Note 18 - Income taxes - Income Tax (Recovery) Expense (Details) - USD ($) $ in Thousands	12 Months Ended
Mar. 31, 2022	Mar. 31, 2021
Income tax (recovery) expense [Abstract]
Current tax (recovery) expense	$ 0	$ 0
Deferred tax (recovery) expense	(648)	0
Income tax (recovery) expense	$ (648)	$ 0

Amount of deferred income tax expense (benefit) pertaining to income (loss) from continuing operations.

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Name:	us-gaap_DeferredIncomeTaxExpenseBenefit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration