Software Development and Intellectual Property Licenses (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012	Dec. 31, 2012
Software development and intellectual property licenses:
Internally developed software costs	$ 167,000,000		$ 167,000,000		$ 159,000,000
Payments made to third-party software developers	172,000,000		172,000,000		134,000,000
Total software development costs	339,000,000		339,000,000		293,000,000
Intellectual property licenses	11,000,000		11,000,000		41,000,000
Amortization, write-offs and impairments:
Amortization of capitalized software development costs and intellectual property licenses	46,000,000	68,000,000	108,000,000	99,000,000
Write-offs and impairments	$ 0	$ 6,000,000	$ 26,000,000	$ 8,000,000