| Shareholder Report | 6 Months Ended |
| Sep. 30, 2024 USD ($) Holding |
| Shareholder Report [Line Items] | | |
| Document Type | N-CSRS | |
| Amendment Flag | false | |
| Registrant Name | Dreyfus Institutional Preferred Money Market Funds | |
| Entity Central Index Key | 0001038520 | |
| Entity Investment Company Type | N-1A | |
| Document Period End Date | Sep. 30, 2024 | |
| Dreyfus Institutional Preferred Government Plus Money Market Fund - Institutional Shares | | |
| Shareholder Report [Line Items] | | |
| Fund Name | Dreyfus Institutional Preferred Government Plus Money Market Fund | |
| Class Name | Institutional Shares | |
| No Trading Symbol Flag | true | |
| Annual or Semi-Annual Statement [Text Block] | This semi-annual shareholder report contains important information about Dreyfus Institutional Preferred Government Plus Money Market Fund (the “Fund”) for the period of April 1, 2024 to September 30, 2024. | |
| Shareholder Report Annual or Semi-Annual | semi-annual shareholder report | |
| Additional Information [Text Block] | You can find additional information about the Fund at www.dreyfus.com/products/mm.html#overview | |
| 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 six months? (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 Institutional Shares * $ 0.00 % ** * During the period, fees were waived and/or expenses reimbused 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. ** Annualized. | |
| Expenses Paid, Amount | $ 0 | [1] |
| Expense Ratio, Percent | 0% | [1],[2] |
| Net Assets | $ 966,000,000 | |
| Holdings Count | Holding | 8 | |
| Additional Fund Statistics [Text Block] | KEY FUND STATISTICS (AS OF 9/30/ 24 $ 966 8 | |
| Holdings [Text Block] | Portfolio Holdings (as of 9/30/24) Allocation of Holdings (Based on Net Assets) | |
|
| [1]During the period, fees were waived and/or expenses reimbused 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.[2]Annualized. |
