|**Share-Based Associate Compensation Plans (Tables)**                              | 12 Months Ended                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
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|**Share-based Compensation Arrangement by Share-based Payment Award [Line Items]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Stock Option Information                                                           | is a summary of option information for the year 2016:(Dollars in millions, shares in thousands)SharesWeighted-averageexercise priceAggregateintrinsicvalueWeighted-averageremaining contractuallifeOutstanding option shares at January 1, 20163,872$39.78Granted35961.47Exercised(863)38.64Forfeited or expired(356)44.66Outstanding option shares at December 31, 20163,01242.12$1015.05 yearsOptions exercisable at end of period2,319$38.01$884.04 years                    
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|(Dollars in millions, shares in thousands)                                         |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Outstanding option shares at January 1, 2016                                       |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Granted                                                                            |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Exercised                                                                          |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Forfeited or expired                                                               |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Outstanding option shares at December 31, 2016                                     |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
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|Options exercisable at end of period                                               |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
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|Restricted Stock Unit Information                                                  | Below is a summary of service-based and performance-based share information, assuming a target payout for performance-based shares, for the year2016:(Shares in thousands)Service-basedsharesWeighted-average grantdate fair valuePerformance-basedsharesWeighted-average grantdate fair valueNonvested at January 1, 2016902$43.15256$42.35Granted32356.396870.68Vested(313)40.99(25)44.82Forfeited or canceled(24)48.31(63)44.82Nonvested at December 31, 201688848.5923649.64
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|(Shares in thousands)                                                              |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Nonvested at January 1, 2016                                                       |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Granted                                                                            |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Vested                                                                             |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Forfeited or canceled                                                              |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Nonvested at December 31, 2016                                                     |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
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|Stock Options                                                                      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|**Share-based Compensation Arrangement by Share-based Payment Award [Line Items]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Assumptions Used In Option Grants Issued                                           | The following weighted average assumptions were used in determining fair value for option grants issued:201620152014Weighted-average expected term8 years8-9 years8-9 yearsExpected volatility24.88-25.75%25.04-26.15%25.20-26.22%Dividend yield2.58-3.12%3.52%3.76%Risk-free rates1.44-1.60%1.94-2.01%2.42-2.62%Weighted-average fair value of options granted during the period$13.21$11.15$10.16                                                                             
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|Weighted-average expected term                                                     |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Expected volatility                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Dividend yield                                                                     |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Risk-free rates                                                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Weighted-average fair value of options granted during the period                   |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
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|Performance Based Shares                                                           |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|**Share-based Compensation Arrangement by Share-based Payment Award [Line Items]** |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Assumptions Used In Option Grants Issued                                           | The following assumptions were used in determining fair value for performance-based grants issued:201620152014Expected term2.44-2.88 years2.88 years2.88 yearsExpected volatility15.42-33.64%13.78-34.69%18.69-41.21%Dividend yield2.58-3.12%3.52%3.74%Risk-free rates0.77-0.87%0.99%0.66%                                                                                                                                                                                      
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|Expected term                                                                      |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Expected volatility                                                                |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Dividend yield                                                                     |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
|Risk-free rates                                                                    |                                                                                                                                                                                                                                                                                                                                                                                                                                                                                 
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X- DefinitionTabular disclosure of the number and weighted-average grant date fair value for restricted stock units that were outstanding at the beginning and end of the year, and the number of restricted stock units that were granted, vested, or forfeited during the year.
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