Label	Element	Value
BNY Mellon Municipal Opportunities Fund
Risk/Return:	rr_RiskReturnAbstract
Supplement to Prospectus [Text Block]	rr_SupplementToProspectusTextBlock	June 9, 2020 BNY MELLON FUNDS TRUST BNY Mellon Municipal Opportunities Fund Supplement to Current Prospectus
Risk/Return [Heading]	rr_RiskReturnHeading	BNY Mellon Municipal Opportunities Fund
Strategy Narrative [Text Block]	rr_StrategyNarrativeTextBlock	Effective July 9, 2020, the following information supersedes and replaces the information contained in the first and second sentences of the second paragraph of the sections of the Fund's Prospectus entitled "Fund Summary – BNY Mellon Municipal Opportunities Fund - Principal Investment Strategy" and "Fund Details – Goal and Approach – BNY Mellon Municipal Opportunities Fund": The fund invests at least 50% of its assets in fixed-income securities that are rated investment grade (i.e., Baa/BBB or higher) or are the unrated equivalent as determined by BNY Mellon Investment Adviser, Inc. ("BNYM Investment Adviser"). For additional yield, the fund may invest up to 50% of its assets in fixed-income securities that are rated below investment grade ("high yield" or "junk" bonds) or are the unrated equivalent as determined by BNYM Investment Adviser.
Risk Narrative [Text Block]	rr_RiskNarrativeTextBlock	Effective July 9, 2020, the fund may be subject to ETF and other investment company risk as an additional risk that is not anticipated to be a principal risk of investing in the fund.

Narrative Risk Disclosure. A Fund may, in responding to this Item, describe the types of investors for whom the Fund is intended or the types of investment goals that may be consistent with an investment in the Fund.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form
-Number N-1A
-Chapter A
-Section 4
-Subsection b
-Paragraph 1
-Subparagraph i
-Clause instruction

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- References

No definition available.

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- Definition

Risk/Return Summary Investment Objectives/Goals Include the following information, in plain English under rule 421(d) under the Securities Act, in the order and subject matter indicated

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form
-Number N-1A
-Chapter A
-Section 2

+ Details

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- Definition

Principal investment strategies of the Fund. Summarize how the Fund intends to achieve its investment objectives by identifying the Fund's principal investment strategies (including the type or types of securities in which the Fund invests or will invest principally) and any policy to concentrate in securities of issuers in a particular industry or group of industries.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form
-Number N-1A
-Chapter A
-Section 4
-Subsection a

+ Details

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- Definition

This element contains the text of a prospectus supplement (submission type 497) not already contained in an element containing amended text or other data from a previous submission.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form
-Number N-1A

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