iAnthus Capital Holdings, Inc. Quarterly report [Sections 13 or 15(d)]

Financial Instruments - Summary of Changes in Level One and Level Three Financial Assets (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Gain on equity method investments	$ 38	$ (17)
4 Front Venture Corp [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Beginning balance	2
Additions	0
Revaluations	(2)
Gain on equity method investments	0
Ending balance	0
Other Long-term Investments [Member] \| The Pharm Stand, LLC
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Beginning balance	125
Additions	0
Revaluations	0
Gain on equity method investments	0
Ending balance	125
Other Long-term Investments [Member] \| Island Thyme LLC [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Beginning balance	715
Additions	0
Revaluations	0
Gain on equity method investments	38
Ending balance	$ 753

Amount of income (loss) for proportionate share of equity method investee's income (loss).