Leases - Summary of Lease Right-of-use Assets and Liabilities (Details) - CAD ($) $ in Thousands	Mar. 31, 2024	Mar. 31, 2023
Lessee Disclosure [Abstract]
Operating lease	$ 7,154	$ 17,850
Operating Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Property, plant and equipment	Property, plant and equipment
Finance lease	$ 5,362	$ 8,838
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible Enumeration]	Property, plant and equipment	Property, plant and equipment
Operating and finance lease right of use asset	$ 12,516	$ 26,688
Operating lease	$ 11,733	$ 8,880
Operating Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Other liabilities	Other liabilities
Finance lease	$ 3,440	$ 19,541
Finance Lease, Liability, Current, Statement of Financial Position [Extensible Enumeration]	Other liabilities	Other liabilities
Operating lease	$ 23,084	$ 38,719
Operating Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Other liabilities	Other liabilities
Finance lease	$ 32,513	$ 39,648
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible Enumeration]	Other liabilities	Other liabilities
Total finance lease liability, noncurrent	$ 70,770	$ 106,788