Label	Element	Value
BNY Mellon Active MidCap Fund
Risk/Return:	rr_RiskReturnAbstract
Supplement to Prospectus [Text Block]	rr_SupplementToProspectusTextBlock	May 27, 2020 BNY MELLON ACTIVE MIDCAP FUND Supplement to Current Summary Prospectus and Prospectus The following information supplements the information contained in the fund's summary prospectus and prospectus:
Risk/Return [Heading]	rr_RiskReturnHeading	BNY Mellon Active MidCap Fund
Expense Narrative [Text Block]	rr_ExpenseNarrativeTextBlock	The fund's investment adviser, BNY Mellon Investment Adviser, Inc., has contractually agreed to waive receipt of a portion of its management fee in the amount of .25% of the value of the fund's average daily net assets from June 1, 2020 until November 30, 2020. On or after November 30, 2020, BNY Mellon Investment Adviser, Inc. may terminate this waiver agreement at any time.
Fee Waiver or Reimbursement over Assets, Date of Termination	rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination	Nov. 30, 2020

This table describes the fees and expenses that you may pay if you buy and hold shared of the Fund. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $[_____] in [name of fund family] funds. Include the narrative explanations in the order indicated. A Fund may modify the narrative explanations if the explanation contains comparable information to that shown. The narrative explanation regarding sales charge discounts is only required by a Fund that offers such discounts and should specify the minimum level of investment required to qualify for a discount. Modify the narrative explanation to state that Fund shares are sold on a national securities exchange at the end of the time periods indicated, and that brokerage commissions for buying and selling Fund shares through a broker are not reflected.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form
-Number N-1A
-Chapter A
-Section 3
-Subsection instructions
-Paragraph 1
-Subparagraph b

+ Details

Name:	rr_ExpenseNarrativeTextBlock
Namespace Prefix:	rr_
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Balance Type:	na
Period Type:	duration

- Definition

This element represents the date of expected termination of any expense reimbursement or fee waiver arrangements that reduce any Fund operating expenses (SEC Form N-1A 2006-09-14 A.3.table.1.11 Total Annual Fund Operating Expenses A.3.instructions.3.e).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Form
-Number N-1A
-Chapter A
-Section 3
-Subsection instructions
-Paragraph 3
-Subparagraph e

+ Details

Name:	rr_FeeWaiverOrReimbursementOverAssetsDateOfTermination
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Data Type:	xbrli:stringItemType
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- References

No definition available.

+ Details

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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

Name:	rr_RiskReturnHeading
Namespace Prefix:	rr_
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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

+ Details

Name:	rr_SupplementToProspectusTextBlock
Namespace Prefix:	rr_
Data Type:	nonnum:textBlockItemType
Balance Type:	na
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