Schedule of Marketable Securities (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Schedule of Available-for-sale Securities [Line Items]
Cost	$ 109	$ 59
Unrealized Gains	1	1
Fair Value	110	60
U.S. government and agencies
Schedule of Available-for-sale Securities [Line Items]
Cost	27	7
Unrealized Gains	0	0
Fair Value	27	7
Corporate Securities
Schedule of Available-for-sale Securities [Line Items]
Cost	30	11
Unrealized Gains	(1)
Fair Value	29	11
Certificates of deposit
Schedule of Available-for-sale Securities [Line Items]
Cost	21	16
Unrealized Gains
Fair Value	21	16
Other
Schedule of Available-for-sale Securities [Line Items]
Cost	31	25
Unrealized Gains	2	1
Fair Value	$ 33	$ 26