Note 14 - Capital Stock - Warrants Assumptions (Details)	Apr. 30, 2021 yr
Warrant Issued with September 2020 Offering [Member] | Measurement Input, Risk Free Interest Rate [Member]
Warrants, measurement input	0.0014
Warrant Issued with September 2020 Offering [Member] | Measurement Input, Price Volatility [Member]
Warrants, measurement input	0.7681
Warrant Issued with September 2020 Offering [Member] | Measurement Input, Expected Term [Member]
Warrants, measurement input	2
Warrant Issued with September 2020 Offering [Member] | Measurement Input, Expected Dividend Rate [Member]
Warrants, measurement input	0
Warrant Issued to Agents [Member] | Measurement Input, Risk Free Interest Rate [Member]
Warrants, measurement input	0.0085
Warrant Issued to Agents [Member] | Measurement Input, Price Volatility [Member]
Warrants, measurement input	0.7217
Warrant Issued to Agents [Member] | Measurement Input, Expected Term [Member]
Warrants, measurement input	5
Warrant Issued to Agents [Member] | Measurement Input, Expected Dividend Rate [Member]
Warrants, measurement input	0