Valuation and Qualifying Accounts (Valuation and Qualifying Account Activity) (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2012		Dec. 31, 2011		Dec. 31, 2010
Allowance For Doubtful Accounts
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at January 1	$ 45	[1]	$ 49		$ 16
Charged to Earnings	8	[1]	7		41
Used	(4)	[1]	(4)		(2)
Adjustments	2	[1],[2]	(7)	[2]	(6)	[2]
Balance at December 31	51	[1]	45	[1]	49
Allowance For Losses On Long-Term Receivables
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at January 1	10	[1]	1		7
Charged to Earnings	0	[1]	10		0
Used	0	[1]	(1)		(6)
Adjustments	(10)	[1],[2]	0	[2]	0	[2]
Balance at December 31	0	[1]	10	[1]	1
Inventory Reserves
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at January 1	170		157		140
Charged to Earnings	67		37		67
Used	(73)		(30)		(34)
Adjustments	(1)	[2]	6	[2]	(16)	[2]
Balance at December 31	163		170		157
Customer Reserves
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at January 1	125		117		97
Charged to Earnings	456		580		427
Used	(416)		(565)		(374)
Adjustments	(21)	[2]	(7)	[2]	(33)	[2]
Balance at December 31	$ 144		$ 125		$ 117

[1] During 2012, the adjustment of $10 million within Allowance for Losses on Long-term Receivables relates to a reclass from non-current to current.

[2] Adjustments include translation adjustments