Note 15 - Income Taxes - Net Operating Loss Carry-forwards Expirations (Details) - Jul. 31, 2019	USD ($)	CAD ($)
Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
Net Operating Loss Carry-forwards Subject to Expiration	$ 166,608,883
Foreign Tax Authority [Member] | Canada Revenue Agency [Member]
Net Operating Loss Carry-forwards Subject to Expiration		$ 5,241,381
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] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
Net Operating Loss Carry-forwards Subject to Expiration	9,913,533
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] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
Net Operating Loss Carry-forwards Subject to Expiration	8,469,032
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] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
Net Operating Loss Carry-forwards Subject to Expiration	7,319,644
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] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
Net Operating Loss Carry-forwards Subject to Expiration	14,954,064
Tax Year 2031 [Member] | Foreign Tax Authority [Member] | Canada Revenue Agency [Member]
Net Operating Loss Carry-forwards Subject to Expiration		1,914,943
Tax Year 2032 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
Net Operating Loss Carry-forwards Subject to Expiration	15,547,890
Tax Year 2032 [Member] | Foreign Tax Authority [Member] | Canada Revenue Agency [Member]
Net Operating Loss Carry-forwards Subject to Expiration		761,843
Tax Year 2033 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
Net Operating Loss Carry-forwards Subject to Expiration	16,865,884
Tax Year 2033 [Member] | Foreign Tax Authority [Member] | Canada Revenue Agency [Member]
Net Operating Loss Carry-forwards Subject to Expiration		69,854
Tax Year 2034 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
Net Operating Loss Carry-forwards Subject to Expiration	22,139,423
Tax Year 2034 [Member] | Foreign Tax Authority [Member] | Canada Revenue Agency [Member]
Net Operating Loss Carry-forwards Subject to Expiration		61,769
Tax Year 2035 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
Net Operating Loss Carry-forwards Subject to Expiration	19,891,560
Tax Year 2035 [Member] | Foreign Tax Authority [Member] | Canada Revenue Agency [Member]
Net Operating Loss Carry-forwards Subject to Expiration		41,173
Tax Year 2036 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
Net Operating Loss Carry-forwards Subject to Expiration	19,024,525
Tax Year 2036 [Member] | Foreign Tax Authority [Member] | Canada Revenue Agency [Member]
Net Operating Loss Carry-forwards Subject to Expiration		9,917
Tax Year 2037 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
Net Operating Loss Carry-forwards Subject to Expiration	20,396,629
Tax Year 2037 [Member] | Foreign Tax Authority [Member] | Canada Revenue Agency [Member]
Net Operating Loss Carry-forwards Subject to Expiration
Tax Year 2038 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
Net Operating Loss Carry-forwards Subject to Expiration	690,637
Tax Year 2038 [Member] | Foreign Tax Authority [Member] | Canada Revenue Agency [Member]
Net Operating Loss Carry-forwards Subject to Expiration		6,511
Tax Year 2039 [Member] | Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
Net Operating Loss Carry-forwards Subject to Expiration	$ 690,637
Tax Year 2039 [Member] | Foreign Tax Authority [Member] | Canada Revenue Agency [Member]
Net Operating Loss Carry-forwards Subject to Expiration		$ 29,176