iAnthus Capital Holdings, Inc. Annual report [Section 13 and 15(d), not S-K Item 405]

Income Taxes - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2025	Dec. 31, 2024	Dec. 31, 2023
Federal statutory rate	21.00%	21.00%
Uncertain tax position	50.00%
Unrecognized tax benefits	$ 106,900	$ 81,371	$ 0
Domestic Tax Jurisdiction [Member] \| Tax Period Two Thousand And Thirty Five Through Two Thousand And Thirty Seven [Member]
Operating loss carryforwards	152,500
State and Local Jurisdiction [Member] \| Tax Period Two Thousand And Twenty Eight Through Two Thousand And Forty Three [Member]
Operating loss carryforwards		$ 142,100
Canada Revenue Agency [Member] \| Tax Period Two Thousand And Twenty Six Through Two Thousand And Forty Three [Member]
Non-capital loss carryforwards	$ 131,100