Note 12 - Commitments and Contingencies (Details Textual) Pure in Thousands, $ in Millions	3 Months Ended
	Jun. 30, 2025 USD ($)
Product Warranty Obligation, Term (Year)	12 years
Outstanding Purchase Orders	0
Cross License Agreement [Member]
License Agreement, Term (Year)	10 years
Land Purchase and Investment Agreement [Member]
Land Purchase and Investment Agreement, Total Value	$ 90
Kazuo AXT Investment [Member]
Land Purchase and Investment Agreement, Total Value	15
Kazuo Boyu Investment [Member]
Land Purchase and Investment Agreement, Total Value	$ 8