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

Quarterly report [Sections 13 or 15(d)]

Contingencies and Guarantees - Additional Information (Detail)

Contingencies and Guarantees - Additional Information (Detail) - USD ($)											3 Months Ended	36 Months Ended
	Jan. 05, 2026	Sep. 19, 2025	Aug. 20, 2025	Aug. 08, 2025	Jun. 15, 2025	Jun. 04, 2025	Apr. 05, 2023	Aug. 19, 2021	Aug. 23, 2019	Apr. 24, 2019	Mar. 31, 2026	Jan. 05, 2026	Jan. 05, 2029	Dec. 31, 2025
Contingencies And Guarantees [Line Items]
Claim for alleged payments										$ 1,300,000
Disputed Debentures and Related Indenture, Amount										111,000,000
Damages For Breach of The Duty Of Good Faith						$ 1,000,000
Breach Of Security Subordination Agreement, Amount										$ 3,500,000
Damages For Breach of Consultancy Agreement						400,000
Common stock, shares, issued											6,972,552,000			6,859,128,000
Breach of the Disputed Debentures and Indentures and Breach of Fiduciary Obligations						1,800,000
Alleged Fee							$ 2,200,000
Damages For Breach of Consultancy Agreement Plus Certain Warrants						$ 200,000
Loss Contingency Plaintiffs Value					$ 5,500,000
Loss contingency, settlement agreement, court					(i) $1,250,000 within five (5) business days of executing the Roberts Settlement Agreement; (ii)
William Huber [Member]
Contingencies And Guarantees [Line Items]
Damages For Breach of The Duty Of Good Faith									$ 1,000,000
Breach Of Security Subordination Agreement, Amount									3.5
Damages For Breach of Consultancy Agreement									400,000
Breach of the Disputed Debentures and Indentures and Breach of Fiduciary Obligations									111
Damages For Breach of Consultancy Agreement Plus Certain Warrants									$ 200,000
Maximum [Member]
Contingencies And Guarantees [Line Items]
Total Damages Sought Value								$ 10,000,000
Loss Contingency, Damages Sought, Value								10,000,000
Minimum [Member]
Contingencies And Guarantees [Line Items]
Total Damages Sought Value								1,000,000
Loss Contingency, Damages Sought, Value								$ 1,000,000
Settlement Agreement [Member]
Contingencies And Guarantees [Line Items]
Payments mistakenly		$ 1,700,000	$ 300,000	$ 2,000,000
Claim by prior shareholders of Grow Healthy Holdings LLC [Member]
Contingencies And Guarantees [Line Items]
Loss Contingency Accrual											$ 22,000,000
Counterclaim Against Canaccord [Member]
Contingencies And Guarantees [Line Items]
Payments mistakenly											$ 300,000
Roberts Settlement Agreement [Member]
Contingencies And Guarantees [Line Items]
Debt Instrument, Interest Rate, Stated Percentage													6.00%
Loss Contingency Plaintiffs Value	$ 150,000				$ 1,250,000							$ 4,100,000