Summary Of Assumptions Used To Determine Pension Obligations And Pension Costs (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Maximum [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Percentage	43.00%
Maximum [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Percentage	60.00%
Minimum [Member] | Debt Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Percentage	33.00%
Minimum [Member] | Equity Securities [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Investment within Plan Asset Category, Percentage	40.00%
United States
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	$ 4
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	3.10%	4.15%	3.50%
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	2.25%	3.10%	4.15%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets	7.00%	7.00%	7.00%
Foreign Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Future Employer Contributions, Next Fiscal Year	$ 5
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Discount Rate	1.95%	2.75%	2.55%
Defined Benefit Plan, Assumptions Used Calculating Benefit Obligation, Discount Rate	1.40%	1.95%	2.75%
Defined Benefit Plan, Assumptions Used Calculating Net Periodic Benefit Cost, Expected Long-term Rate of Return on Plan Assets	3.80%	4.50%	4.50%