Note 11 - Derivative Warrant Liabilities - Changes in Fair Value (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Warrants Issued in May 2018 [Member]
Balance – beginning of year	$ 2,597	$ 1,146
Change in fair value	(2,580)	1,252
Translation effect	(7)	199
Balance – end of year	$ 10	$ 2,597
Fair value per warrant issuable (in dollars per share)	$ 0.01	$ 3.15
Warrants Issued December 2017 [Member]
Balance – beginning of year	$ 2,622	$ 1,247
Change in fair value	$ (2,622)	1,174
Translation effect		201
Balance – end of year		$ 2,622
Fair value per warrant issuable (in dollars per share)		$ 2.97