Restructuring Charges - Restructuring Roll Forward (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Restructuring Reserve [Roll Forward]
Restructuring Reserve	$ 54	$ 0
Liability recognized	211	129
Payments for Restructuring	(129)	(62)
Other adjustments	(22)	(13)
Restructuring Reserve	114	54
Employee Severance [Member]
Restructuring Reserve [Roll Forward]
Restructuring Reserve	54	0
Liability recognized	177	112
Payments for Restructuring	(116)	(59)
Other adjustments	(2)	1
Restructuring Reserve	113	54
Other Restructuring [Member]
Restructuring Reserve [Roll Forward]
Restructuring Reserve	0	0
Liability recognized	34	17
Payments for Restructuring	(13)	(3)
Other adjustments	(20)	(14)
Restructuring Reserve	$ 1	$ 0