Fees and Expenses - Multi-Sector Income Fund	Aug. 25, 2026 USD ($)
Prospectus [Line Items]
Expense Heading [Optional Text]	Fees and Expenses of the Fund
Expense Narrative [Text Block]	This table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $100,000 in Class A Shares of Principal Funds, Inc. More information about these and other discounts is available from your financial intermediary and in “Choosing a Share Class and The Costs of Investing” beginning on page 35 of the Fund’s Prospectus, Appendix B to the Prospectus titled “Intermediary-Specific Sales Charge Waivers and Reductions,” and “Multiple Class Structure” beginning on page 72 of the Fund’s Statement of Additional Information. If you purchase Institutional Class or Class R-6 shares through certain programs offered by certain financial intermediaries, you may be required to pay a commission and/or other forms of compensation to the broker, or to your Financial Professional or other financial intermediary.
Expense Breakpoint Discounts [Text]	You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $100,000 in Class A Shares of Principal Funds, Inc.
Expenses Restated to Reflect Current [Text]	Fees have been restated to reflect current fees.
Expense Breakpoint, Minimum Investment Required [Amount]	$ 100,000
Shareholder Fees Caption [Optional Text]	Shareholder Fees (fees paid directly from your investment)
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]	This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds.
Expense Example by, Year, Caption [Text]	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 assumes conversion of the Class C shares to Class A shares after the eighth year. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same. The calculation of costs takes into account any applicable contractual fee waivers and/or expense reimbursements for the period noted in the table above. Although your actual costs may be higher or lower, based on these assumptions your costs would be:
Expense Example, No Redemption, By Year, Caption [Text]	With respect to Class C shares, you would pay the following expenses if you did not redeem your shares (all other classes would be the same as in the above example):
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 Fund 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 92.9% of the average value of its portfolio.
Portfolio Turnover, Rate	92.90%

Fees and Expenses - Multi-Sector Income Fund

Aug. 25, 2026

USD ($)

Fees and Expenses of the Fund

This table describes the fees and expenses that you may pay if you buy, hold, and sell shares of the Fund. You may pay other fees, such as brokerage commissions and other fees to financial intermediaries, which are not reflected in the tables and examples below. You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $100,000 in Class A Shares of Principal Funds, Inc. More information about these and other discounts is available from your financial intermediary and in “Choosing a Share Class and The Costs of Investing” beginning on page 35 of the Fund’s Prospectus, Appendix B to the Prospectus titled “Intermediary-Specific Sales Charge Waivers and Reductions,” and “Multiple Class Structure” beginning on page 72 of the Fund’s Statement of Additional Information.

If you purchase Institutional Class or Class R-6 shares through certain programs offered by certain financial intermediaries, you may be required to pay a commission and/or other forms of compensation to the broker, or to your Financial Professional or other financial intermediary.

Expense Breakpoint Discounts [Text]

You may qualify for sales charge discounts if you and your family invest, or agree to invest in the future, at least $100,000 in Class A Shares of Principal Funds, Inc.

Expenses Restated to Reflect Current [Text]

Fees have been restated to reflect current fees.

Expense Breakpoint, Minimum Investment Required [Amount]

$ 100,000

Shareholder Fees Caption [Optional Text]

Shareholder Fees (fees paid directly from your investment)

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]

This Example is intended to help you compare the cost of investing in the Fund with the cost of investing in other mutual funds.

Expense Example by, Year, Caption [Text]

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 assumes conversion of the Class C shares to Class A shares after the eighth year. The Example also assumes that your investment has a 5% return each year and that the Fund’s operating expenses remain the same. The calculation of costs takes into account any applicable contractual fee waivers and/or expense reimbursements for the period noted in the table above. Although your actual costs may be higher or lower, based on these assumptions your costs would be:

Expense Example, No Redemption, By Year, Caption [Text]

With respect to Class C shares, you would pay the following expenses if you did not redeem your shares (all other classes would be the same as in the above example):

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 Fund 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 92.9% of the average value of its portfolio.

Portfolio Turnover, Rate

92.90%