Software Development Costs and Intellectual Property Licenses (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
Software development and intellectual property licenses:
Internally developed software costs	$ 264		$ 264		$ 189
Payments made to third-party software developers	259		259		199
Total software development costs	523		523		388
Intellectual property licenses	2		2		11
Amortization, write-offs and impairments:
Amortization of capitalized software development costs and intellectual property licenses	35	15	143	123
Write-offs and impairments	$ 0	$ 0	$ 0	$ 26