Note 4 - Investment Securities - Amortized Cost and Fair Value of Available for Sale Securities and Held to Maturity Securities (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Available for sale, amortized cost	$ 380,855	$ 370,613
Available for sale, gross unrealized gains	15	741
Available for sale, gross unrealized losses	(22,735)	(3,094)
Available for sale	358,135	368,260
Held to maturity (fair value of $5,615 and $6,577 at June 30, 2022 and December 31, 2021, respectively)	5,741	6,252
Held to maturity, gross unrealized gains	20	325
Held to maturity, gross unrealized losses	146	0
Securities held to maturity, fair value	5,615	6,577
Held to maturity, gross unrealized losses	(146)	0
US Government Agencies Debt Securities [Member]
Available for sale, amortized cost	5,364	5,689
Available for sale, gross unrealized gains	0	4
Available for sale, gross unrealized losses	(373)	(83)
Available for sale	4,991	5,610
Small Business Administration Agency Securities [Member]
Available for sale, amortized cost	2,877	3,351
Available for sale, gross unrealized gains	0	118
Available for sale, gross unrealized losses	(127)	0
Available for sale	2,750	3,469
Mortgage-Backed Securities, Issued by US Government Sponsored Enterprises [Member]
Available for sale, amortized cost	52,299	55,534
Available for sale, gross unrealized gains	0	31
Available for sale, gross unrealized losses	(4,909)	(540)
Available for sale	47,390	55,025
Collateralized Mortgage Obligations [Member]
Available for sale, amortized cost	137,776	121,377
Available for sale, gross unrealized gains	9	128
Available for sale, gross unrealized losses	(10,572)	(1,994)
Available for sale	127,213	119,511
Commercial Paper [Member]
Available for sale, amortized cost	128,655	129,962
Available for sale, gross unrealized gains	0	0
Available for sale, gross unrealized losses	(182)	(36)
Available for sale	128,473	129,926
Corporate Debt Securities [Member]
Available for sale, amortized cost	41,198	41,999
Available for sale, gross unrealized gains	6	460
Available for sale, gross unrealized losses	(2,960)	(254)
Available for sale	38,244	42,205
Municipal Bonds [Member]
Available for sale, amortized cost	12,686	12,701
Available for sale, gross unrealized gains	0	0
Available for sale, gross unrealized losses	(3,612)	(187)
Available for sale	9,074	12,514
Held to maturity (fair value of $5,615 and $6,577 at June 30, 2022 and December 31, 2021, respectively)	4,736	4,746
Held to maturity, gross unrealized gains	0	248
Held to maturity, gross unrealized losses	146	0
Securities held to maturity, fair value	4,590	4,994
Held to maturity, gross unrealized losses	(146)	0
Taxable Municipal Bonds [Member]
Held to maturity (fair value of $5,615 and $6,577 at June 30, 2022 and December 31, 2021, respectively)	1,005	1,506
Held to maturity, gross unrealized gains	20	77
Held to maturity, gross unrealized losses	0	0
Securities held to maturity, fair value	1,025	1,583
Held to maturity, gross unrealized losses	$ 0	$ 0

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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