Retirement Plans - Amounts Recognized in Balance Sheet for Pension Plans & Postretirement Medical Plan (Detail) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Noncurrent assets	$ 409	$ 45
Accumulated other comprehensive (gain) loss related to retirement plans, after-tax - Deficit	338	759
Funded Pension Plans
Defined Benefit Plan Disclosure [Line Items]
Noncurrent assets	409	45
Current liabilities	0	0
Noncurrent liabilities	0	(87)
Pension assets / (accrued benefit liability)	409	(42)
Accumulated other comprehensive loss, pre-tax	501	900
Unfunded Pension Plan
Defined Benefit Plan Disclosure [Line Items]
Noncurrent assets	0	0
Current liabilities	(34)	(49)
Noncurrent liabilities	(214)	(220)
Pension assets / (accrued benefit liability)	(248)	(269)
Accumulated other comprehensive loss, pre-tax	66	86
Postretirement Medical Plan
Defined Benefit Plan Disclosure [Line Items]
Noncurrent assets	0	0
Current liabilities	(6)	(7)
Noncurrent liabilities	(53)	(58)
Pension assets / (accrued benefit liability)	(59)	(65)
Accumulated other comprehensive loss, pre-tax	$ (21)	$ (19)