Valuation and Qualifying Accounts (Schedule of Valuation and Qualifying Accounts) (Details) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2013	Dec. 31, 2012
Allowance for Doubtful Accounts [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period			$ 50	$ 51
Charged to Costs and Expenses		$ 8	12	13
Charged to Other Accounts	[1]	3	(10)	(7)
Deductions	[2]	11	2	7
Balance at End of Period		50	50	50
Allowances for Sales Discounts [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period			16	20
Charged to Costs and Expenses		254	256	265
Charged to Other Accounts	[1]	0	(1)	(1)
Deductions	[3]	251	256	268
Balance at End of Period		18	15	16
Deferred Taxes [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period			215	197
Charged to Costs and Expenses		(45)	78	30
Charged to Other Accounts		0	0	0
Deductions	[4]	4	19	12
Balance at End of Period		$ 225	$ 274	$ 215

[1] Includes bad debt recoveries and the effects of changes in foreign currency exchange rates.

[2] Primarily uncollectible receivables written off.

[3] Sales discounts allowed.

[4] Represents the net currency effects of translating valuation allowances at current rates of exchange.