Software Development and Intellectual Property Licenses (Details) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012	Dec. 31, 2012
Software development and intellectual property licenses:
Internally developed software costs	$ 200,000,000		$ 200,000,000		$ 159,000,000
Payments made to third-party software developers	201,000,000		201,000,000		134,000,000
Total software development costs	401,000,000		401,000,000		293,000,000
Intellectual property licenses	12,000,000		12,000,000		41,000,000
Amortization, write-offs and impairments:
Amortization of capitalized software development costs and intellectual property licenses	15,000,000	22,000,000	123,000,000	121,000,000
Write-offs and impairments	$ 0	$ 0	$ 26,000,000	$ 8,000,000