Note 3 - Investment Securities - Investment Securities Available for Sale (Details) $ in Thousands	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Number of investment positions - less than twelve months	122	16
Fair value - less than twelve months	$ 247,386	$ 13,489
Gross unrealized losses - less than twelve months	$ 3,341	$ 25
Number of investment positions - more than twelve months	9	4
Fair value - more than twelve months	$ 17,990	$ 1,589
Gross unrealized losses - more than twelve months	$ 456	$ 12
Number of investment positions	131	20
Fair value	$ 265,376	$ 15,078
Gross unrealized losses	$ 3,797	$ 37
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Number of investment positions - less than twelve months	23
Fair value - less than twelve months	$ 67,512
Gross unrealized losses - less than twelve months	$ 607
Number of investment positions - more than twelve months	1
Fair value - more than twelve months	$ 1,357
Gross unrealized losses - more than twelve months	$ 28
Agency Collateralized Mortgage Obligations [Member]
Number of investment positions - less than twelve months		12
Fair value - less than twelve months		$ 6,189
Gross unrealized losses - less than twelve months		$ 18
Number of investment positions - more than twelve months		4
Fair value - more than twelve months		$ 1,589
Gross unrealized losses - more than twelve months		$ 12
US Government Agencies Debt Securities [Member]
Number of investment positions - less than twelve months	39	2
Fair value - less than twelve months	$ 98,042	$ 5,997
Gross unrealized losses - less than twelve months	$ 1,710	$ 3
Number of investment positions - more than twelve months	4
Fair value - more than twelve months	$ 13,676
Gross unrealized losses - more than twelve months	$ 324
US Treasury and Government [Member]
Number of investment positions - less than twelve months	11
Fair value - less than twelve months	$ 49,190
Gross unrealized losses - less than twelve months	$ 545
US States and Political Subdivisions Debt Securities [Member]
Number of investment positions - less than twelve months	49	2
Fair value - less than twelve months	$ 32,642	$ 1,303
Gross unrealized losses - less than twelve months	$ 479	$ 4
Municipal Notes [Member]
Number of investment positions - more than twelve months	4
Fair value - more than twelve months	$ 2,957
Gross unrealized losses - more than twelve months	$ 104

Amount of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale), in continuous unrealized loss position for more than 12 months, without allowance for credit loss. Includes beneficial interest in securitized financial asset.

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