Note 10 - Stock Based Compensation - Activities Within the Stock Option Plan (Details) - Stock Option Plan [Member]	3 Months Ended
	Jun. 30, 2022 $ / shares $ / shares shares	Jun. 30, 2022 $ / shares shares	Jun. 30, 2021 $ / shares $ / shares shares	Jun. 30, 2021 $ / shares shares
Outstanding, weighted average exercise price (in CAD per share) | (per share)	$ 3.94			$ 8.33
Granted, weighted average exercise price (in CAD per share) | $ / shares		$ 1.15		$ 0
Outstanding, number of options (in shares)	2,989,381	2,989,381	911,871	911,871
Granted, number of options (in shares)	1,262,500	1,262,500	0	0
Exercised, weighted average exercise price (in CAD per share) | $ / shares		$ 0		$ 0
Exercised, number of options (in shares)	0	0	0	0
Forfeited, weighted average exercise price (in CAD per share) | $ / shares		$ 7.66		$ 10.35
Forfeited, number of options (in shares)	(22,263)	(22,263)	(7,995)	(7,995)
Expired, weighted average exercise price (in CAD per share) | $ / shares		$ 36.00		$ 0
Expired, number of options (in shares)	(2,113)	(2,113)	0	0
Outstanding, weighted average exercise price (in CAD per share) | $ / shares	$ 3.07		$ 8.32
Outstanding, number of options (in shares)	4,227,505	4,227,505	903,876	903,876
Exercisable, weighted average exercise price (in CAD per share) | $ / shares	$ 6.49	$ 6.49	$ 9.13	$ 9.13
Exercisable, number of options (in shares)	1,197,835	1,197,835	672,081	672,081