Stock-Based Associate Compensation Plans (Stock Option Information) (Details) (USD $) In Millions, except Share data in Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2012
Shares
Outstanding at beginning of year	9,357
Granted	536
Exercised	(708)
Forfeited or expired	(1,248)
Outstanding at end of year	7,937
Options exercisable at end of period	6,594
Weighted-average exercise price
Outstanding at beginning of year	$ 36.71
Granted	$ 35.63
Exercised	$ 30.77
Forfeited or expired	$ 35.66
Outstanding at end of year	$ 37.34
Options exercisable at end of period	$ 38.20
Aggregate intrinsic value
Outstanding at end of year	$ 26
Options exercisable at end of period	$ 18

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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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For presentations that combine terminations, the number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan or that expired.

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Weighted average price of options that were either forfeited or expired.

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The number of shares reserved for issuance under stock option agreements awarded under the plan that validly exist and are outstanding as of the balance sheet date, including vested options.

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