Shareholder Fees	Aug. 31, 2024
BNY Mellon AMT-Free Municipal Bond Fund | BNY Mellon AMT-Free Municipal Bond Fund | Class A
Prospectus [Line Items]
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price)	4.50%
Maximum Deferred Sales Charge (as a percentage of Offering Price)	0.00%	[1]
BNY Mellon AMT-Free Municipal Bond Fund | BNY Mellon AMT-Free Municipal Bond Fund | Class C
Prospectus [Line Items]
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price)	0.00%
Maximum Deferred Sales Charge (as a percentage of Offering Price)	1.00%
BNY Mellon AMT-Free Municipal Bond Fund | BNY Mellon AMT-Free Municipal Bond Fund | Class I Shares
Prospectus [Line Items]
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price)	0.00%
Maximum Deferred Sales Charge (as a percentage of Offering Price)	0.00%
BNY Mellon AMT-Free Municipal Bond Fund | BNY Mellon AMT-Free Municipal Bond Fund | Class Y
Prospectus [Line Items]
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price)	0.00%
Maximum Deferred Sales Charge (as a percentage of Offering Price)	0.00%
BNY Mellon AMT-Free Municipal Bond Fund | BNY Mellon AMT-Free Municipal Bond Fund | Class Z
Prospectus [Line Items]
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price)	0.00%
Maximum Deferred Sales Charge (as a percentage of Offering Price)	0.00%
BNY Mellon High Yield Municipal Bond Fund | BNY Mellon High Yield Municipal Bond Fund | Class A
Prospectus [Line Items]
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price)	4.50%
Maximum Deferred Sales Charge (as a percentage of Offering Price)	0.00%	[2]
BNY Mellon High Yield Municipal Bond Fund | BNY Mellon High Yield Municipal Bond Fund | Class C
Prospectus [Line Items]
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price)	0.00%
Maximum Deferred Sales Charge (as a percentage of Offering Price)	1.00%
BNY Mellon High Yield Municipal Bond Fund | BNY Mellon High Yield Municipal Bond Fund | Class I Shares
Prospectus [Line Items]
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price)	0.00%
Maximum Deferred Sales Charge (as a percentage of Offering Price)	0.00%
BNY Mellon High Yield Municipal Bond Fund | BNY Mellon High Yield Municipal Bond Fund | Class Y
Prospectus [Line Items]
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price)	0.00%
Maximum Deferred Sales Charge (as a percentage of Offering Price)	0.00%
BNY Mellon High Yield Municipal Bond Fund | BNY Mellon High Yield Municipal Bond Fund | Class Z
Prospectus [Line Items]
Maximum Sales Charge Imposed on Purchases (as a percentage of Offering Price)	0.00%
Maximum Deferred Sales Charge (as a percentage of Offering Price)	0.00%

[1] Class A shares bought without an initial sales charge as part of an investment of $250,000 or more may be charged a deferred sales charge of 1.00% if redeemed within one year.

[2] Class A shares bought without an initial sales charge as part of an investment of $250,000 or more may be charged a deferred sales charge of 1.00% if redeemed within one year.