Note 7 - Capital and Other Components of Equity (Details Textual) $ / shares in Units, $ / shares in Units, $ in Thousands					1 Months Ended		3 Months Ended			6 Months Ended		12 Months Ended
	Jun. 29, 2020 USD ($)	May 10, 2019 USD ($) shares	May 10, 2019 CAD ($) $ / shares shares	Feb. 14, 2019 USD ($)	May 31, 2019 USD ($)	May 31, 2019 CAD ($)	Sep. 30, 2020 USD ($)	Sep. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) $ / shares shares	Sep. 30, 2019 USD ($)	Mar. 31, 2019 USD ($)	Mar. 31, 2019 CAD ($)	Sep. 30, 2020 $ / shares	Sep. 30, 2020 USD ($) $ / shares shares	Mar. 31, 2020 USD ($)	May 10, 2019 $ / shares
At-the-market Sales Agreement, Common Stock, Maximum Amount	$ 75,000,000			$ 30,000,000
At-the-market Sales Agreement, Term (Year)				3 years
At-the-market Sales Agreement, Underwriter Fees, Percentage of Sales	3.00%
Proceeds from Issuance of Common Stock							$ 3,435,000			$ 5,210,000
Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs										18,000
Deferred Costs, Current, Total																$ 121,000
Write Off of Deferred Financing Costs of At-the-Market Program	$ 122,000						$ 142,000			$ 264,000
Stock Issued During Period, Value, Settlements									$ 739,000
Warrants Issued in May 2018 [Member]
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares) | shares															1
Class of Warrant or Right, Exercise Price of Warrants or Rights (in CAD per share) | $ / shares														$ 1.31
Warrants Issued December 27, 2017 [Member]
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares) | shares															1
Class of Warrant or Right, Exercise Price of Warrants or Rights (in CAD per share) | $ / shares															$ 1.26
Broker Warrants Issued May 2018 [Member]
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares) | shares															1
Class of Warrant or Right, Exercise Price of Warrants or Rights (in CAD per share) | $ / shares														1.05
Broker Warrants Issued December 2017 [Member]
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares) | shares															1
Class of Warrant or Right, Exercise Price of Warrants or Rights (in CAD per share) | $ / shares															$ 1.2625
Warrants Issued in Connection with Public Offering February 2017 [Member]
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares) | shares															1
Class of Warrant or Right, Exercise Price of Warrants or Rights (in CAD per share) | $ / shares														$ 2.15
General and Administrative Expense [Member]
Litigation Settlement, Expense												$ 786,000	$ 1,054
Former Chief Executive Officer [Member]
Stock Issued During Period, Shares, Settlements (in shares) | shares		900,000	900,000
Shares Issued, Price Per Share (in dollars per share) | (per share)			$ 1.10														$ 0.82
Legal Fees		$ 48,000	$ 64
Stock Issued During Period, Value, Settlements					$ 739,000	$ 990
Cost Incurred to Register Sales Agreement [Member]
Deferred Costs, Current, Total	$ 130,000
At-the-market Offering [Member]
Stock Issued During Period, Shares, New Issues (in shares) | shares										6,700,000
Proceeds from Issuance of Common Stock										$ 5,200,000
Commission Costs Related to Share Sale										$ 106,000
Sale of Stock, Average Price Per Share (in dollars per share) | $ / shares										$ 0.81
Minimum [Member]
At-the-market Sales Agreement, Underwriter Fees, Percentage of Sales				3.00%
Maximum [Member]
At-the-market Sales Agreement, Underwriter Fees, Percentage of Sales				4.00%