Note 3 - Acquisitions (Details Textual) - USD ($)			9 Months Ended
	Jan. 14, 2022	Jan. 04, 2022	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets, Total	$ 8,495,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents	312,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Assets	52,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities, Total	81,790,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Financial Liabilities	81,700,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Liabilities	88,000
Payments to Acquire Businesses, Net of Cash Acquired, Total	(71,040,000)		$ (71,352,000)	$ (0)
Goodwill, Ending Balance			$ 71,498,000		$ 69,243,000
Acquisition of the Honolulu, Hawaii Branch Office of the Bank of the Orient [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Assets, Total	8,500,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents	312,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Selected Performing Loans	7,400,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Assets	64,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities, Total	81,800,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Financial Liabilities	81,700,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Certificate of Deposit Premium	27,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Liabilities	90,000
Payments to Acquire Businesses, Net of Cash Acquired, Total		$ (71,000,000.0)
Goodwill, Ending Balance	2,300,000
Acquisition of the Honolulu, Hawaii Branch Office of the Bank of the Orient [Member] | Financial Asset Acquired with Credit Deterioration [Member]
Business Combination, Acquired Receivable, Fair Value	0
Acquisition of the Honolulu, Hawaii Branch Office of the Bank of the Orient [Member] | Core Deposits [Member]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Finite-Lived Intangibles	$ 729,000