Segment Information - Schedule of Net PP&E by Geographic Location (Details) - USD ($) $ in Millions	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Net Property, plant and equipment by its geographic location
Net property, plant and equipment	$ 6,693	$ 9,063	$ 9,076
UNITED STATES
Net Property, plant and equipment by its geographic location
Net property, plant and equipment	2,989	4,417	4,582
CANADA
Net Property, plant and equipment by its geographic location
Net property, plant and equipment	260	482	571
North America
Net Property, plant and equipment by its geographic location
Net property, plant and equipment	3,249	4,899	5,153
Latin America
Net Property, plant and equipment by its geographic location
Net property, plant and equipment	716	890	887
Europe/Africa/Russia Caspian
Net Property, plant and equipment by its geographic location
Net property, plant and equipment	1,400	1,805	1,761
Middle East/Asia Pacific
Net Property, plant and equipment by its geographic location
Net property, plant and equipment	$ 1,328	$ 1,469	$ 1,275