Restructuring Charges/Other - Restructuring Reserve (Details) - USD ($) $ in Millions		3 Months Ended		9 Months Ended
		Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015		Sep. 30, 2014
Restructuring Reserve
Accrual, beginning				$ 57
Restructuring charges		$ 0	$ (3)	(1)	[1]	$ 19
Payments				(33)
Remaining accrual, ending		23		23
2013 Actions
Restructuring Reserve
Restructuring charges	[1]	0	(3)	(1)		25
2013 Actions | Severance and benefits cost
Restructuring Reserve
Accrual, beginning				22
Restructuring charges	[1]			(1)
Payments				(11)
Remaining accrual, ending		10		10
2013 Actions | Other Charges
Restructuring Reserve
Accrual, beginning				9
Restructuring charges	[1]			0
Payments				(4)
Remaining accrual, ending		5		5
Prior Actions
Restructuring Reserve
Restructuring charges	[1]	0	$ 0	0		$ (6)
Prior Actions | Severance and benefits cost
Restructuring Reserve
Accrual, beginning				26
Restructuring charges	[1]			0
Payments				(18)
Remaining accrual, ending		$ 8		$ 8

[1] Includes changes in estimates.