Consolidated Balance Sheet (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Consolidated Balance Sheet
Common stock, par value per share (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares issued (in shares)	944,033,056us-gaap_CommonStockSharesIssued
Treasury stock (in shares)	308,898,462us-gaap_TreasuryStockShares	280,736,817us-gaap_TreasuryStockShares
Allowances for doubtful accounts receivable	$ 94	$ 104
Common stock, Shares outstanding (in shares)	635,134,594us-gaap_CommonStockSharesOutstanding	663,296,239us-gaap_CommonStockSharesOutstanding

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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Number of common and preferred shares that were previously issued and that were repurchased by the issuing entity and held in treasury on the financial statement date. This stock has no voting rights and receives no dividends.

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