v3.26.1
Property, Plant and Equipment - Carrying Values of Property, Plant and Equipment (Details) - CAD ($)
$ in Thousands
Mar. 31, 2026
Mar. 31, 2025
Mar. 31, 2024
Disclosure of detailed information about property, plant and equipment [line items]      
Property, plant and equipment $ 123,688 $ 268,107 $ 294,324
Cost      
Disclosure of detailed information about property, plant and equipment [line items]      
Property, plant and equipment 292,447 559,773  
Accumulated depreciation      
Disclosure of detailed information about property, plant and equipment [line items]      
Property, plant and equipment (168,759) (291,666)  
Owned assets      
Disclosure of detailed information about property, plant and equipment [line items]      
Property, plant and equipment 110,294 240,814 263,590
Owned assets | Cost      
Disclosure of detailed information about property, plant and equipment [line items]      
Property, plant and equipment 250,471 506,012  
Owned assets | Accumulated depreciation      
Disclosure of detailed information about property, plant and equipment [line items]      
Property, plant and equipment (140,177) (265,198)  
Owned assets | Land      
Disclosure of detailed information about property, plant and equipment [line items]      
Property, plant and equipment 12,052 43,937 43,914
Owned assets | Land | Cost      
Disclosure of detailed information about property, plant and equipment [line items]      
Property, plant and equipment 12,052 43,937  
Owned assets | Land | Accumulated depreciation      
Disclosure of detailed information about property, plant and equipment [line items]      
Property, plant and equipment 0 0  
Owned assets | Buildings      
Disclosure of detailed information about property, plant and equipment [line items]      
Property, plant and equipment 61,240 131,343 143,867
Owned assets | Buildings | Cost      
Disclosure of detailed information about property, plant and equipment [line items]      
Property, plant and equipment 110,125 242,939  
Owned assets | Buildings | Accumulated depreciation      
Disclosure of detailed information about property, plant and equipment [line items]      
Property, plant and equipment (48,885) (111,596)  
Owned assets | Construction in progress      
Disclosure of detailed information about property, plant and equipment [line items]      
Property, plant and equipment 16,950 27,153 25,685
Owned assets | Construction in progress | Cost      
Disclosure of detailed information about property, plant and equipment [line items]      
Property, plant and equipment 17,464 27,153  
Owned assets | Construction in progress | Accumulated depreciation      
Disclosure of detailed information about property, plant and equipment [line items]      
Property, plant and equipment (514) 0  
Owned assets | Computer software & equipment      
Disclosure of detailed information about property, plant and equipment [line items]      
Property, plant and equipment 1,000 1,196 1,198
Owned assets | Computer software & equipment | Cost      
Disclosure of detailed information about property, plant and equipment [line items]      
Property, plant and equipment 21,351 31,963  
Owned assets | Computer software & equipment | Accumulated depreciation      
Disclosure of detailed information about property, plant and equipment [line items]      
Property, plant and equipment (20,351) (30,767)  
Owned assets | Furniture & fixtures      
Disclosure of detailed information about property, plant and equipment [line items]      
Property, plant and equipment 1,269 995 1,456
Owned assets | Furniture & fixtures | Cost      
Disclosure of detailed information about property, plant and equipment [line items]      
Property, plant and equipment 7,024 7,614  
Owned assets | Furniture & fixtures | Accumulated depreciation      
Disclosure of detailed information about property, plant and equipment [line items]      
Property, plant and equipment (5,755) (6,619)  
Owned assets | Production & other equipment      
Disclosure of detailed information about property, plant and equipment [line items]      
Property, plant and equipment 17,783 36,190 47,470
Owned assets | Production & other equipment | Cost      
Disclosure of detailed information about property, plant and equipment [line items]      
Property, plant and equipment 82,455 152,406  
Owned assets | Production & other equipment | Accumulated depreciation      
Disclosure of detailed information about property, plant and equipment [line items]      
Property, plant and equipment (64,672) (116,216)  
Right-of-use leased assets      
Disclosure of detailed information about property, plant and equipment [line items]      
Property, plant and equipment 13,394 27,293 30,734
Right-of-use leased assets | Cost      
Disclosure of detailed information about property, plant and equipment [line items]      
Property, plant and equipment 41,976 53,761  
Right-of-use leased assets | Accumulated depreciation      
Disclosure of detailed information about property, plant and equipment [line items]      
Property, plant and equipment (28,582) (26,468)  
Right-of-use leased assets | Land      
Disclosure of detailed information about property, plant and equipment [line items]      
Property, plant and equipment 0 11,629 12,289
Right-of-use leased assets | Land | Cost      
Disclosure of detailed information about property, plant and equipment [line items]      
Property, plant and equipment 1,990 13,494  
Right-of-use leased assets | Land | Accumulated depreciation      
Disclosure of detailed information about property, plant and equipment [line items]      
Property, plant and equipment (1,990) (1,865)  
Right-of-use leased assets | Buildings      
Disclosure of detailed information about property, plant and equipment [line items]      
Property, plant and equipment 13,192 15,388 18,100
Right-of-use leased assets | Buildings | Cost      
Disclosure of detailed information about property, plant and equipment [line items]      
Property, plant and equipment 35,487 34,801  
Right-of-use leased assets | Buildings | Accumulated depreciation      
Disclosure of detailed information about property, plant and equipment [line items]      
Property, plant and equipment (22,295) (19,413)  
Right-of-use leased assets | Production & other equipment      
Disclosure of detailed information about property, plant and equipment [line items]      
Property, plant and equipment 202 276 $ 345
Right-of-use leased assets | Production & other equipment | Cost      
Disclosure of detailed information about property, plant and equipment [line items]      
Property, plant and equipment 4,499 5,466  
Right-of-use leased assets | Production & other equipment | Accumulated depreciation      
Disclosure of detailed information about property, plant and equipment [line items]      
Property, plant and equipment $ (4,297) $ (5,190)