Note 11 - Income Taxes - Federal and State Income Tax Expense (Benefit) Summary (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Income tax expense (benefit)	$ 7	$ 5	$ 38	$ (6)
Effective income tax rate	24.00%	56.00%	26.00%	18.00%