Note 12 - Income Taxes - Federal and State Income Tax Expense (Benefit) Summary (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Income tax expense (benefit)	$ 32	$ 3	$ 70	$ (3)
Effective income tax rate	25.00%	(8.00%)	25.00%	4.00%