Note 11 - Summary of Undiscounted Cash Flows for Next Five Years and Thereafter to Finance Lease Liabilities and Operating Lease Liabilities Recorded on Balance Sheet (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Leases [Abstract]
Operating Leases, 2021	$ 19
Operating Leases, 2022	21
Operating Leases, 2023	11
Operating Leases, 2024	10
Operating Leases, 2025	6
Operating Leases, Thereafter	28
Operating Leases, Total minimum lease payments	95
Operating Leases, Less: amount of lease payments representing interest	(34)
Operating Leases, Present value of future minimum lease payments	61
Operating Leases, Less: current obligations under leases	12	$ 12
Operating Leases, Long-term lease obligations	49	48
Finance Leases, 2021	1
Finance Leases, 2022	1
Finance Leases, 2023	1
Finance Leases, Thereafter	121
Finance Leases, Total minimum lease payments	124
Finance Leases, Less: amount of lease payments representing interest	(120)
Finance Leases, Present value of future minimum lease payments	4
Finance Leases, Less: current obligations under leases	1	1
Finance Leases, Long-term lease obligations	$ 3	$ 4