Note 5 - Fair Value Measurements - Fair Value Reconciliation of Level 3 Assets (Details) - Subordinated Debt Obligations [Member] - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2023	Dec. 31, 2022
Balance		$ 8,737	$ 12,200
Purchases		1,000	500
Transfers out of Level III (1)	[1]	(1,000)	(3,750)
Net change in unrealized loss on investment securities available-for-sale		64	(213)
Balance		$ 8,801	$ 8,737

[1] Transfers between hierarchy levels are based on the availability of sufficient observable inputs to meet Level II versus Level II criteria. The level designation of each financial instrument is reassessed at the end of each period.