Valuation and Qualifying Accounts (Details) (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011		Dec. 31, 2010		Dec. 31, 2009
Movement in Valuation Allowances and Reserves [Roll Forward]
Deductions from reserves	$ 25		$ 61		$ 23
Notes and accounts receivable written off	18		29		21
Credits to profit and loss	3		1		1
Sale of trade accounts receivable (see Note O to the Consolidated Financial Statements)	0		27		0
Miscellaneous other	4		4		1
For Doubtful Receivables [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	128		160		124
Additions to reserves	18		29		59
Deductions from reserves	25	[1]	61	[1]	23	[1]
Balance at end of year	121		128		160
Other Investments and Noncurrent Receivables [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	518		552		442
Additions to reserves	88		73		162
Deductions from reserves	148		107		52
Balance at end of year	458		518		552
Valuation Allowance of Deferred Tax Assets [Member]
Movement in Valuation Allowances and Reserves [Roll Forward]
Balance at beginning of year	682		721		487
Additions to reserves	477		100		286
Deductions from reserves	7		139		52
Balance at end of year	$ 1,152		$ 682		$ 721

[1] 2011 2010 2009(1) Deductions represent: Notes and accounts receivable written off $18 $29 $21Credits to profit and loss 3 1 1Sale of trade accounts receivable (see Note O to the Consolidated Financial Statements) — 27 —Miscellaneous other 4 4 1 $25 $61 $23