Valuation and Qualifying Accounts (Valuation and Qualifying Account Activity) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Allowance for doubtful accounts
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at January 1		$ 35	$ 53	$ 50
Charged to Earnings		9	19	13
Used		(17)	(35)	(8)
Adjustments	[1]	1	(2)	(2)
Balance at December 31		28	35	53
Inventory reserves
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at January 1		131	125	112
Charged to Earnings		24	24	25
Used		(13)	(15)	(14)
Adjustments	[1]	0	(3)	2
Balance at December 31		$ 142	$ 131	$ 125

[1] Adjustments include translation adjustments