Segment and Geographic Area Information - Schedule of Segment Reporting Information to Consolidated Assets (Detail) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Schedule Of Assets By Segment [Line Items]
Consolidated assets	$ 17,447	$ 16,741
Cash and cash equivalents	1,358	853	$ 557	$ 266
LIFO reserve	(306)	(215)
Corporate fixed assets, net	9,138	9,325
Corporate goodwill	989	989
Deferred income taxes	517
Operating Segments [Member]
Schedule Of Assets By Segment [Line Items]
Consolidated assets	14,798	13,990
Intersegment Eliminations [Member]
Schedule Of Assets By Segment [Line Items]
Consolidated assets	(299)	(236)
Other [Member]
Schedule Of Assets By Segment [Line Items]
Cash and cash equivalents	1,358	853
LIFO reserve	(306)	(215)
Corporate fixed assets, net	520	595
Corporate goodwill	148	149
Deferred income taxes	814	741
Fair value of derivative contracts	34	497
Other	$ 380	$ 367