Note 13 - Capital Stock - Summary of Stock Options Outstanding and Exercisable (Details) - $ / shares	9 Months Ended
	Apr. 30, 2022	Jan. 31, 2022	Oct. 31, 2021	Jul. 31, 2021
Options Outstanding (in shares)	7,881,351	9,063,956	9,323,790	10,404,333
Options outstanding, weighted average exercise price (in dollars per share)	$ 1.21	$ 1.20	$ 1.20	$ 1.21
Options outstanding, weighted average remaining contractual term (Year)	6 years 8 months 26 days
Options exercisable (in shares)	5,327,391
Options exercisable, weighted average exercise price (in dollars per share)	$ 1.14
Options exercisable, weighted average remaining contractual term (Year)	5 years 10 months 24 days
Exercise Price Range 1 [Member]
Range of Exercise Prices, Lower Limit (in dollars per share)	$ 0.80
Range of Exercise Prices, Upper Limit (in dollars per share)	$ 0.99
Options Outstanding (in shares)	4,121,936
Options outstanding, weighted average exercise price (in dollars per share)	$ 0.92
Options outstanding, weighted average remaining contractual term (Year)	7 years 9 months 18 days
Options exercisable (in shares)	3,167,875
Options exercisable, weighted average exercise price (in dollars per share)	$ 0.92
Options exercisable, weighted average remaining contractual term (Year)	7 years 8 months 4 days
Exercise Price Range 2 [Member]
Range of Exercise Prices, Lower Limit (in dollars per share)	$ 1.00
Range of Exercise Prices, Upper Limit (in dollars per share)	$ 1.49
Options Outstanding (in shares)	1,796,875
Options outstanding, weighted average exercise price (in dollars per share)	$ 1.15
Options outstanding, weighted average remaining contractual term (Year)	6 years 1 month 28 days
Options exercisable (in shares)	913,541
Options exercisable, weighted average exercise price (in dollars per share)	$ 1.20
Options exercisable, weighted average remaining contractual term (Year)	4 years 2 months 1 day
Exercise Price Range 3 [Member]
Range of Exercise Prices, Lower Limit (in dollars per share)	$ 1.50
Range of Exercise Prices, Upper Limit (in dollars per share)	$ 2.89
Options Outstanding (in shares)	1,962,540
Options outstanding, weighted average exercise price (in dollars per share)	$ 1.86
Options outstanding, weighted average remaining contractual term (Year)	5 years 10 days
Options exercisable (in shares)	1,245,975
Options exercisable, weighted average exercise price (in dollars per share)	$ 1.65
Options exercisable, weighted average remaining contractual term (Year)	2 years 7 months 17 days