Restructuring and Other Charges, Net (2022 Actions) - Additional Information (Detail) $ in Millions	3 Months Ended	12 Months Ended
	Sep. 30, 2022 USD ($)	Dec. 31, 2023 USD ($) Employees	Dec. 31, 2022 USD ($) Employees	Dec. 31, 2021 USD ($) Employees
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net		$ 184	$ 696	$ 1,128
Number of employees under defined benefit plan | Employees		530	4,400	14,000
Asset impairments		$ 50	$ 58	$ 75
Magnesium Smelter Facility in Addy [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net	$ 29		29
Group Annuity Contract [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net		21	635	858
Pension Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net		$ 235	1,000	1,500
Number of employees under defined benefit plan | Employees		17,000
2022 Restructuring Plans Action [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net			696
Additional Contract Costs [Member] | Wenatchee (Washington) and Intalco (Washington) [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net		$ 1	7	13
Legal Disputes Related to 2019 Divestiture [Member] | Avilés and La Coruña Facilities [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net			79
Asset Impairment [Member] | MRN [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net			58
Additional Environmental and Asset Retirement [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net		17	26	$ 11
Valuation Allowance on Brazil Value-Added Taxes [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net			83
Remediation at Previously Closed Sites [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net		$ 2	$ 34