Software Development and Intellectual Property Licenses (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Software development and intellectual property licenses:
Internally-developed software costs	$ 277	$ 266
Payments made to third-party software developers	189	150
Total software development costs	466	416
Intellectual property licenses	2	30
Amortization, write-offs and impairments:
Amortization of capitalized software development costs and intellectual property licenses	$ 335	$ 410	$ 272