Janus Henderson Money Market Fund Performance Management - Class T Shares [Member] - Janus Henderson Money Market Fund |
Jun. 30, 2026 |
|---|---|
| Prospectus [Line Items] | |
| Bar Chart and Performance Table [Heading] | <span style="color:#FFFFFF;font-family:Times New Roman;font-size:10.45pt;font-weight:bold;margin-left:0.0pt;text-transform:uppercase;">Performance information</span> |
| Performance Narrative [Text Block] | The following information provides some indication of the risks of investing in the Fund by showing how the Fund’s performance has varied over time.The bar chart depicts the change in performance from year to year during the periods indicated. The table shows how the Fund’s returns over different periods average out. All figures assume reinvestment of dividends and distributions. For certain periods, the Fund’s performance reflects the effect of expense waivers. Without the effect of these expense waivers, the performance shown would have been lower.The Fund’s past performance does not necessarily indicate how it will perform in the future. Updated performance information is available atjanushenderson.com/performance or by calling 1-877-335-2687. |
| Performance Past Does Not Indicate Future [Text] | <span style="color:#000000;font-family:Times New Roman;font-size:9.50pt;font-style:italic;">The Fund’s past performance does not necessarily indicate how it will perform in the future.</span> |
| Performance Information Illustrates Variability of Returns [Text] | <span style="color:#000000;font-family:Times New Roman;font-size:9.50pt;">The bar chart depicts the change in performance from year to year during the periods indicated. The table shows how the Fund’s returns over different periods average out. All figures assume reinvestment of dividends and distributions.</span> |
| Bar Chart [Heading] | Annual Total Returns for Class T Shares (calendar year-end) |
| Bar Chart Closing [Text Block] | Best Quarter:4th Quarter 20231.23%Worst Quarter:1st Quarter 20160.00%Class T Shares’ year-to-date return as of the calendar quarter endedSeptember 30, 2026was2.47%. |
| Performance Table Heading | <span style="font-family:Times New Roman;font-size:8.55pt;font-weight:bold;margin-left:0.0pt;">Average Annual Total Returns </span><span style="font-family:Times New Roman;font-size:8.55pt;margin-left:0.0pt;">(periods ended 12/31/25)</span> |
| Performance Table Closing [Text Block] | Updated performance information is available atjanushenderson.com/performance or by calling 1-877-335-2687. |
| Money Market Seven Day Yield, Caption [Optional Text] | <span style="font-family:Times New Roman;font-size:9.50pt;">The 7-day yield on December 31, 2025 was </span><span style="font-family:Times New Roman;font-size:9.50pt;">3.42</span><span style="font-family:Times New Roman;font-size:9.50pt;">% for Janus Henderson Money Market Fund.</span> |
| Money Market Seven Day Yield | 3.42% |
| Performance Availability Website Address [Text] | <span style="color:#000000;font-family:Times New Roman;font-size:9.50pt;font-style:italic;">janushenderson.com/performance</span> |
| Performance Availability Phone [Text] | <span style="color:#000000;font-family:Times New Roman;font-size:9.50pt;font-style:italic;">1-877-335-2687</span> |
| Class T | |
| Prospectus [Line Items] | |
| Year to Date Return, Label [Optional Text] | <span style="font-family:Times New Roman;font-size:9.50pt;margin-left:0.0pt;">Class T Shares’ year-to-date return as of the calendar quarter ended</span> |
| Bar Chart, Year to Date Return | 2.47% |
| Bar Chart, Year to Date Return, Date | Sep. 30, 2026 |
| Highest Quarterly Return, Label [Optional Text] | <span style="font-family:Times New Roman;font-size:8.55pt;font-weight:bold;margin-left:0.0pt;">Best Quarter:</span> |
| Highest Quarterly Return | 1.23% |
| Highest Quarterly Return, Date | Dec. 31, 2023 |
| Lowest Quarterly Return, Label [Optional Text] | <span style="font-family:Times New Roman;font-size:8.55pt;font-weight:bold;margin-left:0.0pt;">Worst Quarter:</span> |
| Lowest Quarterly Return | none |
| Lowest Quarterly Return, Date | Mar. 31, 2016 |