Fees and Expenses - U.S. Monthly Income Fund for Puerto Rico Residents, Inc.	Dec. 31, 2025
Prospectus [Line Items]
Expense Heading [Optional Text]	Fees and Expenses of the Fund
Expense Narrative [Text Block]	The following table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund (“Shares”). You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and example below. Information about sales charge and other discounts is available from your financial intermediary and in “Managing Your Fund Account” on page 21 of this prospectus.
Shareholder Fees Caption [Optional Text]	Shareholder Fees (fees paid directly from your investment in the Fund)
Operating Expenses Caption [Optional Text]	Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)
Expense Example [Heading]	Example
Expense Example Narrative [Text Block]	The following example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your Shares at the end of those periods. The example also assumes that your investment has a 5% return each year and that the Fund’s total annual operating expenses remains the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Portfolio Turnover [Heading]	Portfolio Turnover
Portfolio Turnover [Text Block]	The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the Example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 3.44% of the average value of its portfolio.
Portfolio Turnover, Rate	3.44%

Fees and Expenses - U.S. Monthly Income Fund for Puerto Rico Residents, Inc.

Dec. 31, 2025

Fees and Expenses of the Fund

The following table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund (“Shares”). You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and example below. Information about sales charge and other discounts is available from your financial intermediary and in “Managing Your Fund Account” on page 21 of this prospectus.

Shareholder Fees Caption [Optional Text]

Shareholder Fees (fees paid directly from your investment in the Fund)

Operating Expenses Caption [Optional Text]

Annual Fund Operating Expenses (expenses that you pay each year as a percentage of the value of your investment)

Expense Example [Heading]

Example

Expense Example Narrative [Text Block]

The following example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds. The example assumes that you invest $10,000 in the Fund for the time periods indicated and then redeem all of your Shares at the end of those periods. The example also assumes that your investment has a 5% return each year and that the Fund’s total annual operating expenses remains the same. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Portfolio Turnover [Heading]

Portfolio Turnover

Portfolio Turnover [Text Block]

The Fund pays transaction costs, such as commissions, when it buys and sells securities (or “turns over” its portfolio). A higher portfolio turnover rate may indicate higher transaction costs and may result in higher taxes when Shares are held in a taxable account. These costs, which are not reflected in annual fund operating expenses or in the Example, affect the Fund’s performance. During the most recent fiscal year, the Fund’s portfolio turnover rate was 3.44% of the average value of its portfolio.

Portfolio Turnover, Rate

3.44%