Restructuring and Other Charges, Net (2022 Actions) - Additional Information (Detail) $ in Millions	3 Months Ended	12 Months Ended
	Sep. 30, 2022 USD ($)	Dec. 31, 2022 USD ($) Employee	Dec. 31, 2021 USD ($) Employee	Dec. 31, 2020 USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net (D)		$ 696	$ 1,128	$ 104
Number of employees under defined benefit plan | Employee		4,400	14,000
Asset impairments		$ 58	$ 75	$ 2
Magnesium Smelter Facility in Addy [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net (D)	$ 29	29
MRN [Member]
Restructuring Cost and Reserve [Line Items]
Asset impairments		58
Group Annuity Contract [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net (D)		635	858
Pension Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net (D)		$ 1,000	1,500
Number of employees under defined benefit plan | Employee		22,000
2022 Restructuring Plans Action [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net (D)		$ 696
Additional Contract Costs [Member] | Wenatchee (Washington) and Intalco (Washington) [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net (D)		(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 (D)		79
Additional Environmental and Asset Retirement [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net (D)		26	$ 11
Valuation Allowance on Brazil Value-Added Taxes [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net (D)		83
Remediation at Previously Closed Sites [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net (D)		$ 34