Software Development and Intellectual Property Licenses (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Software development and intellectual property licenses:
Internally developed software costs	$ 152		$ 159
Payments made to third-party software developers	151		134
Total software development costs	303		293
Intellectual property licenses	21		41
Amortization, write-offs and impairments:
Amortization of capitalized software development costs and intellectual property licenses	62	31
Write-offs and impairments	$ 26	$ 2