Note 5 - Financial Instruments and Fair Value Measurements - Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Mar. 31, 2026	Dec. 31, 2025
Fair Value, Inputs, Level 1 [Member] \| Reported Value Measurement [Member]
Cash and cash equivalents	$ 201,603	$ 232,179
Fair Value, Inputs, Level 1 [Member] \| Estimate of Fair Value Measurement [Member]
Cash and cash equivalents	201,603	232,179
Fair Value, Inputs, Level 2 [Member] \| Reported Value Measurement [Member]
Restricted equity securities	7,061	7,061
Interest receivable	8,473	8,879
Interest payable	(306)	(268)
Fair Value, Inputs, Level 2 [Member] \| Estimate of Fair Value Measurement [Member]
Restricted equity securities	7,061	7,061
Interest receivable	8,473	8,879
Interest payable	(306)	(268)
Fair Value, Inputs, Level 3 [Member] \| Reported Value Measurement [Member]
Loans, net	1,132,713	1,129,606
Deposits	(1,780,996)	(1,792,962)
Fair Value, Inputs, Level 3 [Member] \| Estimate of Fair Value Measurement [Member]
Loans, net		1,085,650
Deposits	$ (1,780,767)	$ (1,792,794)

Fair value portion of deposit liabilities held by the entity, including, but not limited to, foreign and domestic, interest and noninterest bearing, demand deposits, saving deposits, negotiable orders of withdrawal (NOW) and time deposits.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2

Reference 3: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-11

Reference 4: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 11
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-11

Reference 5: http://www.xbrl.org/2003/role/disclosureRef
-Topic 825
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 10
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482907/825-10-50-10

Reference 6: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 820
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2E
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482106/820-10-50-2E

Name:	us-gaap_DepositsFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant