v3.26.3
Janus Henderson International Dividend Fund Average Annual Total Returns - Class A C S I N T Shares [Member]
 12 Months Ended 60 Months Ended 120 Months Ended 161 Months Ended
Jun. 30, 2026
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
Dec. 31, 2025
MSCI World ex-USA IndexSM (reflects no deduction for expenses, fees, or taxes, except foreign withholding taxes)[Member]          
Prospectus [Line Items]          
Average Annual Return, Percent   31.85% 9.46% 8.55% 8.16%
Class A | Return Before Taxes[Member]          
Prospectus [Line Items]          
Average Annual Return, Percent [1]   21.51% 9.58% 8.22% 8.27%
Class C | Return Before Taxes[Member]          
Prospectus [Line Items]          
Average Annual Return, Percent [2]   27.09% 10.09% 7.96% 7.88%
Class S | Return Before Taxes[Member]          
Prospectus [Line Items]          
Average Annual Return, Percent   29.00% 11.03% 8.83% 8.67%
Class I | After Taxes on Distributions          
Prospectus [Line Items]          
Average Annual Return, Percent   26.53% 9.87% 8.05% 7.98%
Class I | After Taxes on Distributions and Sales          
Prospectus [Line Items]          
Average Annual Return, Percent   18.39% 8.69% 7.22% 7.22%
Class I | Return Before Taxes[Member]          
Prospectus [Line Items]          
Average Annual Return, Percent   29.25% 11.13% 9.02% 8.93%
Performance Inception Date Aug. 01, 2012        
Class N | Return Before Taxes[Member]          
Prospectus [Line Items]          
Average Annual Return, Percent   29.35% 11.22% 9.07% 8.94%
Class T | Return Before Taxes[Member]          
Prospectus [Line Items]          
Average Annual Return, Percent   29.01% 10.95% 8.82% 8.74%
[1] Calculated assuming maximum permitted sales loads.
[2] The one year return is calculated to include the contingent deferred sales charge.