Employee Benefit Plans (Additional Information) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Pension and Other Postretirement Benefits Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Increase (Decrease) for Assets Transferred to (from) Plan			$ 20
Contributions to defined benefit pension plans			75
Pension settlement charge		$ 0	0	$ 60
ABO for all defined benefit pension plans		$ 3,400	$ 2,900
Return on plan assets assumption		5.40%	5.40%	5.40%
Impact on net periodic pension expense		$ 13
Weighted-average healthcare cost trend rate assumed for next fiscal year		5.00%
Assumed ultimate health care cost trend rate		4.30%
Aggregate PBO for the pension plans with PBO in excess of plan assets		$ 2,223	$ 1,935
Aggregate fair value of plan assets for the pension plans with PBO in excess of plan assets		1,449	1,269
Aggregate ABO for the pension plans with ABO in excess of plan assets		2,176	1,883
Fair value of plan assets for the pension plans with ABO in excess of plan assets		1,449	1,269
Scenario, Forecast
Pension and Other Postretirement Benefits Disclosure [Line Items]
Weighted-average healthcare cost trend rate assumed for next fiscal year	4.80%
Assumed ultimate health care cost trend rate	4.30%
Pension Plan [Member]
Pension and Other Postretirement Benefits Disclosure [Line Items]
Contributions to defined benefit pension plans		13	99
Defined Benefit Plan, Benefit Obligation, Benefits Paid		144	125
Net actuarial loss arising during the year		179
Estimated future benefit payments in 2020		145
Estimated future benefit payments in 2021		143
Estimated future benefit payments in 2022		146
Estimated future benefit payments in 2023		153
Estimated future benefit payments in 2024		160
Estimated aggregate future benefits payments for the five years thereafter		845
Pension Plan [Member] | Scenario, Forecast
Pension and Other Postretirement Benefits Disclosure [Line Items]
Impact on net periodic pension expense	$ 16
Postretirement Health Coverage
Pension and Other Postretirement Benefits Disclosure [Line Items]
Plan amendments				$ (306)
Amortization reduction period				5 years 7 months 6 days
Other Postretirement Benefits
Pension and Other Postretirement Benefits Disclosure [Line Items]
Plan amendments		(17)	0
Defined Benefit Plan, Benefit Obligation, Benefits Paid		49	49
Net actuarial loss arising during the year		60
Estimated future benefit payments in 2020		51
Estimated future benefit payments in 2021		51
Estimated future benefit payments in 2022		50
Estimated future benefit payments in 2023		49
Estimated future benefit payments in 2024		48
Estimated aggregate future benefits payments for the five years thereafter		$ 209
Other Postretirement Benefits | Scenario, Forecast
Pension and Other Postretirement Benefits Disclosure [Line Items]
Impact on net periodic pension expense	$ 6
Welfare Benefits - U.S.
Pension and Other Postretirement Benefits Disclosure [Line Items]
Percentage of defined benefit pension plan assets market value		87.00%
U.S. Qualified Pension Plan
Pension and Other Postretirement Benefits Disclosure [Line Items]
Defined Benefit Plan, Benefit Obligation, Benefits Paid				$ 87
Pension settlement charge				35
U.S. Non-qualified Plan
Pension and Other Postretirement Benefits Disclosure [Line Items]
Defined Benefit Plan, Benefit Obligation, Benefits Paid				40
Pension settlement charge				22
United States, Canada, Netherlands and United Kingdom
Pension and Other Postretirement Benefits Disclosure [Line Items]
Percentage of defined benefit pension plan assets market value		93.00%
United States
Pension and Other Postretirement Benefits Disclosure [Line Items]
Contributions to defined benefit pension plans		$ 0	75	54
Return on plan assets assumption		7.40%
United States | Scenario, Forecast
Pension and Other Postretirement Benefits Disclosure [Line Items]
Return on plan assets assumption	7.40%
United States | Pension Plan [Member]
Pension and Other Postretirement Benefits Disclosure [Line Items]
Contributions to defined benefit pension plans		$ 0	75
Defined Benefit Plan, Benefit Obligation, Benefits Paid		80	70
United States | Other Postretirement Benefits
Pension and Other Postretirement Benefits Disclosure [Line Items]
Plan amendments		(17)	0
Defined Benefit Plan, Benefit Obligation, Benefits Paid		44	45
International
Pension and Other Postretirement Benefits Disclosure [Line Items]
Contributions to defined benefit pension plans		13	24	$ 33
Estimated future mandatory contributions, low end of range		15
Estimated future mandatory contributions, high end of range		20
International | Scenario, Forecast
Pension and Other Postretirement Benefits Disclosure [Line Items]
Return on plan assets assumption	5.00%
International | Pension Plan [Member]
Pension and Other Postretirement Benefits Disclosure [Line Items]
Contributions to defined benefit pension plans		13	24
Defined Benefit Plan, Benefit Obligation, Benefits Paid		64	55
International | Other Postretirement Benefits
Pension and Other Postretirement Benefits Disclosure [Line Items]
Plan amendments		0	0
Defined Benefit Plan, Benefit Obligation, Benefits Paid		$ 5	$ 4