Note 18 - Equity Incentive Plans - Restricted Stock Units (Details) - $ / shares	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Time-based Restricted Stock Units [Member]
Balance (in shares)	292,670	273,200	284,493
Balance, weighted-average grant date fair value (in dollars per share)	$ 33.37	$ 35.90	$ 35.79
Granted (in shares)	63,467	110,495	108,925
Granted, weighted-average grant date fair value (in dollars per share)	$ 41.18	$ 21.79	$ 36.37
Vested (in shares)	(96,869)	(80,654)	(93,729)
Vested, weighted-average grant date fair value (in dollars per share)	$ 41.72	$ 25.34	$ 35.14
Forfeited (in shares)	(23,324)	(10,371)	(26,489)
Forfeited, weighted-average grant date fair value (in dollars per share)	$ 29.92	$ 39.04	$ 39.34
Balance (in shares)	235,944	292,670	273,200
Balance, weighted-average grant date fair value (in dollars per share)	$ 32.38	$ 33.37	$ 35.90
Performance-based Restricted Stock Units [Member]
Balance (in shares)	302,802	297,744	265,659
Balance, weighted-average grant date fair value (in dollars per share)	$ 32.55	$ 32.65	$ 32.90
Granted (in shares)	113,764	212,369	124,586
Granted, weighted-average grant date fair value (in dollars per share)	$ 37.13	$ 22.96	$ 36.37
Vested (in shares)	(76,292)	(193,240)	(92,501)
Vested, weighted-average grant date fair value (in dollars per share)	$ 41.69	$ 21.68	$ 38.36
Forfeited (in shares)	(7,768)	(14,071)	0
Forfeited, weighted-average grant date fair value (in dollars per share)	$ 40.85	$ 39.08	$ 0
Balance (in shares)	332,506	302,802	297,744
Balance, weighted-average grant date fair value (in dollars per share)	$ 31.82	$ 32.55	$ 32.65