Note 12 - Stock-based Compensation - Schedule of Outstanding Stock Options (Details)	9 Months Ended
	Apr. 30, 2019 $ / shares shares
Balance outstanding (in shares) | shares	14,911,625
Balance, Weighted Average Exercise Price (in dollars per share) | $ / shares	$ 1.41
Granted (in shares) | shares	130,000
Granted, Weighted Average Exercise Price (in dollars per share) | $ / shares	$ 1.38
Exercised (in shares) | shares	(217,750)
Exercised Options, Weighted Average Exercise Price (in dollars per share) | $ / shares	$ 1.11
Forfeited (in shares) | shares	(87,500)
Forfeited, Weighted Average Exercise Price (in dollars per share) | $ / shares	$ 1.42
Balance outstanding (in shares) | shares	14,736,375
Balance, Weighted Average Exercise Price (in dollars per share) | $ / shares	$ 1.41