Fair Value of Financial Instruments - Summary of Financial Assets and Liabilities Measured at Estimated Fair Value on a Recurring Basis (Details) - Fair Value Measurements Recurring - CAD ($) $ in Thousands	Jun. 30, 2026	Mar. 31, 2026
Assets:
Restricted short-term investments	$ 5,058	$ 5,046
Other investments	123,568	106,025
Liabilities:
Warrant derivative liability	26,863	27,522
Level 1
Assets:
Restricted short-term investments	5,058	5,046
Other investments	47	46
Level 3
Assets:
Other investments	123,521	105,979
Liabilities:
Warrant derivative liability	$ 26,863	$ 27,522

Fair Value of Financial Instruments - Summary of Financial Assets and Liabilities Measured at Estimated Fair Value on a Recurring Basis (Details) - Fair Value Measurements Recurring - CAD ($)
$ in Thousands

Jun. 30, 2026

Mar. 31, 2026

Assets:

Restricted short-term investments

$ 5,058

$ 5,046

Other investments

123,568

106,025

Liabilities:

Warrant derivative liability

26,863