Note 15 - Capital Stock (Details Textual) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Aug. 31, 2025	Jul. 31, 2025	Jul. 31, 2024	Jul. 31, 2023	Dec. 20, 2024	Nov. 16, 2022	Nov. 26, 2021	May 17, 2021	May 14, 2021
Proceeds from Issuance of Common Stock		$ 287,513	$ 176,708	$ 66,527
Proceeds from Warrant Exercises		$ 3,300	$ 8,120	$ 7,550
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
Stock Issued During Period, Shares, New Issues (in shares)			26,375,699	15,171,253
Proceeds from Issuance of Common Stock			$ 171,740	$ 59,820
Payments of Stock Issuance Costs			$ 3,860	1,400
November 2022 At-the-market Offering [Member] | ATM Managers [Member]
Payments of Stock Issuance Costs				$ 1,350
2024 ATM Offering [Member]
Stock Offering, Maximum Amount					$ 300,000
2024 ATM Offering [Member] | Subsequent Event [Member]
Stock Issued During Period, Shares, New Issues (in shares)	10,077,186
Proceeds from Issuance of Common Stock	$ 101,970
Payments of Stock Issuance Costs	$ 2,290
The 2022 and 2024 ATM Offerings [Member]
Stock Issued During Period, Shares, New Issues (in shares)		41,764,036
Proceeds from Issuance of Common Stock		$ 292,350
Payments of Stock Issuance Costs		6,600
The 2022 and 2024 ATM Offerings [Member] | ATM Managers [Member]
Payments of Stock Issuance Costs		$ 6,580