CONDENSED CONSOLIDATED INTERIM STATEMENTS OF CHANGES IN SHAREHOLDERS' DEFICIT (unaudited) - USD ($) $ in Thousands	Total	Total 4Front Ventures Corp. Shareholders' Equity	Common Stock	Additional Paid-In Capital	Deficit	Non-Controlling Interest
Beginning balance (in shares) at Dec. 31, 2022			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
Beginning balance at Dec. 31, 2022	28,351	28,258	$ 304,602	59,411	(335,755)	93
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(84,952)
Ending balance (in shares) at Sep. 30, 2023			659,159,977
Ending balance at Sep. 30, 2023	(50,592)	(50,700)	$ 306,561	63,461	(420,722)	108
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]
Share-based compensation	214	214		214
Shares issued for asset acquisition (in shares)			2,380,952
Shares issued for asset acquisition	447	447	$ 447
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
Ending balance at Jun. 30, 2023	7,826	7,723	$ 305,699	60,645	(358,621)	103
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation	2,634	2,634		2,634
Warrants issued	182	182		182
Shares issued for executive compensation (in shares)			9,300,250
Shares issued for executive compensation	862	862	$ 862
Net loss	(62,096)	(62,101)			(62,101)	5
Ending balance (in shares) at Sep. 30, 2023			659,159,977
Ending balance at Sep. 30, 2023	$ (50,592)	(50,700)	$ 306,561	63,461	(420,722)	108
Beginning balance (in shares) at Dec. 31, 2023	669,519,349		669,519,349
Beginning balance at Dec. 31, 2023	$ (51,394)	(51,502)	$ 308,952	66,948	(427,402)	108
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Conversion of debt to equity (in shares)			244,680,852
Conversion of debt to equity	28,270	28,270	$ 28,270
Share-based compensation	1,008	1,008		1,008
Net loss	(18,453)	(18,453)			(18,453)
Ending balance (in shares) at Mar. 31, 2024			914,200,201
Ending balance at Mar. 31, 2024	$ (40,569)	(40,677)	$ 337,222	67,956	(445,855)	108
Beginning balance (in shares) at Dec. 31, 2023	669,519,349		669,519,349
Beginning balance at Dec. 31, 2023	$ (51,394)	(51,502)	$ 308,952	66,948	(427,402)	108
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Shares issued to settle payables (in shares)	245,680,852
Net loss	$ (29,723)
Ending balance (in shares) at Sep. 30, 2024	915,200,201		915,200,201
Ending balance at Sep. 30, 2024	$ (48,453)	(48,561)	$ 337,222	71,342	(457,125)	108
Beginning balance (in shares) at Mar. 31, 2024			914,200,201
Beginning balance at Mar. 31, 2024	(40,569)	(40,677)	$ 337,222	67,956	(445,855)	108
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation	786	786		786
Shares issued for executive compensation (in shares)			1,000,000
Shares issued for executive compensation	112	112		112
Net loss	(4,867)	(4,867)			(4,867)
Ending balance (in shares) at Jun. 30, 2024			915,200,201
Ending balance at Jun. 30, 2024	(44,538)	(44,646)	$ 337,222	68,854	(450,722)	108
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Share-based compensation	688	688		688
Warrants issued	267	267		267
Equity component of debt	1,533	1,533		1,533
Net loss	$ (6,403)	(6,403)			(6,403)
Ending balance (in shares) at Sep. 30, 2024	915,200,201		915,200,201
Ending balance at Sep. 30, 2024	$ (48,453)	$ (48,561)	$ 337,222	$ 71,342	$ (457,125)	$ 108