Note 12 - Pension and Postretirement Benefit Plans (Details Textual) $ in Millions	1 Months Ended	3 Months Ended	12 Months Ended
	Jun. 30, 2019 USD ($)	Jun. 30, 2019 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2018 USD ($)	Oct. 31, 2017
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement		$ (258)		$ (259)
Period of Forecast (Year)			10 years
Minimum [Member]
Multiemployer Plans, Green Zone, Percentage			80.00%
Multiemployer Plans, Yellow Zone, Percentage			65.00%
Multi-employer Plan, Employer Contribution, Percentage			5.00%
Maximum [Member]
Multiemployer Plans, Red Zone, Percentage			65.00%
UNITED STATES | Pension Plan [Member]
Defined Benefit Plan, Expected Amortization, Next Fiscal Year, Total			$ 9
Defined Benefit Plan, Plan Assets, Contributions by Employer			1	59
Defined Benefit Plan, Funded (Unfunded) Status of Plan, Total			(29)	(48)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement				(256)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, before Tax			$ 4	$ 107	$ (11)
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate			2.43%	3.21%	4.22%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Return on Assets, Next Fiscal Year			3.50%
UNITED STATES | Pension Plan [Member] | Growth Portfolio [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage			20.00%
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage			21.00%
UNITED STATES | Pension Plan [Member] | Immunizing Portfolio [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage			78.00%
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage			76.00%
UNITED STATES | Pension Plan [Member] | Liquidity Portfolio [Member]
Defined Benefit Plan, Plan Assets, Target Allocation, Percentage			2.00%
Defined Benefit Plan, Plan Assets, Actual Allocation, Percentage			3.00%
UNITED STATES | Pension Plan [Member] | Terminated Plan [Member]
Number of Plans Terminated						1
Defined Benefit Plan, Plan Assets, Contributions by Employer	$ 59
Defined Benefit Plan, Funded (Unfunded) Status of Plan, Total	$ 165	$ 165
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement				$ 256
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate					3.46%
Foreign Plan [Member] | Pension Plan [Member]
Defined Benefit Plan, Expected Amortization, Next Fiscal Year, Total			$ 9
Defined Benefit Plan, Plan Assets, Contributions by Employer			14	17
Defined Benefit Plan, Funded (Unfunded) Status of Plan, Total			(369)	(334)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Gain (Loss) Due to Settlement				(3)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, before Tax			$ (10)	$ (33)	$ (4)
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate			1.40%	1.72%	2.42%
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year			$ 16