Segment Information - Financial Information by Major Geographic Area (Parenthetical) (Detail) - USD ($) $ in Millions		Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Property, plant and equipment, net	[1]	$ 23,595	$ 26,352
Norway
Segment Reporting Information [Line Items]
Property, plant and equipment, net		$ 3,893	$ 4,108

[1] Of the total Europe, Property, plant and equipment (net), Norway represented $3,893 million in 2016 (2015: $4,108 million).