Goodwill (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Goodwill [Roll Forward]
Balance at beginning of period	$ 1,244	$ 1,240	$ 1,108
Acquisition	0	6	132
Foreign currency translation	(55)	(2)	0
Balance at end of period	1,189	1,244	1,240
North America [Member]
Goodwill [Roll Forward]
Balance at beginning of period	1,106	1,108	1,108
Acquisition	0	0	0
Foreign currency translation	(1)	(2)	0
Balance at end of period	1,105	1,106	1,108
International [Member]
Goodwill [Roll Forward]
Balance at beginning of period	138	132	0
Acquisition	0	6	132
Foreign currency translation	(54)	0	0
Balance at end of period	$ 84	$ 138	$ 132