Mar. 16, 2020
Effective Date	dei_DocumentEffectiveDate	Mar. 16, 2020
Prospectus Date	rr_ProspectusDate	Mar. 16, 2020
Entity Inv Company Type	dei_EntityInvCompanyType	N-1A