Property, Plant and Equipment - Components of Property, Plant and Equipment (Detail) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014
Property, Plant and Equipment [Line Items]
Construction in process	$ 494	$ 578
Property, plant and equipment, net	15,477	15,611
Pipeline Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	7,462	7,491
Offshore Drilling Equipment [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	6,071	6,459
Other [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, net	$ 1,450	$ 1,083