Restructuring and Other Charges - 2013 Actions - Additional Information (Detail) € in Millions	1 Months Ended		3 Months Ended	12 Months Ended
	Aug. 31, 2013 Potline t	May. 31, 2013 Potline t	Dec. 31, 2015 USD ($)	Dec. 31, 2015 EUR (€) t	Dec. 31, 2015 USD ($) t	Dec. 31, 2014 USD ($) Employees	Dec. 31, 2013 USD ($) Employees
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges			$ 735,000,000	€ 150	$ 1,195,000,000	$ 1,168,000,000	$ 782,000,000
Restructuring and other charges, after-tax and noncontrolling interest			$ 507,000,000		$ 836,000,000	$ 703,000,000	$ 585,000,000
Number of employees associated with layoff costs | Employees						1,120	1,110
Reduction in production - result of market conditions, in metric tons per year | t		460,000		2,800,000	2,800,000
Capacity of lines under review period		15 months		12 months	12 months
Accelerated depreciation							$ 58,000,000
Other asset impairment charges					$ 335,000,000	$ 406,000,000	$ 116,000,000
Inventory write-down - permanent shutdown and planned demolition of idled structures					90,000,000
Inventory write-down, after-tax and non-controlling interests					43,000,000
Minimum amount of cash payments expected to be paid beyond the end of the current annual period					10,000,000
Maximum amount of cash payments expected to be paid beyond the end of the current annual period					15,000,000
Primary Metals [Member]
Restructuring Cost and Reserve [Line Items]
Number of employees associated with layoff costs | Employees							340
Transportation and Construction Solutions [Member]
Restructuring Cost and Reserve [Line Items]
Number of employees associated with layoff costs | Employees							75
Engineered Products and Solutions [Member]
Restructuring Cost and Reserve [Line Items]
Number of employees associated with layoff costs | Employees						470	220
Global Rolled Products [Member]
Restructuring Cost and Reserve [Line Items]
Number of employees associated with layoff costs | Employees						45	250
Alumina [Member]
Restructuring Cost and Reserve [Line Items]
Number of employees associated with layoff costs | Employees							85
Corporate [Member]
Restructuring Cost and Reserve [Line Items]
Number of employees associated with layoff costs | Employees						185	140
Global Rolled Products Segment [Member]
Restructuring Cost and Reserve [Line Items]
Number of employees associated with layoff costs | Employees							590
Retirement Of Previously Idled Structure [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges							$ 25,000,000
Restructuring and other charges, after-tax and noncontrolling interest							17,000,000
Write Off Of Capitalized Structure [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges							13,000,000
Restructuring and other charges, after-tax and noncontrolling interest							25,000,000
Fusina and Massena East [Member]
Restructuring Cost and Reserve [Line Items]
Other asset impairment charges							18,000,000
Baie Comeau Smelter [Member]
Restructuring Cost and Reserve [Line Items]
Number of potlines to be shutdown and demolished | Potline	1	2
Reduction in production - result of market conditions, in mt per year | t		105,000
Quebec Canada [Member]
Restructuring Cost and Reserve [Line Items]
Reduction in production - result of market conditions, in mt per year | t	41,000
Reduction in production - result of market conditions, in mt per year | t		280,000
Fusina Italy [Member]
Restructuring Cost and Reserve [Line Items]
Reduction in production - result of market conditions, in mt per year | t		44,000
Reduction in production - result of market conditions, in metric tons per year | t	84,000
Exit Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges							$ 114,000,000
Exit Costs [Member] | Primary Metals [Member]
Restructuring Cost and Reserve [Line Items]
Number of employees associated with layoff costs | Employees							550
Permanent Shutdown and Planned Demolition of Idled Structures [Member]
Restructuring Cost and Reserve [Line Items]
Other exit costs							$ 55,000,000
Operating Supplies [Member]
Restructuring Cost and Reserve [Line Items]
Inventory write-down - permanent shutdown and planned demolition of idled structures							9,000,000
Inventory write-down, after-tax and non-controlling interests							6,000,000
Asset Retirement Obligations [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges					76,000,000	$ 95,000,000	58,000,000
Other exit costs						95,000,000	48,000,000
Environmental Remediation [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges					86,000,000	47,000,000	12,000,000
Other exit costs						42,000,000	5,000,000
Supplier and Customer Contract [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges					65,000,000
Other exit costs						46,000,000	2,000,000
Restructuring Programs Layoffs 2013 [Member]
Restructuring Cost and Reserve [Line Items]
Cash payments made against the layoff reserves					7,000,000	39,000,000	33,000,000
Legal Matter [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges							391,000,000
Restructuring and other charges, after-tax and noncontrolling interest							305,000,000
Other Exit Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges					438,000,000	693,000,000	245,000,000
Restructuring and other charges, after-tax and noncontrolling interest					281,000,000	443,000,000	183,000,000
Layoff Costs [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges					156,000,000	51,000,000	87,000,000
Restructuring and other charges, after-tax and noncontrolling interest						36,000,000	61,000,000
Pension Benefits [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges							9,000,000
Asset Impairments and Retirements Costs [Member] | Retirement Of Previously Idled Structure [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges							12,000,000
Restructuring and other charges, after-tax and noncontrolling interest							8,000,000
Other Miscellaneous Items [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges					4,000,000	18,000,000	17,000,000
Restructuring and other charges, after-tax and noncontrolling interest					$ 7,000,000	11,000,000	12,000,000
Small Layoff Reserves Related to Prior Periods [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges						28,000,000
Restructuring and other charges, after-tax and noncontrolling interest						21,000,000
Restructuring reserve, other adjustment							8,000,000
Restructuring reserve, other adjustment, after-tax							6,000,000
Asset Impairment [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges						34,000,000	3,000,000
Restructuring and other charges, after-tax and noncontrolling interest						$ 26,000,000	$ 2,000,000