Note 3 - Securities (Tables)

9 Months Ended

Sep. 30, 2025

Notes Tables

Schedule of Available-for-Sale Securities Reconciliation [Table Text Block]

		*Amortized Cost*				*Gross Unrealized Gains*				*Gross Unrealized Losses*				*Fair Value*
Available-for-Sale Securities
September 30, 2025
Municipal securities		$	702			$	5			$	—			$	707
U.S. Treasury Bills and Notes			533,241				214				(101	)			533,354
Mortgage-backed securities - residential			2,692				37				(48	)			2,681
Collateralized mortgage obligations - residential			770				—				(9	)			761
		$	537,405			$	256			$	(158	)		$	537,503
December 31, 2024
Municipal securities		$	703			$	3			$	—			$	706
U.S. Treasury Bills and Notes			246,876				103				(689	)			246,290
U.S. government-sponsored agencies			109,900				1				(128	)			109,773
Mortgage-backed securities - residential			2,949				31				(69	)			2,911
Collateralized mortgage obligations - residential			862				—				(12	)			850
		$	361,290			$	138			$	(898	)		$	360,530

Investments Classified by Contractual Maturity Date [Table Text Block]

		*September 30, 2025*
		*Amortized Cost*				*Fair Value*
Due in one year or less		$	520,347			$	520,479
Due after one year through five years			13,596				13,582
			533,943				534,061
Mortgage-backed securities - residential			2,692				2,681
Collateralized mortgage obligations - residential			770				761
		$	537,405			$	537,503

Debt Securities, Available-for-Sale, Unrealized Loss Position, Fair Value [Table Text Block]

		*Less than 12 Months*												*12 Months or More*												*Total*
		*Count*				*Fair Value*				*Unrealized Loss*				*Count*				*Fair Value*				*Unrealized Loss*				*Count*				*Fair Value*				*Unrealized Loss*
September 30, 2025
U.S. Treasury Bills and Notes			—			$	—			$	—				16			$	5,884			$	(101	)			16			$	5,884			$	(101	)
Mortgage-backed securities - residential			—				—				—				5				1,141				(48	)			5				1,141				(48	)
Collateralized mortgage obligations - residential			—				—				—				5				761				(9	)			5				761				(9	)
			—			$	—			$	—				26			$	7,786			$	(158	)			26			$	7,786			$	(158	)

December 31, 2024
U.S. Treasury Bills and Notes			—			$	—			$	—				73			$	48,609			$	(689	)			73			$	48,609			$	(689	)
U.S. government-sponsored agencies			10				79,872				(128	)			—				—				—				10				79,872				(128	)
Mortgage-backed securities - residential			—				—				—				7				1,364				(69	)			7				1,364				(69	)
Collateralized mortgage obligations - residential			—				—				—				5				850				(12	)			5				850				(12	)
			10			$	79,872			$	(128	)			85			$	50,823			$	(770	)			95			$	130,695			$	(898	)