Note 11 - Capital Stock (Details Textual) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Jul. 30, 2024	Apr. 30, 2024	Apr. 30, 2024	Nov. 16, 2022	Nov. 26, 2021	May 17, 2021	May 14, 2021
Proceeds from Warrant Exercises		$ 3,771	$ 4,508
Class of Warrant or Right Exercised (in shares)			1,452,914
Subsequent Event [Member]
Proceeds from Warrant Exercises	$ 93
Class of Warrant or Right Exercised (in shares)	39,393
Shelf 2021 [Member]
Stock Offering, Maximum Amount					$ 200,000	$ 200,000
May 17, 2021 At-the-market Offering [Member]
Stock Offering, Maximum Amount						$ 100,000
May 14, 2021 At-the-market Offering [Member]
Stock Offering, Maximum Amount							$ 100,000
November 2021 At-the-market Offering [Member]
Stock Offering, Maximum Amount					$ 100,000
Shelf 2022 [Member]
Stock Offering, Maximum Amount				$ 300,000
November 2022 At-the-market Offering [Member]
Stock Offering, Maximum Amount				$ 300,000
At-the-market Offering [Member]
Stock Issued During Period, Shares, New Issues (in shares)		3,396,370	24,584,399
Proceeds from Issuance of Common Stock, Net		$ 25,542	$ 155,050
At-the-market Offering [Member] | Subsequent Event [Member]
Stock Issued During Period, Shares, New Issues (in shares)	1,791,300
Proceeds from Issuance of Common Stock, Net	$ 12,824