Document and Entity Information	Total
Prospectus:
Document Type	485BPOS
Document Period End Date	Apr. 30, 2018
Registrant Name	DREYFUS MUNICIPAL BOND OPPORTUNITY FUND
Central Index Key	0000797923
Amendment Flag	false
Document Creation Date	Aug. 28, 2018
Document Effective Date	Aug. 31, 2018
Prospectus Date	Aug. 31, 2018
DREYFUS MUNICIPAL BOND OPPORTUNITY FUND \| Class A
Prospectus:
Trading Symbol	PTEBX
DREYFUS MUNICIPAL BOND OPPORTUNITY FUND \| Class C
Prospectus:
Trading Symbol	DMBCX
DREYFUS MUNICIPAL BOND OPPORTUNITY FUND \| Class Z
Prospectus:
Trading Symbol	DMBZX
DREYFUS MUNICIPAL BOND OPPORTUNITY FUND \| Class Y
Prospectus:
Trading Symbol	DMBYX
DREYFUS MUNICIPAL BOND OPPORTUNITY FUND \| Class I
Prospectus:
Trading Symbol	DMBVX

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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
-Publisher SEC
-Name Regulation 12B
-Number 240
-Section 12b
-Subsection 1

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