Note 3 - Investment Securities - Held to Maturity Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Securities held-to-maturity, carrying value	$ 485,449	$ 0
Securities held-to-maturity, gains	23
Securities held-to-maturity, losses	(24,626)
Debt Securities, Held-to-Maturity, Fair Value, Total	460,846	$ 0
US Treasury Securities and US Government Agencies Debt Securities [Member]
Securities held-to-maturity, carrying value	219,574
Securities held-to-maturity, gains	0
Securities held-to-maturity, losses	(4,559)
Debt Securities, Held-to-Maturity, Fair Value, Total	215,015
US Government-sponsored Enterprises Debt Securities [Member]
Securities held-to-maturity, carrying value	27,847
Securities held-to-maturity, gains	22
Securities held-to-maturity, losses	(665)
Debt Securities, Held-to-Maturity, Fair Value, Total	27,204
Mortgage-Backed Securities, Issued by US Government Sponsored Enterprises [Member]
Securities held-to-maturity, carrying value	238,028
Securities held-to-maturity, gains	1
Securities held-to-maturity, losses	(19,402)
Debt Securities, Held-to-Maturity, Fair Value, Total	$ 218,627

Amount, before allowance for credit loss, of investment in debt security measured at amortized cost (held-to-maturity).

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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Reference 3: http://www.xbrl.org/2003/role/disclosureRef
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Amount of accumulated unrecognized gain on investment in debt security measured at amortized cost (held-to-maturity).

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