Consolidated Statement of Changes in Equity (Parenthetical) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Statement Of Changes in Equity
Tax benefit (income tax) from change in pension and post-retirement benefit plans	$ 796	$ 224	$ (569)
Tax benefit (income tax) from adjustment for sale of securities	(21)	(61)	(66)
Tax benefit (income tax) from unrealized cash flow hedging gain (loss)	36	18	(106)
Common Stock issued under employee plans, shares	7.2	11.8	11.9
Tax benefit from Common Stock issued under employee plans	$ 81	$ 94	$ 50
Common Stock contributed to defined benefit pension plans, shares	5.7	3.8
Common Stock repurchased, shares	26.9	31.0	19.1

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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Tax effect of the gross appreciation or the gross loss, net of reclassification adjustment, in the value of the total unsold available-for-sale securities at the end of an accounting period.

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- Definition

Tax effects of the increase (decrease) to accumulated comprehensive income during the period related to benefit plans. While for technical reasons this element has no balance attribute, the default assumption is a credit balance consistent with its label.

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- Definition

Total tax effect of the change in accumulated gains and losses from derivative instruments designated and qualifying as the effective portion of cash flow hedges. The change includes an entity's share of an equity investee's increase or decrease in deferred hedging gains or losses. While for technical reasons this element has no balance attribute, the default assumption is a credit balance consistent with its label.

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- Definition

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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