Employee Benefit Plans (Change in Fair Value of Company's Level 3 Pension Assets) (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	$ 3,216
End balance	2,975	$ 3,216
Level 3
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	916	835
Realized gains	1	30
Unrealized losses	30	(7)
Transfers in/(out), net	38	15
Foreign currency gains	(31)	43
End balance	954	916
Level 3 | Real Estate
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	124	123
Realized gains	3	4
Unrealized losses	22	(5)
Transfers in/(out), net	8	1
Foreign currency gains	0	1
End balance	157	124
Level 3 | Other Debt Securities
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	421	377
Realized gains	(11)	24
Unrealized losses	0	0
Transfers in/(out), net	(14)	(14)
Foreign currency gains	(29)	34
End balance	367	421
Level 3 | Hedge Funds and Other Assets
Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward]
Beginning balance	371	335
Realized gains	9	2
Unrealized losses	8	(2)
Transfers in/(out), net	44	28
Foreign currency gains	(2)	8
End balance	$ 430	$ 371