Restructuring and Other Charges - 2017 Actions (Details) $ in Millions	12 Months Ended
	Dec. 31, 2018 USD ($) position	Dec. 31, 2017 USD ($) position	Dec. 31, 2016 USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges	$ 9	$ 165	$ 155
Restructuring and other charges after tax	9	$ 143	114
Number of employees associated with layoff costs | position		880
Reversal of forfeited executive stock compensation		$ 13
Severance costs	20	64	68
Cash payments for restructuring	49	65	86
Other Exit Costs
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges	19	69	57
Restructuring and other charges after tax	15	47	46
Cash payments for restructuring	2	6	13
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
Restructuring and other charges after tax			8
Restructuring and other charges after tax and noncontrolling interests		7
Other Adjustments
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges	8	(11)	25
Restructuring and other charges after tax			$ 12
Restructuring and other charges after tax and noncontrolling interests	$ 4	$ (8)
Restructuring Programs Layoffs Two Thousand Seventeen
Restructuring Cost and Reserve [Line Items]
Number of employees associated with layoff costs | position	660	760
Approximate number of employees already laid off | position	570
Cash payments for restructuring	$ 34
Fusina Italy
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges		$ 60
Restructuring and other charges after tax and noncontrolling interests		60
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
Transportation and Construction Solutions
Restructuring Cost and Reserve [Line Items]
Number of employees associated with layoff costs | position		135
Corporate Segment
Restructuring Cost and Reserve [Line Items]
Number of employees associated with layoff costs | position		100