Note 2 - Investment Securities - Investment Securities Available for Sale (Details) $ in Thousands	Mar. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Number of investment positions - less than twelve months	74	16
Fair value - less than twelve months	$ 88,976	$ 13,489
Gross unrealized losses - less than twelve months	$ 1,503	$ 25
Number of investment positions - more than twelve months	0	4
Fair value - more than twelve months	$ 0	$ 1,589
Gross unrealized losses - more than twelve months	$ 0	$ 12
Number of investment positions	74	20
Fair value	$ 88,976	$ 15,078
Gross unrealized losses	$ 1,503	$ 37
Mortgage-backed Securities, Issued by US Government Sponsored Enterprises [Member]
Number of investment positions - less than twelve months	5
Fair value - less than twelve months	$ 8,721
Gross unrealized losses - less than twelve months	$ 96
Agency Collateralized Mortgage Obligations [Member]
Number of investment positions - less than twelve months	4	12
Fair value - less than twelve months	$ 1,935	$ 6,189
Gross unrealized losses - less than twelve months	$ 16	$ 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	13	2
Fair value - less than twelve months	$ 42,432	$ 5,997
Gross unrealized losses - less than twelve months	$ 566	$ 3
US States and Political Subdivisions Debt Securities [Member]
Number of investment positions - less than twelve months		2
Fair value - less than twelve months		$ 1,303
Gross unrealized losses - less than twelve months		$ 4
Municipal Notes [Member]
Number of investment positions - less than twelve months	52
Fair value - less than twelve months	$ 35,888
Gross unrealized losses - less than twelve months	$ 825

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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