Share-Based Associate Compensation Plans (Narrative) (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award
Maximum number of shares awarded to each full-time employee for their service	10
Share based compensation	$ 13	$ 12	$ 11
Tax benefit from compensation expense	6	6	5
Options exercised, intrinsic value	13	17	6
Options vested, intrinsic value	9	15	5
Unrecognized compensation costs related to non-vested awards	21
Expected weighted-average period to recognize the unrecognized compensation costs related to non-vested awards	1 year 8 months 18 days
Proceeds from stock options exercised	22	25	10
Shares of common stock granted in period	401,000
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award
Awards exercise peirod	10 years
Awards vesting period	3 years
Proceeds from stock options exercised	22	25	10
Shares repurchased	378,276	577,745	311,524
Shares repurchased, value	19	28	12
Weighted average remaining contractual term	8 years 4 months 10 days
Weighted-average remaining contractual life for exercisable awards	3 years 4 months 10 days
Shares authorized to be granted under the shareholder-approved plans	17,300,000
Shares available for future issuance under the plans	6,200,000
Stock Options \| Directors
Share-based Compensation Arrangement by Share-based Payment Award
Shares of common stock granted in period	20,760
Restricted Stock Units \| Service Based Shares
Share-based Compensation Arrangement by Share-based Payment Award
Awards vesting period	3 years
Awards other than options vested, intrinsic value	14	15	1
Restricted Stock Units \| Performance Based Shares
Share-based Compensation Arrangement by Share-based Payment Award
Awards vesting period	3 years	3 years
Awards other than options vested, intrinsic value	$ 3	$ 3	$ 2
Risk-free rates, minimum	0.00%	0.00%	0.00%
Risk-free rates, maximum	200.00%	200.00%	125.00%
Number of shares issued	59,615
Expected volatility	2.88%	2.87%
Dividend yield	3.74%	3.63%
Risk-free rates	0.66%	0.40%

Maximum number of shares awarded to each full-time employee for their service

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Amount of difference between fair value of the underlying shares vested during the period.

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Share Based Compensation Arrangement by Share Based Payment Award, Exercise Period

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Share-based Compensation Arrangement by Share-based Payment Award, Options, Expected to Vest, Weighted Average Remaining Contractual Term

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Share Based Compensation Arrangement by Share Based Payment Award, Options, Vested in Period, Total Intrinsic Value

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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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Unrecognized cost of unvested share-based compensation awards.

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Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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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 cash inflow associated with the amount received from holders exercising their stock options. This item inherently excludes any excess tax benefit, which the entity may have realized and reported separately.

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Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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

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

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The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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Net number of share options (or share units) granted during the period.

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Weighted average remaining contractual term of exercisable stock options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Number of shares of stock issued as of the balance sheet date, including shares that had been issued and were previously outstanding but which are now held in the treasury.

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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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Equity impact of the value of stock that has been repurchased during the period and has not been retired and is not held in treasury. Some state laws may mandate 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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