Note 6 - Stockholders' Equity and Stock-based Compensation Expense - Stock Option and Performance Award Activity (Details)	3 Months Ended
Mar. 31, 2025 shares
Outstanding, options (in shares)	4,463,028
Options granted (in shares)	0
Options exercised (in shares)	(225,209)
Options forfeited/canceled (in shares)	(959,051)
Outstanding, options (in shares)	3,278,768
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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