Note 9 - Leases - Lease Expense (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Operating lease expense	$ 3	$ 3	$ 9	$ 9
Short-term lease expense	1	0	2	1
Total lease expense	$ 4	$ 3	$ 11	$ 10