Note 6 - Stock-based Compensation - Restricted Stock Units (Details)	3 Months Ended
	Mar. 31, 2024 $ / shares shares
Time-based Restricted Stock Units [Member]
Balance (in shares) | shares	194,389
Balance, weighted-average grant date fair value (in dollars per share) | $ / shares	$ 34.83
Granted (in shares) | shares	1,241
Granted, weighted-average grant date fair value (in dollars per share) | $ / shares	$ 37.96
Vested (in shares) | shares	(1,326)
Vested, weighted-average grant date fair value (in dollars per share) | $ / shares	$ 43.24
Forfeited (in shares) | shares	(16,400)
Forfeited, weighted-average grant date fair value (in dollars per share) | $ / shares	$ 41.94
Balance (in shares) | shares	177,904
Balance, weighted-average grant date fair value (in dollars per share) | $ / shares	$ 34.13
Performance-based Restricted Stock Units [Member]
Balance (in shares) | shares	349,661
Balance, weighted-average grant date fair value (in dollars per share) | $ / shares	$ 32.94
Granted (in shares) | shares	0
Granted, weighted-average grant date fair value (in dollars per share) | $ / shares	$ 0
Vested (in shares) | shares	0
Vested, weighted-average grant date fair value (in dollars per share) | $ / shares	$ 0
Forfeited (in shares) | shares	(17,395)
Forfeited, weighted-average grant date fair value (in dollars per share) | $ / shares	$ 39.26
Balance (in shares) | shares	332,266
Balance, weighted-average grant date fair value (in dollars per share) | $ / shares	$ 32.61