Segment and Geographic Area Information - Schedule of Geographic Information for Long-Lived Assets (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 17,639	$ 18,947
U.S. [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	4,760	4,621
Brazil [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	3,746	4,318
Australia [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	3,024	3,548
Iceland [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	1,518	1,571
Canada [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	1,302	1,399
Norway [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	762	898
Russia [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	471	494
Spain [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	446	445
Jamaica [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	393	414
China [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	388	395
Other Geographical Regions [Member]
Revenues from External Customers and Long-Lived Assets [Line Items]
Long-lived assets	$ 829	$ 844