Note 7 - Securities Available for Sale - Summary of Securities Available for Sale (Details) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Securities available for sale, amortized cost	$ 300,596	$ 287,966
Investment securities available for sale, gross unrealized gains	19	734
Investment securities available for sale, gross unrealized losses	(15,967)	(2,935)
Securities available for sale	284,648	285,765
Collateralized Mortgage-Backed Securities [Member]
Securities available for sale, amortized cost	249,903	247,275
Investment securities available for sale, gross unrealized gains	0	678
Investment securities available for sale, gross unrealized losses	(14,554)	(2,556)
Securities available for sale	235,349	245,397
Other Marketable Securities [Member]
Securities available for sale, amortized cost	50,693	40,691
Investment securities available for sale, gross unrealized gains	19	56
Investment securities available for sale, gross unrealized losses	(1,413)	(379)
Securities available for sale	49,299	40,368
Federal National Mortgage Association Certificates and Obligations (FNMA) [Member] | Collateralized Mortgage-Backed Securities [Member]
Securities available for sale, amortized cost	136,400	138,628
Investment securities available for sale, gross unrealized gains	0	550
Investment securities available for sale, gross unrealized losses	(7,671)	(1,367)
Securities available for sale	128,729	137,811
Federal National Mortgage Association Certificates and Obligations (FNMA) [Member] | Mortgage-Backed Securities, Issued by US Government Sponsored Enterprises [Member]
Securities available for sale, amortized cost	44	48
Investment securities available for sale, gross unrealized gains	0	2
Investment securities available for sale, gross unrealized losses	0	0
Securities available for sale	44	50
Federal Home Loan Mortgage Corporation Certificates and Obligations (FHLMC) [Member] | Mortgage-Backed Securities, Issued by US Government Sponsored Enterprises [Member]
Securities available for sale, amortized cost	113,459	108,599
Investment securities available for sale, gross unrealized gains	0	126
Investment securities available for sale, gross unrealized losses	(6,883)	(1,189)
Securities available for sale	106,576	107,536
US Government Agencies Debt Securities [Member] | Other Marketable Securities [Member]
Securities available for sale, amortized cost	49,993	39,991
Investment securities available for sale, gross unrealized gains	19	56
Investment securities available for sale, gross unrealized losses	(1,273)	(337)
Securities available for sale	48,739	39,710
Preferred Stock [Member] | Other Marketable Securities [Member]
Securities available for sale, amortized cost	700	700
Investment securities available for sale, gross unrealized gains	0	0
Investment securities available for sale, gross unrealized losses	(140)	(42)
Securities available for sale	$ 560	$ 658