Property, Plant and Equipment - Components of Property, Plant and Equipment (Detail) - USD ($) $ in Millions		Dec. 31, 2016	Dec. 31, 2015
Property Plant And Equipment [Line Items]
Total — at cost		$ 46,907	$ 46,826
Less: Reserves for depreciation, depletion, amortization and lease impairment		23,312	20,474
Property, Plant and Equipment — Net	[1]	23,595	26,352
Exploration and Production
Property Plant And Equipment [Line Items]
Unproved properties		710	958
Proved properties		4,258	4,202
Wells, equipment and related facilities		38,821	38,738
Total — at cost		43,789	43,898
Bakken Midstream
Property Plant And Equipment [Line Items]
Total — at cost		3,018	2,757
Corporate and Other
Property Plant And Equipment [Line Items]
Total — at cost		$ 100	$ 171

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