Note 7 - Securities Available for Sale - Summary of Securities Available for Sale (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Securities available for sale, amortized cost	$ 235,252	$ 146,312
Investment securities available for sale, gross unrealized gains	1,008	1,851
Investment securities available for sale, gross unrealized losses	(1,321)	(73)
Securities available for sale	234,939	148,090
Collateralized Mortgage Backed Securities [Member]
Securities available for sale, amortized cost	194,562	99,821
Investment securities available for sale, gross unrealized gains	925	1,646
Investment securities available for sale, gross unrealized losses	(1,180)	(3)
Securities available for sale	194,307	101,464
Other Marketable Securities [Member]
Securities available for sale, amortized cost	40,690	46,491
Investment securities available for sale, gross unrealized gains	83	205
Investment securities available for sale, gross unrealized losses	(141)	(70)
Securities available for sale	40,632	46,626
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	111,267	68,699
Investment securities available for sale, gross unrealized gains	751	1,313
Investment securities available for sale, gross unrealized losses	(663)	(3)
Securities available for sale	111,355	70,009
Federal National Mortgage Association Certificates and Obligations (FNMA) [Member] \| Collateralized Mortgage Obligations [Member]
Securities available for sale, amortized cost	51	97
Investment securities available for sale, gross unrealized gains	2	6
Investment securities available for sale, gross unrealized losses	0	0
Securities available for sale	53	103
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	83,244	31,025
Investment securities available for sale, gross unrealized gains	172	327
Investment securities available for sale, gross unrealized losses	(517)	0
Securities available for sale	82,899	31,352
US Government Agencies Debt Securities [Member] \| Other Marketable Securities [Member]
Securities available for sale, amortized cost	39,990	45,029
Investment securities available for sale, gross unrealized gains	83	204
Investment securities available for sale, gross unrealized losses	(85)	0
Securities available for sale	39,988	45,233
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	(56)	(70)
Securities available for sale	$ 644	630
US States and Political Subdivisions Debt Securities [Member] \| Other Marketable Securities [Member]
Securities available for sale, amortized cost		725
Investment securities available for sale, gross unrealized gains		1
Investment securities available for sale, gross unrealized losses		0
Securities available for sale		726
Corporate Debt Securities [Member] \| Other Marketable Securities [Member]
Securities available for sale, amortized cost		37
Investment securities available for sale, gross unrealized gains		0
Investment securities available for sale, gross unrealized losses		0
Securities available for sale		$ 37

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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