Note 6 - Securities - Securities Available-for-sale (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Amortized cost	$ 1,022,443	$ 627,380
Gross unrealized gains	8,160	13,583
Gross unrealized losses	9,542	358
Fair value	1,021,061	640,605
US Treasury Securities [Member]
Amortized cost	22,751
Gross unrealized gains	0
Gross unrealized losses	437
Fair value	22,314
US Government Agencies Debt Securities [Member]
Amortized cost	27,867	2,567
Gross unrealized gains	2	5
Gross unrealized losses	376	0
Fair value	27,493	2,572
Corporate Debt Securities [Member]
Amortized cost	45,876	38,738
Gross unrealized gains	812	380
Gross unrealized losses	106	5
Fair value	46,582	39,113
Collateralized Mortgage Backed Securities [Member]
Amortized cost	555,528	288,373
Gross unrealized gains	3,246	6,893
Gross unrealized losses	6,435	247
Fair value	552,339	295,019
US States and Political Subdivisions Debt Securities [Member]
Amortized cost	370,421	296,262
Gross unrealized gains	4,100	6,097
Gross unrealized losses	2,188	106
Fair value	$ 372,333	302,253
Other Debt Obligations [Member]
Amortized cost		1,440
Gross unrealized gains		208
Gross unrealized losses		0
Fair value		$ 1,648

Amount, before tax, of unrealized gain in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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