Note 11 - Retirement Plans - Summary of Funded Status and Amounts Recognized on Balance Sheets (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Projected benefit obligation at beginning of year	$ 104	$ 102
Interest cost	4	5	$ 4
Actuarial (gain) loss	(7)	2
Benefits paid	(5)	(5)
Projected benefit obligation at end of year	96	104	102
Fair value of pension plan assets at beginning of year	117	104
Actual return on plan assets	0	14
Company contributions	0	4
Benefits paid	(5)	(5)
Fair value of pension plan assets at end of year	112	117	$ 104
Funded status of pension plan	16	13
Accrued benefit cost	28	26
Accumulated other comprehensive loss	(12)	(13)
Net asset recognized	$ 16	$ 13