Software Development Costs and Intellectual Property Licenses (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014	Dec. 31, 2014
Software development and intellectual property licenses:
Internally-developed software costs	$ 259		$ 259		$ 262
Payments made to third-party software developers	159		159		210
Total software development costs	418		418		472
Intellectual property licenses	26		26		$ 23
Amortization:
Amortization of capitalized software development costs and intellectual property licenses	$ 85	$ 50	$ 232	$ 108