Janus Henderson Forty Portfolio Annual Fund Operating Expenses - Institutional Shares [Member] - Janus Henderson Forty Portfolio - Institutional Shares	Dec. 31, 2025
Prospectus [Line Items]
Management Fees (as a percentage of Assets)	0.54%	[1]
Other Expenses (as a percentage of Assets):	0.08%
Expenses (as a percentage of Assets)	0.62%

[1] This fee may adjust up or down monthly based on the Portfolio’s performance relative to its benchmark index over the performance measurement period. For more information regarding performance-based advisory fees, refer to “Management Expenses” in the Portfolio’s Prospectus.