Note 14 - Fair Value Measurements - Changes in Level 3 Assets (Details) - Fair Value, Inputs, Level 3 [Member] - Fair Value, Recurring [Member] - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2021		Dec. 31, 2020
Balance at Beginning of Period	$ 8,912
Transfers Into Level 3	(8,912)	[1]	$ 1,540
Purchases	0		7,372
Unrealized	0
Total	0		8,912
Corporate Debt Securities [Member]
Balance at Beginning of Period	2,540		0
Transfers Into Level 3	(2,540)	[1]	1,540	[2]
Purchases	0		1,000
Unrealized	0		0
Total	0		2,540
Mortgage-backed Securities, Issued by Private Enterprises [Member]
Balance at Beginning of Period	6,372		0
Transfers Into Level 3	(6,372)	[1]	0	[2]
Purchases	0		6,372
Unrealized	0		0
Total	$ 0		$ 6,372

[1] Transferred from Level 3 to Level 2 after obtaining observable market data.

[2] Transferred from Level 2 to Level 3 because of a lack of observable market data, resulting from little to no market activity for the securities.