Share-Based Compensation Plans (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2011	Sep. 30, 2010	Sep. 30, 2011 Year Plaintiff Segment	Sep. 30, 2010 Year
Amounts of share-based compensation cost recorded in the Consolidated Statement of Income
Pretax share-based compensation expense	$ 86	$ 125	$ 287	$ 400
Income tax benefit	(30)	(42)	(99)	(136)
Total share-based compensation expense, net of taxes	$ 56	$ 83	$ 188	$ 264
The weighted average fair value of options granted, was determined using the following assumptions:
Expected dividend yield			4.30%	4.10%
Risk-free interest rate			2.60%	2.80%
Expected volatility			23.20%	33.70%
Expected life (years)			7.0	6.8

Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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The amount of expense, net of income tax, recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

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The total recognized tax benefit related to compensation cost for equity-based payment arrangements recognized in income during the period.

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The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

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The period of time an equity-based award is expected to be outstanding. An equity-based award's expected term is generally determined based on, among other factors, the instrument's contractual term and the effects of employees' expected exercise and post-vesting employment termination behavior.

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The estimated measure of the percentage by which a share price is expected to fluctuate during a period. Volatility also may be defined as a probability-weighted measure of the dispersion of returns about the mean. The volatility of a share price is the standard deviation of the continuously compounded rates of return on the share over a specified period. That is the same as the standard deviation of the differences in the natural logarithms of the stock prices plus dividends, if any, over the period.

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The risk-free interest rate assumption that is used in valuing an option on its own shares.

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