Valuation and Qualifying Accounts (Schedule of Valuation and Qualifying Accounts) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2008
Allowance for Doubtful Accounts [Member]
Balance at Beginning of Period	$ 57				$ 62		$ 68
Charged to Costs and Expenses	9		5		7
Charged to Other Accounts	0	[1]	(5)	[1]	0	[1]
Deductions	6	[2]	5	[2]	13	[2]
Balance at End of Period	60		57				68
Deferred Taxes [Member]
Balance at Beginning of Period	229				287		244
Charged to Costs and Expenses	(18)		(51)		35
Charged to Other Accounts	0		0		0
Deductions	(4)	[3]	7	[3]	(8)	[3]
Balance at End of Period	215		229				244
Allowances for Sales Discounts [Member]
Balance at Beginning of Period	21				18		21
Charged to Costs and Expenses	280		275		266
Charged to Other Accounts	0	[1]	0	[1]	0	[1]
Deductions	281	[4]	272	[4]	269	[4]
Balance at End of Period	$ 20		$ 21				$ 21

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

[2] Primarily uncollectible receivables written off.

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

[4] Sales discounts allowed.