Note 4 - Retirement Plans - Components of Net Periodic Pension and OPEB Cost (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2023	Mar. 31, 2022
Net periodic pension (benefit)/cost	$ (1)	$ 6
Pension Plan [Member]
Service cost	13	26
Interest cost	46	31
Expected return on plan assets	(62)	(73)
Amortization of actuarial loss	$ 2	$ 22