Note 6 - Stockholders' Equity and Stock-based Compensation Expense - Stock Option and Performance Award Activity (Details)	3 Months Ended
Jun. 30, 2025 shares
Outstanding, options (in shares)	4,463,028
Options granted (in shares)	1,467,000
Options exercised (in shares)	(225,209)
Options forfeited/canceled (in shares)	(1,359,449)
Outstanding, options (in shares)	4,345,370
Performance Shares [Member]
Outstanding, performance awards (in shares)	7,142
Performance awards granted (in shares)	0
Performance awards exercised (in shares)	0
Performance awards forfeited/canceled (in shares)	0
Outstanding, performance awards (in shares)	7,142

Number of non-option equity instruments exercised by participants.

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Number of shares under non-option equity instrument agreements that were cancelled as a result of occurrence of a terminating event.

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Number of equity instruments other than options outstanding, including both vested and non-vested instruments.

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