Note 5 - Fair Value of Financial Instruments - Estimated Carrying Amounts and Fair Values (Details) - USD ($) $ in Millions		Sep. 30, 2019	Dec. 31, 2018
Reported Value Measurement [Member]
Long-term debt, including current portion (a)	[1]	$ 6,179	$ 6,043
Estimate of Fair Value Measurement [Member]
Long-term debt, including current portion (a)	[1]	$ 6,173	$ 5,943

[1] Excludes net debt issuance costs, which are recorded as a reduction to long-term debt on the Company's consolidated balance sheets.