Note 6 - Equity Incentive Plans - Summary of Performance Shares Activity (Details) - Performance-based Vesting Restricted Stock Units [Member]	6 Months Ended
	Jun. 30, 2023 $ / shares shares
Outstanding, shares (in shares) | shares	0
Outstanding, weighted average grant date fair value (in dollars per share) | $ / shares	$ 0
Granted , shares (in shares) | shares	1,107
Granted, weighted average grant date fair value (in dollars per share) | $ / shares	$ 67.85
Vested, shares (in shares) | shares	0
Vested, weighted average grant date fair value (in dollars per share) | $ / shares	$ 0
Forfeited or expired, shares (in shares) | shares	0
Forfeited or expired, weighted average grant date fair value (in dollars per share) | $ / shares	$ 0
Outstanding, shares (in shares) | shares	1,107
Outstanding, weighted average grant date fair value (in dollars per share) | $ / shares	$ 67.85
Grant price (in dollars per share) | $ / shares	$ 67.85
PSU outstanding (in shares) | shares	1,107