Restructuring and Other Charges - 2017 Actions (Detail) $ in Millions	12 Months Ended
	Dec. 31, 2017 USD ($) employee position	Dec. 31, 2016 USD ($)	Dec. 31, 2015 USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges	$ 165	$ 155	$ 214
Restructuring and other charges after tax	$ 143	114	192
Number of employees associated with layoff costs | position	880
Reversal of forfeited executive stock compensation	$ 13
Severance costs	64	70	97
Other exit costs
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges	69	57
Restructuring and other charges after tax	47	46
Divested Businesses
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges after tax	41
Severance costs	7
Reversal Of Forfeited Executive Stock Compensation
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges	(6)
Restructuring and other charges after tax and noncontrolling interests	4
Other Miscellaneous Charges
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges	12	11	7
Restructuring and other charges after tax		8	4
Restructuring and other charges after tax and noncontrolling interests	7
Other Adjustments
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges	(11)	25	8
Restructuring and other charges after tax		12	3
Restructuring and other charges after tax and noncontrolling interests	$ 8
Restructuring Programs Layoffs Two Thousand Seventeen
Restructuring Cost and Reserve [Line Items]
Number of employees associated with layoff costs | employee	880
Approximate number of employees already laid off | employee	300
Restructuring charges for layoffs	$ 28
Fusina Italy
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges	60
Restructuring and other charges after tax and noncontrolling interests	60
Corporate
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges	$ 11	$ 23	39
Number of employees associated with layoff costs | position	100
Latin America Extrusions (LAE) | Divested Businesses
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges	$ 41
Engineered Products and Solutions
Restructuring Cost and Reserve [Line Items]
Number of employees associated with layoff costs | position	400
Global Rolled Products
Restructuring Cost and Reserve [Line Items]
Number of employees associated with layoff costs | position	245
Global Rolled Products | Divested Businesses
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges			136
Restructuring and other charges after tax			$ 134
Transportation and Construction Solutions
Restructuring Cost and Reserve [Line Items]
Number of employees associated with layoff costs | position	135