Employee Benefits - Recorded Severance Liability (Detail) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Movements in Severance Benefits [Roll Forward]
Beginning of Year	$ 602	$ 565	$ 2,156
Charged to Expense	233	309	260
Payments	(258)	(248)	(1,847)
Other	(29)	(24)	(4)
End of Year	$ 548	$ 602	$ 565