Restructuring and Other Charges - Additional Information (Detail)		3 Months Ended			9 Months Ended		12 Months Ended
	Sep. 30, 2017 Employees	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($) Employees Positions	Sep. 30, 2016 USD ($) Positions	Sep. 30, 2017 USD ($) Employees Positions	Sep. 30, 2016 USD ($) Positions	Dec. 31, 2016 USD ($) Employees
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges			$ 19,000,000	$ 3,000,000	$ 118,000,000	$ 33,000,000
Restructuring and other charges after tax and noncontrolling interest			$ 13,000,000	$ 2,000,000	$ 99,000,000	$ 22,000,000
Number of employees associated with layoff costs | Positions			124	70	800	1,140
Reversal of forfeited executive stock compensation					$ 13,000,000
Severance charges					7,000,000
Cash payments made against the layoff reserves					46,000,000		$ 86,000,000
Minimum amount of cash payments expected to be paid beyond the end of the current annual period					15,000,000
Maximum amount of cash payments expected to be paid beyond the end of the current annual period					20,000,000
Corporate [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges			$ 5,000,000	$ 7,000,000	$ 7,000,000	$ 10,000,000
Number of employees associated with layoff costs | Positions			12	10	74	10
Engineered Products and Solutions [Member]
Restructuring Cost and Reserve [Line Items]
Number of employees associated with layoff costs | Positions			111	60	350	860
Global Rolled Products [Member]
Restructuring Cost and Reserve [Line Items]
Number of employees associated with layoff costs | Positions			1		243	30
Transportation and Construction Solutions [Member]
Restructuring Cost and Reserve [Line Items]
Number of employees associated with layoff costs | Positions					133	240
Brazil [Member] | Transportation and Construction Solutions [Member] | Extrusions Business [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges					$ 0	$ 0	$ 0
Brazil [Member] | Transportation and Construction Solutions [Member] | Scenario, Forecast [Member] | Extrusions Business [Member] | Minimum [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges		$ 30,000,000
Brazil [Member] | Transportation and Construction Solutions [Member] | Scenario, Forecast [Member] | Extrusions Business [Member] | Maximum [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges		$ 50,000,000
Fusina Italy [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges					60,000,000
Restructuring and other charges after tax and noncontrolling interest					60,000,000
Restructuring Programs Layoffs 2015 [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges			$ 11,000,000	$ 4,000,000	59,000,000	34,000,000
Restructuring and other charges after tax and noncontrolling interest			$ 8,000,000	2,000,000	$ 40,000,000	21,000,000
Number of employees associated with layoff costs | Employees					1,220		1,240
Approximate number of employees already laid off | Employees	1,120		1,120		1,120
Cash payments made against the layoff reserves			$ 1,000,000		$ 5,000,000
Other Miscellaneous Items [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges			8,000,000	7,000,000	7,000,000	14,000,000
Restructuring and other charges after tax and noncontrolling interest			$ 5,000,000	5,000,000	5,000,000	9,000,000
Other Adjustments [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges				8,000,000	2,000,000	15,000,000
Restructuring and other charges after tax and noncontrolling interest				$ 5,000,000	$ 2,000,000	$ 8,000,000
Restructuring Programs Layoffs 2017 [Member]
Restructuring Cost and Reserve [Line Items]
Number of employees associated with layoff costs | Employees	800
Approximate number of employees already laid off | Employees	155		155		155
Cash payments made against the layoff reserves			$ 13,000,000		$ 11,000,000
Restructuring Programs Layoffs 2016 [Member]
Restructuring Cost and Reserve [Line Items]
Number of employees associated with layoff costs | Employees	1,750						1,800
Approximate number of employees already laid off | Employees	1,200		1,200		1,200
Cash payments made against the layoff reserves			$ 3,000,000		$ 23,000,000
Reversal of Forfeited Executive Stock Compensation [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges					6,000,000
Restructuring and other charges after tax and noncontrolling interest					$ 4,000,000