XML 18 R2.htm IDEA: XBRL DOCUMENT v3.24.4
Shareholder Report
 12 Months Ended
Nov. 30, 2024
USD ($)
Holding
Shareholder Report [Line Items]  
Document Type N-CSR
Amendment Flag false
Registrant Name General Money Market Fund, Inc.
Entity Central Index Key 0000353560
Entity Investment Company Type N-1A
Document Period End Date Nov. 30, 2024
C000000265 [Member]  
Shareholder Report [Line Items]  
Fund Name Dreyfus Money Market Fund
Class Name Wealth Shares
Trading Symbol GMMXX
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about Dreyfus Money Market Fund (the “Fund”) for the period of December 1, 2023 to November 30, 2024.
Shareholder Report Annual or Semi-Annual annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at www.dreyfus.com/products/mm.html#overview. You can also request this information by calling 1-800-373-9387 (inside the U.S. only) or by sending an e-mail request to info@bny.com.
Additional Information Phone Number 1-800-373-9387
Additional Information Email info@bny.com
Additional Information Website www.dreyfus.com/products/mm.html#overview
Expenses [Text Block]
What were the Fund’s costs for the last year ?
(based on a hypothetical $10,000 investment)
Share Class Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment
Wealth Shares $55 0.54%
Expenses Paid, Amount $ 55
Expense Ratio, Percent 0.54%
Net Assets $ 2,154,000,000
Holdings Count | Holding 93
Advisory Fees Paid, Amount $ 4,183,576
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (AS OF 11/30/24 )

Fund Size (Millions)
Number of Holdings		 Total Advisory Fee Paid During
Period
$2,154 93 $4,183,576
Holdings [Text Block]
Portfolio Holdings (as of 11/30/24 )
Allocation of Holdings (Based on Net Assets)
Graphical Representation - Top N Holdings Chart
C000000266 [Member]  
Shareholder Report [Line Items]  
Fund Name Dreyfus Money Market Fund
Class Name Service Shares
Trading Symbol GMBXX
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about Dreyfus Money Market Fund (the “Fund”) for the period of December 1, 2023 to November 30, 2024.
Shareholder Report Annual or Semi-Annual annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at www.dreyfus.com/products/mm.html#overview. You can also request this information by calling 1-800-373-9387 (inside the U.S. only) or by sending an e-mail request to info@bny.com.
Additional Information Phone Number 1-800-373-9387
Additional Information Email info@bny.com
Additional Information Website www.dreyfus.com/products/mm.html#overview
Expenses [Text Block]
What were the Fund’s costs for the last year ?
(based on a hypothetical $10,000 investment)
Share Class Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment
Service Shares* $102 1.00%
*
During the period, fees were waived and/or expenses reimbursed pursuant to an agreement with the Fund’s investment adviser, BNY Mellon Investment Adviser, Inc. If this agreement is not extended in the future, expenses could be higher.
Expenses Paid, Amount $ 102 [1]
Expense Ratio, Percent 1.00% [1]
Net Assets $ 2,154,000,000
Holdings Count | Holding 93
Advisory Fees Paid, Amount $ 4,183,576
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (AS OF 11/30/24 )

Fund Size (Millions)
Number of Holdings		 Total Advisory Fee Paid During
Period
$2,154 93 $4,183,576
Holdings [Text Block]
Portfolio Holdings (as of 11/30/24 )
Allocation of Holdings (Based on Net Assets)
Graphical Representation - Top N Holdings Chart
C000157127 [Member]  
Shareholder Report [Line Items]  
Fund Name Dreyfus Money Market Fund
Class Name Premier Shares
Trading Symbol GMGXX
Annual or Semi-Annual Statement [Text Block] This annual shareholder report contains important information about Dreyfus Money Market Fund (the “Fund”) for the period of December 1, 2023 to November 30, 2024.
Shareholder Report Annual or Semi-Annual annual shareholder report
Additional Information [Text Block] You can find additional information about the Fund at www.dreyfus.com/products/mm.html#overview. You can also request this information by calling 1-800-373-9387 (inside the U.S. only) or by sending an e-mail request to info@bny.com.
Additional Information Phone Number 1-800-373-9387
Additional Information Email info@bny.com
Additional Information Website www.dreyfus.com/products/mm.html#overview
Expenses [Text Block]
What were the Fund’s costs for the last year ?
(based on a hypothetical $10,000 investment)
Share Class Costs of a $10,000 investment Costs paid as a percentage of a $10,000 investment
Premier Shares $29 0.28%
Expenses Paid, Amount $ 29
Expense Ratio, Percent 0.28%
Net Assets $ 2,154,000,000
Holdings Count | Holding 93
Advisory Fees Paid, Amount $ 4,183,576
Additional Fund Statistics [Text Block]
KEY FUND STATISTICS (AS OF 11/30/24 )

Fund Size (Millions)
Number of Holdings		 Total Advisory Fee Paid During
Period
$2,154 93 $4,183,576
Holdings [Text Block]
Portfolio Holdings (as of 11/30/24 )
Allocation of Holdings (Based on Net Assets)
Graphical Representation - Top N Holdings Chart
[1] During the period, fees were waived and/or expenses reimbursed pursuant to an agreement with the Fund’s investment adviser, BNY Mellon Investment Adviser, Inc. If this agreement is not extended in the future, expenses could be higher.