Note 11 - Leases - Lease Expense (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Amortization of leased assets		$ 1	$ 1	$ 1
Interest on lease liabilities		0	0	0
Operating lease expense		17	19	21
Variable lease expense (1)	[1]	7	9	9
Total lease expense		$ 25	$ 29	$ 31

[1] Variable lease expense is related to real estate leases and primarily includes taxes, insurance and operating costs.