Note 7 - Securities Available for Sale - Securities in a Continuous Unrealized Loss Position (Details) $ in Thousands	Jun. 30, 2022 USD ($)	Dec. 31, 2021 USD ($)
Less Than Twelve Months # of Investments	49	43
Less Than Twelve Months Fair Value	$ 197,864	$ 218,706
Less Than Twelve Months Unrealized Losses	$ (16,603)	$ (2,609)
Twelve Months or More # of Investments	22	5
Twelve Months or More Fair Value	$ 71,492	$ 15,132
Twelve Months or More Unrealized Losses	(7,281)	(326)
Total fair value	269,356	233,838
Total temporarily impaired securities	$ (23,884)	$ (2,935)
Collateralized Mortgage-Backed Securities [Member] | Federal National Mortgage Association Certificates and Obligations (FNMA) [Member]
Less Than Twelve Months # of Investments	24	19
Less Than Twelve Months Fair Value	$ 86,229	$ 98,423
Less Than Twelve Months Unrealized Losses	$ (8,369)	$ (1,234)
Twelve Months or More # of Investments	10	2
Twelve Months or More Fair Value	$ 31,182	$ 6,810
Twelve Months or More Unrealized Losses	(3,580)	(133)
Total fair value	117,411	105,233
Total temporarily impaired securities	$ (11,949)	$ (1,367)
Collateralized Mortgage-Backed Securities [Member] | Federal Home Loan Mortgage Corporation Certificates and Obligations (FHLMC) [Member]
Less Than Twelve Months # of Investments	16	17
Less Than Twelve Months Fair Value	$ 72,652	$ 85,624
Less Than Twelve Months Unrealized Losses	$ (7,177)	$ (1,038)
Twelve Months or More # of Investments	8	2
Twelve Months or More Fair Value	$ 25,400	$ 7,664
Twelve Months or More Unrealized Losses	(2,913)	(151)
Total fair value	98,052	93,288
Total temporarily impaired securities	$ (10,090)	$ (1,189)
Collateralized Mortgage Obligations [Member] | Federal National Mortgage Association Certificates and Obligations (FNMA) [Member]
Less Than Twelve Months # of Investments	1
Less Than Twelve Months Fair Value	$ 41
Less Than Twelve Months Unrealized Losses	$ (1)
Twelve Months or More # of Investments	0
Twelve Months or More Fair Value	$ 0
Twelve Months or More Unrealized Losses	0
Total fair value	41
Total temporarily impaired securities	$ (1)
Other Marketable Securities [Member] | US Government Agencies Debt Securities [Member]
Less Than Twelve Months # of Investments	8	7
Less Than Twelve Months Fair Value	$ 38,942	$ 34,659
Less Than Twelve Months Unrealized Losses	$ (1,056)	$ (337)
Twelve Months or More # of Investments	3	0
Twelve Months or More Fair Value	$ 14,385	$ 0
Twelve Months or More Unrealized Losses	(613)	0
Total fair value	53,327	34,659
Total temporarily impaired securities	$ (1,669)	$ (337)
Other Marketable Securities [Member] | Preferred Stock [Member]
Less Than Twelve Months # of Investments	0	0
Less Than Twelve Months Fair Value	$ 0	$ 0
Less Than Twelve Months Unrealized Losses	$ 0	$ 0
Twelve Months or More # of Investments	1	1
Twelve Months or More Fair Value	$ 525	$ 658
Twelve Months or More Unrealized Losses	(175)	(42)
Total fair value	525	658
Total temporarily impaired securities	$ (175)	$ (42)