Note 5 - Fair Value Measurements - Fair Value Reconciliation of Level 3 Assets (Details) - Subordinated Debt Obligations [Member] $ in Thousands	9 Months Ended
	Sep. 30, 2022 USD ($)
Balance as of January 1, 2022	$ 12,200
Transfers into Level III (1)	500
Transfers out of Level III (1)	(2,250)	[1]
Net unrealized holding gain on available-for-sale investment securities	(303)
Balance as of September 30, 2022	$ 10,147

[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.