Note 7 - Commitments and Contingencies - Commitments and Contingent Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Commitments	$ 281,386	$ 267,831
Standby Letters of Credit [Member]
Commitments	4,925	4,423
Federal Home Loan Bank of San Francisco Affordable Housing Grant Sponsorships [Member]
Commitments	3,338	3,338
AHEAD Grants [Member]
Commitments	90	90
Commitments to Extend Credit [Member]
Commitments	$ 273,033	$ 259,980