Document and Entity Information	Total
Prospectus:
Document Type	497
Document Period End Date	Nov. 18, 2020
Entity Registrant Name	DREYFUS CASH MANAGEMENT
Entity Central Index Key	0000759667
Entity Inv Company Type	N-1A
Amendment Flag	false
Document Creation Date	Nov. 18, 2020
Document Effective Date	Nov. 18, 2020
Prospectus Date	Jun. 01, 2020
Administrative Shares Prospectus \| DREYFUS CASH MANAGEMENT \| administrative shares
Prospectus:
Trading Symbol	DACXX
Institutional Shares Prospectus \| DREYFUS CASH MANAGEMENT \| Institutional Shares
Prospectus:
Trading Symbol	DICXX
Investor Shares Prospectus \| DREYFUS CASH MANAGEMENT \| Investor Shares
Prospectus:
Trading Symbol	DVCXX

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The date the document was made available and submitted, in CCYY-MM-DD format. The date of submission, date of acceptance by the recipient, and the document effective date are all potentially different.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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