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			$ 51	$ 60
Charged to Costs and Expenses		$ 12	13	0
Charged to Other Accounts	[1]	(10)	(7)	(4)
Deductions	[2]	2	7	5
Balance at End of Period		50	50	51
Allowances for Sales Discounts [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period			20	20
Charged to Costs and Expenses		256	265	275
Charged to Other Accounts	[1]	(1)	(1)	(1)
Deductions	[3]	256	268	274
Balance at End of Period		15	16	20
Deferred Taxes [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at Beginning of Period			197	215
Charged to Costs and Expenses		78	30	(11)
Charged to Other Accounts		0	0	0
Deductions	[4]	19	12	7
Balance at End of Period		$ 274	$ 215	$ 197

[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.