S000010032 [Member] Performance Management - The National Tax-Free Intermediate Bond Fund |
Oct. 31, 2025 |
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| Prospectus [Line Items] | |
| Bar Chart and Performance Table [Heading] | Fund Performance |
| Performance Narrative [Text Block] | The bar chart and table below provide an indication of the risks of investing in the Fund by showing: (a) changes in the performance of the Fund’s shares from year to year; and (b) how the average annual total returns of the Fund’s shares compare to those of a broad-based securities market index and an additional index with characteristics relevant to the Fund. The Fund’s past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future. To obtain updated performance information, please visit the Fund’s website at www.commercefunds.com or by calling 1‑800‑995‑6365.
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| Performance Past Does Not Indicate Future [Text] | The Fund’s past performance, before and after taxes, is not necessarily an indication of how the Fund will perform in the future. |
| Performance Information Illustrates Variability of Returns [Text] | The bar chart and table below provide an indication of the risks of investing in the Fund by showing: (a) changes in the performance of the Fund’s shares from year to year; and (b) how the average annual total returns of the Fund’s shares compare to those of a broad-based securities market index and an additional index with characteristics relevant to the Fund. |
| Performance Additional Market Index [Text] | The Bloomberg 3‑15 Year Blend Municipal Bond Index is an unmanaged index comprised of investment-grade municipal securities ranging from 2 to 17 years in maturity. |
| Bar Chart [Heading] | Year‑by‑Year Total Returns as of 12/31 Each YearTOTAL RETURNCALENDAR YEAR |
| Bar Chart Closing [Text Block] | Best Quarter* Q4 ‘23 7.21% Worst Quarter* Q1 ‘22 –5.43% * Please note that “Best Quarter” and “Worst Quarter” figures are applicable only to the time period covered by the bar chart. |
| Performance Table Heading | Average Annual Total Returns For the periods endedDecember 31, 2025 |
| Performance Table Narrative | After‑tax returns below are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. Actual after‑tax returns depend on an investor’s tax situation and may differ from those shown. After‑tax returns shown are not relevant to investors who hold Fund shares through tax‑advantaged arrangements such as a 401(k) plan or individual retirement account (IRA).
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| Performance Table Uses Highest Federal Rate | After‑tax returns below are calculated using the historical highest individual federal marginal income tax rates and do not reflect the impact of state and local taxes. |
| Performance Table Not Relevant to Tax Deferred | Actual after‑tax returns depend on an investor’s tax situation and may differ from those shown. After‑tax returns shown are not relevant to investors who hold Fund shares through tax‑advantaged arrangements such as a 401(k) plan or individual retirement account (IRA). |
| Index No Deduction for Fees, Expenses, or Taxes [Text] | The Index figures do not reflect any deduction for fees, taxes or expenses. |
| Performance Availability Website Address [Text] | www.commercefunds.com |
| Performance Availability Phone [Text] | 1‑800‑995‑6365 |
| Shares | |
| Prospectus [Line Items] | |
| Highest Quarterly Return, Label [Optional Text] | Best Quarter |
| Highest Quarterly Return | 7.21% |
| Highest Quarterly Return, Date | Dec. 31, 2023 |
| Lowest Quarterly Return, Label [Optional Text] | Worst Quarter |
| Lowest Quarterly Return | (5.43%) |
| Lowest Quarterly Return, Date | Mar. 31, 2022 |