Note 8 - Income Taxes - Reconciliation of Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Balance at January 1	$ 131	$ 62	$ 435
Additions based on tax positions related to the current year	54	19	3
Additions for tax positions of prior years	17	53	2
Reductions for tax positions of prior years	(21)
Settlements and lapse of statute of limitations	(3)	(3)	(378)
Balance at December 31	$ 178	$ 131	$ 62