Note 11 - Retirement Plans - Components of Net Periodic Benefit Cost for Pension Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Interest cost	$ 5	$ 4	$ 4
Expected return on plan assets	(7)	(8)	(7)
Recognized net actuarial loss	0	1	1
Net periodic pension benefit	$ (2)	$ (3)	$ (2)