Note 14 - Stock-based Compensation - Options Outstanding by Exercise Price Range (Details)	6 Months Ended
	Jun. 30, 2022 $ / shares shares
Options outstanding (in shares) | shares	465,076
Weighted average exercise price (in dollars per share)	$ 66.61
Weighted average remaining contractual life (Year)	3 years 9 months 18 days
Exercise Price Range 1 [Member]
Exercise price, lower range (in dollars per share)	$ 61.90
Options outstanding (in shares) | shares	376,681
Exercise price, upper range (in dollars per share)	$ 69.19
Weighted average exercise price (in dollars per share)	$ 64.71
Weighted average remaining contractual life (Year)	4 years
Exercise Price Range 2 [Member]
Exercise price, lower range (in dollars per share)	$ 71.64
Options outstanding (in shares) | shares	88,395
Exercise price, upper range (in dollars per share)	$ 77.92
Weighted average exercise price (in dollars per share)	$ 74.72
Weighted average remaining contractual life (Year)	2 years 10 months 24 days