Consolidated Statement of Changes in Equity (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Statement Of Changes in Equity
Common Stock issued under employee plans, shares	8,000,000	7,200,000	11,800,000
Tax benefit from Common Stock issued under employee plans	$ 67	$ 81	$ 94
Common Stock contributed to defined benefit pension plans, shares	0	5,700,000	3,800,000
Common Stock repurchased, shares	0	26,900,000	31,000,000
Treasury stock reissued under employee plans, shares	3,600,000	0	0

Tax benefit associated with any equity-based compensation plan other than an employee stock ownership plan (ESOP). The tax benefit results from the deduction by the entity on its tax return for an award of stock that exceeds the cumulative compensation cost for common stock or preferred stock recognized for financial reporting. Includes any resulting tax benefit that exceeds the previously recognized deferred tax asset (excess tax benefits).

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Number of shares (or other type of equity) issued during the period as a result of any equity-based compensation plan other than an employee stock ownership plan (ESOP), net of any shares forfeited. Shares issued could result from the issuance of restricted stock, the exercise of stock options, stock issued under employee stock purchase plans, and/or other employee benefit plans.

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- Definition

Number of shares that have been repurchased during the period and have not been retired and are not held in treasury. Some state laws may govern the circumstances under which an entity may acquire its own stock and prescribe the accounting treatment therefore. This element is used when state law does not recognize treasury stock.

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