Note 12 - Pension and Postretirement Benefit Plans - Reconciliation of Level 3 Pension Plan Assets (Details) - Pension Plan [Member] - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2020		Dec. 31, 2019
Fair value at beginning of period		$ 802
Fair value at end of period		850		$ 802
UNITED STATES
Fair value at beginning of period		724		1,301
Fair value at end of period		781		724
Foreign Plan [Member]
Fair value at beginning of period		78		71
Fair value at end of period		69		78
Fair Value, Inputs, Level 3 [Member] | UNITED STATES
Fair value at beginning of period		4
Fair value at end of period		6		4
Fair Value, Inputs, Level 3 [Member] | Foreign Plan [Member]
Fair value at beginning of period		46
Fair value at end of period		52		46
Insurance Contracts [Member]
Fair value at beginning of period	[1]	50
Fair value at end of period	[1]	58		50
Insurance Contracts [Member] | Fair Value, Inputs, Level 3 [Member] | UNITED STATES
Fair value at beginning of period		4	[1]	0
Actual gains relating to assets still held at the reporting date		2
Purchases, sales and settlements				4
Fair value at end of period	[1]	6		4
Insurance Contracts [Member] | Fair Value, Inputs, Level 3 [Member] | Foreign Plan [Member]
Fair value at beginning of period		46	[1]	35
Actual gains relating to assets still held at the reporting date		4		7
Purchases, sales and settlements		(2)		5
Currency impact		4		(1)
Fair value at end of period	[1]	$ 52		$ 46

[1] This category comprises contracts placed with insurance companies where the underlying assets are invested in fixed interest securities.