Property and Equipment, Net - Summary of Property and Equipment (Detail) (USD $) In Millions, unless otherwise specified	Dec. 31, 2013	Dec. 31, 2012
Property, Plant and Equipment [Line Items]
Cost	$ 1,024	$ 947
Accumulated depreciation	(596)	(531)
Net	428	416
Capitalized software [Member]
Property, Plant and Equipment [Line Items]
Cost	650	629
Accumulated depreciation	(449)	(386)
Net	201	243
Computer equipment [Member]
Property, Plant and Equipment [Line Items]
Cost	281	274
Accumulated depreciation	(139)	(138)
Net	142	136
Building and leasehold improvements [Member]
Property, Plant and Equipment [Line Items]
Cost	17	12
Accumulated depreciation	(8)	(7)
Net	9	5
Construction in progress [Member]
Property, Plant and Equipment [Line Items]
Cost	76	32
Accumulated depreciation
Net	$ 76	$ 32