Note 4 - Securities Available for Sale - Securities in a Continuous Unrealized Loss Position (Details) $ in Thousands	Dec. 31, 2023 USD ($)	Dec. 31, 2022 USD ($)
Less Than Twelve Months # of Investments	1	21
Less Than Twelve Months Fair Value	$ 5,000	$ 49,249
Less Than Twelve Months Unrealized Losses	$ (9)	$ (3,512)
Twelve Months or More # of Investments	66	50
Twelve Months or More Fair Value	$ 195,870	$ 196,770
Twelve Months or More Unrealized Losses	(18,495)	(22,788)
Total fair value	200,870	246,019
Total temporarily impaired securities	$ (18,504)	$ (26,300)
Mortgage Backed Securities, Issued by Us Government Sponsored Enterprises, Federal National Mortgage Association Certificates and Obligations FNMA [Member]
Less Than Twelve Months # of Investments	0	12
Less Than Twelve Months Fair Value	$ 0	$ 19,337
Less Than Twelve Months Unrealized Losses	$ 0	$ (1,629)
Twelve Months or More # of Investments	34	22
Twelve Months or More Fair Value	$ 87,133	$ 85,599
Twelve Months or More Unrealized Losses	(9,704)	(11,125)
Total fair value	87,133	104,936
Total temporarily impaired securities	$ (9,704)	$ (12,754)
Mortgage Backed Securities, Issued by Us Government Sponsored Enterprises, Federal Home Loan Mortgage Corporation Certificates and Obligations FHLMC [Member]
Less Than Twelve Months # of Investments	0	4
Less Than Twelve Months Fair Value	$ 0	$ 10,542
Less Than Twelve Months Unrealized Losses	$ 0	$ (1,214)
Twelve Months or More # of Investments	24	20
Twelve Months or More Fair Value	$ 74,249	$ 77,174
Twelve Months or More Unrealized Losses	(8,246)	(9,963)
Total fair value	74,249	87,716
Total temporarily impaired securities	$ (8,246)	$ (11,177)
Mortgage Backed Securities, Federal National Mortgage Association Certificates and Obligations FNMA [Member]
Less Than Twelve Months # of Investments	0	1
Less Than Twelve Months Fair Value	$ 0	$ 36
Less Than Twelve Months Unrealized Losses	$ 0	$ (2)
Twelve Months or More # of Investments	1	0
Twelve Months or More Fair Value	$ 32	$ 0
Twelve Months or More Unrealized Losses	(2)	0
Total fair value	32	36
Total temporarily impaired securities	$ (2)	$ (2)
Other Marketable Securities, Us Government Agencies Debt Securities [Member]
Less Than Twelve Months # of Investments	1	4
Less Than Twelve Months Fair Value	$ 5,000	$ 19,334
Less Than Twelve Months Unrealized Losses	$ (9)	$ (667)
Twelve Months or More # of Investments	7	7
Twelve Months or More Fair Value	$ 34,456	$ 33,507
Twelve Months or More Unrealized Losses	(543)	(1,490)
Total fair value	39,456	52,841
Total temporarily impaired securities	$ (552)	$ (2,157)
Other Marketable Securities, Corporate Preferred Stock [Member]
Less Than Twelve Months # of Investments		0
Less Than Twelve Months Fair Value		$ 0
Less Than Twelve Months Unrealized Losses		$ 0
Twelve Months or More # of Investments		1
Twelve Months or More Fair Value		$ 490
Twelve Months or More Unrealized Losses		(210)
Total fair value		490
Total temporarily impaired securities		$ (210)