Share Capital - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Thousands			1 Months Ended	3 Months Ended	9 Months Ended
	Jul. 10, 2023	Feb. 25, 2022	Jun. 30, 2018	Sep. 30, 2023	Sep. 30, 2023	Sep. 05, 2023	Dec. 31, 2022	Sep. 30, 2022
Business combination, contigent liability				$ 0	$ 0			$ 200
Current liabilities				149,882	149,882		$ 146,571
Issuance of deferred shares				12,973	12,973		36,211
Dharma Pharmaceuticals LLC [Member]
Business combination, contigent liability				32,789	32,789		41,943
Current liabilities							$ 11,400
Restricted Stock Units (RSUs) [Member]
Cost Not yet Recognized, Amount				$ 45,048	$ 45,048
Cost Not yet Recognized, Period for Recognition					2 years 18 days
Multiple Voting Shares [Member]
Conversion Of Stock, Shares Converted				25,000
Common Stock, Shares, Outstanding				38,531	38,531		38,531
Multiple Voting Shares [Member] | Conversion Of Multiple Voting Shares [member]
Conversion Of Stock, Shares Converted					25,000
Conversion of Stock, Shares Issued				25,000
Voting Rights					100
Subordinate Voting Shares [Member]
Common Stock, Shares, Outstanding				210,042,431	210,042,431		206,991,275
Issuance of shares under business combinations and investments, value		$ 12,524
Subordinate Voting Shares [Member] | Dharma Pharmaceuticals LLC [Member]
Issuance of shares under business combinations and investments	792,424	822,447
Subordinate Voting Shares [Member] | Dharma Pharmaceuticals LLC [Member] | Maximum [Member]
Contingent consideration					$ 65,000
Subordinate Voting Shares [Member] | GTII Stock and Incentive Plan [Member]
Percentage of maximum number of shares issued under the plan			10.00%
Subordinate Voting Shares [Member] | Conversion Of Multiple Voting Shares [member]
Conversion Of Stock, Shares Converted					0
Conversion of Stock, Shares Issued				2,500,000	2,500,000
Shares Available For Conversion				3,853,100	3,853,100
Super Voting Shares [Member]
Conversion Of Stock, Shares Converted				25,000
Common Stock, Shares, Outstanding				226,690	226,690		251,690
Super Voting Shares [Member] | Conversion Of Super Voting Shares [member]
Conversion Of Stock, Shares Converted				25,000
Voting Rights					1,000
Shares Available For Conversion				22,669,000	22,669,000
Repurchase of Subordinate Voting Shares
Percentage of Stock Repurchase Program, Authorized						5.00%
Company Authorized Spend For Repurchase Program						$ 50,000
Company Repurchased Subordinate Voting Shares				2,500,000	2,500,000	10,486,951
Repurchased Average Price Per share					$ 9.96