Income Taxes - Additional Information (Details) - CAD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Income Tax Examination [Line Items]
Combined Canadian federal and provincial enacted statutory tax rate	26.50%	26.50%	26.50%
Other Accounts Receivable
Income Tax Examination [Line Items]
Current income taxes receivable	$ 5,259
Accounts Payable
Income Tax Examination [Line Items]
Current income taxes payable	$ 5,267	$ 14,690