Restructuring and Other Charges - 2015 Actions - Additional Information (Detail) $ in Millions	3 Months Ended	12 Months Ended
	Dec. 31, 2015 USD ($)	Dec. 31, 2016 USD ($) Employees	Dec. 31, 2015 USD ($) Employees Divestiture	Dec. 31, 2014 USD ($) Divestiture
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges	$ 685	$ 155	$ 214	$ 314
Restructuring and other charges after tax and noncontrolling interest		114	$ 192	249
Number of plant divestitures | Divestiture			3
Corporate [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges		23	$ 39	24
Shutdown and Curtailment Actions [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges		37
Restructuring and other charges after tax and noncontrolling interest		24
Shutdown and Curtailment Actions [Member] | Australia [Member]
Restructuring Cost and Reserve [Line Items]
Gain on sale of land			18
Gain on sale of land after tax			13
Divested Businesses [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges				111
Restructuring and other charges after tax and noncontrolling interest				$ 112
Number of plant divestitures | Divestiture				3
Divested Businesses [Member] | Global Rolled Products [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges			136
Restructuring and other charges after tax and noncontrolling interest			134
Other Miscellaneous Items [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges		11	7	$ 10
Restructuring and other charges after tax and noncontrolling interest		8	4	7
Other Adjustments [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges		25	8	10
Restructuring and other charges after tax and noncontrolling interest		12	3	5
Restructuring Programs Layoffs 2014 [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges				49
Restructuring and other charges after tax and noncontrolling interest				28
Adjustments associated with divestitures			97
Adjustment associated with divestitures after tax			$ 70
Number of positions | Employees			1,505
Restructuring charges for layoffs		3	$ 27	$ 54
Restructuring Programs Layoffs 2014 [Member] | Corporate [Member]
Restructuring Cost and Reserve [Line Items]
Number of positions | Employees			400
Restructuring Programs Layoffs 2014 [Member] | Global Rolled Products [Member]
Restructuring Cost and Reserve [Line Items]
Number of positions | Employees			90
Restructuring Programs Layoffs 2014 [Member] | Transportation and Construction Solutions [Member]
Restructuring Cost and Reserve [Line Items]
Number of positions | Employees			425
Restructuring Programs Layoffs 2014 [Member] | Engineered Products and Solutions [Member]
Restructuring Cost and Reserve [Line Items]
Number of positions | Employees			590
Restructuring Programs Layoffs 2015 [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring and other charges		53
Restructuring and other charges after tax and noncontrolling interest		$ 33
Number of positions | Employees		1,100
Number of employees | Employees		1,240	1,505
Restructuring charges for layoffs		$ 55	$ 18