CONDENSED CONSOLIDATED INTERIM STATEMENTS OF CHANGES IN SHAREHOLDERS' EQUITY (unaudited) - USD ($) $ in Thousands	Total	New England Cannabis Corporation	Island Global Holdings, Inc.	Total 4Front Ventures Corp. Shareholders' Equity	Total 4Front Ventures Corp. Shareholders' Equity New England Cannabis Corporation	Total 4Front Ventures Corp. Shareholders' Equity Island Global Holdings, Inc.	Share Capital	Share Capital New England Cannabis Corporation	Share Capital Island Global Holdings, Inc.	Additional Paid-In Capital	Deficit	Non-Controlling Interest
Beginning balance (in shares) at Dec. 31, 2021							594,181,604
Beginning balance at Dec. 31, 2021	$ 37,532			$ 37,460			$ 274,120			$ 52,197	$ (288,857)	$ 72
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued for pursuant to acquisition (in shares)								28,571,428
Shares issued for pursuant to acquisition		$ 18,200			$ 18,200			$ 18,200
Share-based compensation	1,038			1,038						1,038
Conversion of notes to equity (in shares)							6,235,512
Conversion of notes to equity	3,122			3,122			$ 3,122
Shares issued with exercise of warrants (in shares)							88,659
Shares issued with exercise of warrants	50			50			$ 50
Net loss	(5,894)			(5,899)							(5,899)	5
Ending balance (in shares) at Mar. 31, 2022							629,077,203
Ending balance at Mar. 31, 2022	54,048			53,971			$ 295,492			53,235	(294,756)	77
Beginning balance (in shares) at Dec. 31, 2021							594,181,604
Beginning balance at Dec. 31, 2021	37,532			37,460			$ 274,120			52,197	(288,857)	72
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(12,440)
Ending balance (in shares) at Jun. 30, 2022							637,912,894
Ending balance at Jun. 30, 2022	54,902			54,820			$ 302,502			53,625	(301,307)	82
Beginning balance (in shares) at Mar. 31, 2022							629,077,203
Beginning balance at Mar. 31, 2022	54,048			53,971			$ 295,492			53,235	(294,756)	77
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued for pursuant to acquisition (in shares)									8,783,716
Shares issued for pursuant to acquisition			$ 6,245			$ 6,245			$ 6,245
Share-based compensation	390			390						390
Warrants issued for Island pursuant to acquisition	732			732			$ 732
Shares issued with exercise of stock options (in shares)							51,975
Shares issued with exercise of stock options	33			33			$ 33
Net loss	(6,546)			(6,551)							(6,551)	5
Ending balance (in shares) at Jun. 30, 2022							637,912,894
Ending balance at Jun. 30, 2022	$ 54,902			54,820			$ 302,502			53,625	(301,307)	82
Beginning balance (in shares) at Dec. 31, 2022	643,416,275						643,416,275
Beginning balance at Dec. 31, 2022	$ 28,351			28,258			$ 304,602			59,411	(335,755)	93
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation	1,020			1,020						1,020
Net loss	(11,392)			(11,397)							(11,397)	5
Ending balance (in shares) at Mar. 31, 2023							643,416,275
Ending balance at Mar. 31, 2023	$ 17,979			17,881			$ 304,602			60,431	(347,152)	98
Beginning balance (in shares) at Dec. 31, 2022	643,416,275						643,416,275
Beginning balance at Dec. 31, 2022	$ 28,351			28,258			$ 304,602			59,411	(335,755)	93
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued to settle payables (in shares)	6,443,452
Net loss	$ (22,856)
Ending balance (in shares) at Jun. 30, 2023	649,859,727						649,859,727
Ending balance at Jun. 30, 2023	$ 7,826			7,723			$ 305,699			60,645	(358,621)	103
Beginning balance (in shares) at Mar. 31, 2023							643,416,275
Beginning balance at Mar. 31, 2023	17,979			17,881			$ 304,602			60,431	(347,152)	98
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued for pursuant to acquisition (in shares)							2,380,952
Shares issued for pursuant to acquisition	447			447			$ 447
Share-based compensation	214			214						214
Shares issued to settle payables (in shares)							4,062,500
Shares issued to settle payables	650			650			$ 650
Net loss	$ (11,464)			(11,469)							(11,469)	5
Ending balance (in shares) at Jun. 30, 2023	649,859,727						649,859,727
Ending balance at Jun. 30, 2023	$ 7,826			$ 7,723			$ 305,699			$ 60,645	$ (358,621)	$ 103