Note 15 - Income Taxes - Net Operating Loss Carry-forwards Expirations (Details) - Jul. 31, 2020	USD ($)	CAD ($)
Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
Net Operating Loss Carry-forwards Subject to Expiration	$ 167,299,520
Foreign Tax Authority [Member] | Canada Revenue Agency [Member]
Net Operating Loss Carry-forwards Subject to Expiration		$ 5,051,867
Tax Year 2023 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
Net Operating Loss Carry-forwards Subject to Expiration	180,892
Tax Year 2027 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
Net Operating Loss Carry-forwards Subject to Expiration	3,892,722
Tax Year 2027 [Member] | Foreign Tax Authority [Member] | Canada Revenue Agency [Member]
Net Operating Loss Carry-forwards Subject to Expiration		183,105
Tax Year 2024 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
Net Operating Loss Carry-forwards Subject to Expiration	228,757
Tax Year 2028 [Member] | Foreign Tax Authority [Member] | Canada Revenue Agency [Member]
Net Operating Loss Carry-forwards Subject to Expiration		629,788
Tax Year 2025 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
Net Operating Loss Carry-forwards Subject to Expiration	507,833
Tax Year 2029 [Member] | Foreign Tax Authority [Member] | Canada Revenue Agency [Member]
Net Operating Loss Carry-forwards Subject to Expiration		769,072
Tax Year 2026 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
Net Operating Loss Carry-forwards Subject to Expiration	5,895,221
Tax Year 2030 [Member] | Foreign Tax Authority [Member] | Canada Revenue Agency [Member]
Net Operating Loss Carry-forwards Subject to Expiration		764,230
Tax Year 2031 [Member] | Foreign Tax Authority [Member] | Canada Revenue Agency [Member]
Net Operating Loss Carry-forwards Subject to Expiration		1,747,548
Remaining [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
Net Operating Loss Carry-forwards Subject to Expiration	$ 156,594,095
Remaining [Member] | Foreign Tax Authority [Member] | Canada Revenue Agency [Member]
Net Operating Loss Carry-forwards Subject to Expiration		$ 958,124