Consolidated Balance Sheet (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	Dec. 31, 2011	Dec. 31, 2010
Consolidated Balance Sheet
Common stock, par value per share (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares issued (in shares)	944,033,056
Treasury stock (in shares)	249,063,015	232,055,448
Allowances for doubtful accounts receivable	$ 108	$ 98
Common stock, Shares outstanding (in shares)	694,970,041	711,977,608

A valuation allowance for trade and other receivables due to an Entity within one year (or the normal operating cycle, whichever is longer) that are expected to be uncollectible.

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