Note 5 - Deposits - Summary of Deposits (Details) - USD ($)	3 Months Ended
	Mar. 31, 2023	Dec. 31, 2022
Noninterest-bearing	$ 1,376,782,000	$ 1,604,750,000
Noninterest-bearing demand, percentage	38.30%	43.20%
Noninterest-bearing demand, percent increase (decrease)	(14.20%)
Interest-bearing checking	$ 576,678,000	$ 575,028,000
Interest-bearing checking, percentage	16.00%	15.50%
Interest-bearing checking, percent increase (decrease)	0.30%
Money market	$ 842,557,000	$ 776,723,000
Money market, percentage	23.40%	20.90%
Money market, percent increase (decrease)	8.50%
Savings	$ 340,178,000	$ 381,602,000
Savings, percentage	9.50%	10.30%
Savings, percent increase (decrease)	(10.90%)
Local Time, under $100,000	$ 132,482,000	$ 113,099,000
Local Time, under $100,000, percentage	3.70%	3.00%
Local Time, under $100,000, percent increase (decrease)	17.10%
Local Time, $100,000 and over	$ 329,341,000	$ 261,609,000
Local Time, $100,000 and over, percentage	9.10%	7.10%
Local Time, $100,000 and over, percent increase (decrease)	25.90%
Total deposits	$ 3,598,018,000	$ 3,712,811,000
Total deposits, percentage	100.00%	100.00%
Total deposits, percent increase (decrease)	(3.10%)