Note 7 - Capital and Other Components of Equity (Details Textual)		3 Months Ended	9 Months Ended
	Jun. 29, 2020 USD ($) shares	Dec. 31, 2021 USD ($) shares	Dec. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2021 USD ($) shares	Dec. 31, 2022 $ / shares shares	Nov. 10, 2021 USD ($)
At-the-market Sales Agreement, Common Stock, Maximum Amount | $	$ 75,000,000					$ 75,000,000
At-the-market Sales Agreement, Underwriter Fees, Percentage of Sales	3.00%
Warrants Issued in May 2018 [Member]
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares) | shares			1		1
Class of Warrant or Right, Exercise Price of Warrants or Rights (in CAD per share) | $ / shares					$ 10.48
Warrants Issued December 27, 2017 [Member]
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares) | shares			1		1
Class of Warrant or Right, Exercise Price of Warrants or Rights (in CAD per share) | $ / shares			$ 10.08
Broker Warrants Issued May 2018 [Member]
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares) | shares			1		1
Class of Warrant or Right, Exercise Price of Warrants or Rights (in CAD per share) | $ / shares			$ 10.10
At-the-market Offering [Member]
Stock Issued During Period, Shares, New Issues (in shares) | shares	0	0	324,648	0
Proceeds from Issuance of Common Stock, Net | $			$ 314,000
Commission Costs Related to Share Sale | $			$ 10,000
Sale of Stock, Average Price Per Share (in dollars per share) | $ / shares			$ 0.95
Cost related to prospectus supplement amount | $		$ 198,000		$ 198,000