Note 10 - Income Taxes - Federal and State Income Tax Expense (Benefit) Summary (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Federal	$ 39	$ 8	$ 43
State and local	20	13	11
Current income tax expense	59	21	54
Federal	64	54	17
State and local	11	1	6
Deferred income tax expense	75	55	23
Income tax expense as recorded	$ 134	$ 76	$ 77