Schedule II - Valuation And Qualifying Accounts And Reserves (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Allowance For Obsolescence Of Inventories [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of year	$ 530	$ 509	$ 488
Changes charged to statement of operations accounts	34	32	40
Sales, retirements and transfers	11	(11)	(19)
Balance at end of year	575	530	509
Allowance For Uncollectible Accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of year	58	58	49
Changes charged to statement of operations accounts	4	5	6
Write-offs (net of recoveries)	(10)	(5)	3
Balance at end of year	52	58	58
Reserves For Environmental Remediation Costs [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Balance at beginning of year	17	18	18
Changes charged to statement of operations accounts	(2)		1
Payments	(1)	(1)	(1)
Balance at end of year	$ 14	$ 17	$ 18