Restructuring and Other Charges, Net (2021 Actions) - Additional Information (Detail) kt in Thousands, $ in Millions	1 Months Ended	3 Months Ended		12 Months Ended
	Dec. 31, 2021 USD ($) Employees kt	Dec. 31, 2021 USD ($) Employees	Sep. 30, 2021 USD ($)	Dec. 31, 2023 USD ($) Employees	Dec. 31, 2022 USD ($) Employees	Dec. 31, 2021 USD ($) Employees Retiree
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net				$ 184	$ 696	$ 1,128
Number of employees under defined benefit plan | Employees	14,000	14,000		530	4,400	14,000
Lump sum settlements						$ 47
Settlement and curtailment of certain other postretirement benefits				$ (21)	$ (632)	(977)
Cash payments for restructuring				124	39	29
Restart costs				35
Asset impairments				50	58	75
Severance costs				11	1	1
Asset retirement obligation	$ 738	$ 738		989	828	738
Wenatchee (Washington) [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net		80
Cash payments for restructuring				3	1
Charges for write-off remaining net book value of assets		30
Asset impairments		23
Payment of contract termination cost		5
Severance costs		$ 1
Number of employees associated with employee termination and severance costs | Employees		10
Wenatchee (Washington) [Member] | Curtailed Aluminum Smelter Facility [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net						80
Lake Charles (Louisiana) [Member] | Curtailed Aluminum Smelter Facility [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net			$ 27			27
Asset impairments			22
Asset retirement obligation			$ 5
San Ciprian Facility [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net				53
Curtailment of smelting capacity | kt	228
Restricted cash				91
Capital improvement costs				118
Restart costs				35
San Ciprian Facility [Member] | Curtailed Aluminum Smelter Facility [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net		$ 62				62
Cash payments for restructuring				31	26
Capital improvement costs	$ 68
Restart costs	$ 35
Alumar Smelter [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net						6
Aviles and La Coruea Aluminum Facilities [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net						17
Severance and Exit Costs [Member] | Warrick Rolling Mill [Member]
Restructuring Cost and Reserve [Line Items]
Settlement and curtailment of certain other postretirement benefits						9
Additional Contract Costs [Member] | Wenatchee (Washington) and Intalco (Washington) [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net				1	7	13
Additional Environmental and Asset Retirement [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net				17	26	11
Other Item Charges [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net						3
Permanent Close [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net						22
Closure Cost [Member] | Wenatchee (Washington) [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net		90
Decommissioning and Demolition | Wenatchee (Washington) [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net		21
Restructuring and Other Charges [Member] | Warrick Rolling Mill [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net				1
Restructuring and Other Charges [Member] | San Ciprian Facility [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net				53
Cost of Goods Sold [Member] | Warrick Rolling Mill [Member]
Restructuring Cost and Reserve [Line Items]
Charges for write-off remaining net book value of assets				1
Cost of Goods Sold [Member] | Wenatchee (Washington) [Member]
Restructuring Cost and Reserve [Line Items]
Other costs		$ 10
Group Annuity Contract [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net				21	635	$ 858
Number of retirees | Retiree						800
Group Annuity Contract [Member] | Restructuring and Other Charges [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net						$ 63
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
Plan obligations				$ 2,393	$ 2,518
2021 Restructuring Plan Action [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net						1,128
Suriname Pension Plan [Member] | Pension Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges, net						$ 55