Note 13 - Commitments and Off-balance-sheet Risk - Instruments Carried at Fair Values (Details) - USD ($)	Dec. 31, 2021	Dec. 31, 2020
Contractual amounts of financial instruments with off-balance sheet risk	$ 1,565,871,000	$ 1,430,195,000
Standby Letters of Credit [Member]
Standby letters of credit, contract amount	33,109,000	20,543,000
Contractual amounts of financial instruments with off-balance sheet risk	$ 212,000	$ 138,000