Properties, Plants, and Equipment, Net - Schedule of Properties, Plants, and Equipment, Net (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Properties, plants, and equipment, gross	$ 11,365	$ 10,789
Less: accumulated depreciation and amortization	6,392	6,073
Properties, plants, and equipment excluding construction work-in-progress	4,973	4,716
Construction work-in-progress	621	783
Properties, plants, and equipment, net	5,594	5,499
Land and Land Rights
Property, Plant and Equipment [Line Items]
Properties, plants, and equipment, gross	140	135
Structures
Property, Plant and Equipment [Line Items]
Properties, plants, and equipment, gross	2,395	2,296
Machinery and equipment
Property, Plant and Equipment [Line Items]
Properties, plants, and equipment, gross	8,830	8,358
Operating Segments | Engineered Products and Solutions | Structures
Property, Plant and Equipment [Line Items]
Properties, plants, and equipment, gross	784	733
Operating Segments | Engineered Products and Solutions | Machinery and equipment
Property, Plant and Equipment [Line Items]
Properties, plants, and equipment, gross	3,054	2,728
Operating Segments | Global Rolled Products | Structures
Property, Plant and Equipment [Line Items]
Properties, plants, and equipment, gross	1,090	1,061
Operating Segments | Global Rolled Products | Machinery and equipment
Property, Plant and Equipment [Line Items]
Properties, plants, and equipment, gross	4,641	4,570
Operating Segments | Transportation and Construction Solutions | Structures
Property, Plant and Equipment [Line Items]
Properties, plants, and equipment, gross	268	254
Operating Segments | Transportation and Construction Solutions | Machinery and equipment
Property, Plant and Equipment [Line Items]
Properties, plants, and equipment, gross	777	723
Other
Property, Plant and Equipment [Line Items]
Properties, plants, and equipment, net	310	308
Other | Structures
Property, Plant and Equipment [Line Items]
Properties, plants, and equipment, gross	253	248
Other | Machinery and equipment
Property, Plant and Equipment [Line Items]
Properties, plants, and equipment, gross	$ 358	$ 337