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]
Construction in process	$ 379	$ 494
Property, plant and equipment	15,230	15,477
Pipeline Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	7,631	7,462
Offshore Drilling Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	5,693	6,071
Other [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment	$ 1,527	$ 1,450