Income Tax - Difference Between Effective Tax Rate (Detail) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Income Tax Disclosure [Abstract]
Federal income tax at the U.S. federal statutory rate	$ 15	$ 19	$ 37	$ 40
Foreign income tax rate differential	(1)		(3)	(2)
State income tax, net of federal benefit	1		1
Nondeductible expenses	1		3	2
Foreign tax credit	(1)		(2)
Other	1	3	1	1
Provision for income taxes	$ 16	$ 22	$ 37	$ 41