| Capital [Abstract] | Period [Axis] |
|---|
2016-01-01 - 2016-12-31 |
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Capital [Abstract] | |
Summary of Stock Option Activity | A summary of stock option activity for the year ended December 31, 2016 is as follows: | | | | | | | | | | | | | | | Number of Shares | | Weighted-Average Option Price per Share | | Weighted-Average Remaining Contractual Life (Years) | | Aggregate Intrinsic Value | Outstanding at January 1, 2016 | 6.0 |
| | $ | 87.23 |
| | | | | Granted | 1.4 |
| | 131.84 |
| | | | | Exercised | (1.5 | ) | | 64.39 |
| | | | | Forfeited or expired | (0.3 | ) | | 118.58 |
| | | | | Outstanding at December 31, 2016 | 5.6 |
| | 102.80 |
| | 5.19 | | $ | 234.0 |
| Exercisable at December 31, 2016 | 3.7 |
| | 88.04 |
| | 3.62 | | $ | 207.8 |
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Summary of Nonvested Restricted Stock Activity Including Restricted Stock Units | A summary of the status of nonvested restricted stock activity, including restricted stock units, for the year ended December 31, 2016 is as follows: | | | | | | | | | Restricted Stock Shares and Units | | Weighted-Average Grant Date Fair Value per Share | Nonvested at January 1, 2016 | 2.7 |
| | $ | 101.66 |
| Granted | 1.1 |
| | 131.81 |
| Vested | (1.4 | ) | | 82.26 |
| Forfeited | (0.3 | ) | | 119.94 |
| Nonvested at December 31, 2016 | 2.1 |
| | 127.68 |
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Summary of Weighted-Average Assumptions Used to Estimate the Fair Values of Options Granted During the Periods | The following weighted-average assumptions were used to estimate the fair values of options granted during the years ended December 31: | | | | | | | | | | | 2016 | | 2015 | | 2014 | Risk-free interest rate | 1.76 | % | | 1.96 | % | | 2.16 | % | Volatility factor | 32.00 | % | | 31.00 | % | | 35.00 | % | Dividend yield (annual) | 2.00 | % | | 1.70 | % | | 2.00 | % | Weighted-average expected life (years) | 4.10 |
| | 4.00 |
| | 3.75 |
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Schedule of Weighted-Average Fair Values Determined For the Periods | The following weighted-average fair values were determined for the years ending December 31: | | | | | | | | | | | | | | 2016 | | 2015 | | 2014 | Options granted during the year | $ | 30.56 |
| | $ | 33.97 |
| | $ | 22.41 |
| Restricted stock awards granted during the year | 131.81 |
| | 147.00 |
| | 90.53 |
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Summary of Cash Dividend Activity | A summary of the cash dividend activity for the years ended December 31, 2016 and 2015 is as follows: | | | | | | | | | | | | | | Declaration Date | | Record Date | | Payment Date | | Cash Dividend per Share | | Total | Year ended December 31, 2016 | | | | | | | February 18, 2016 | | March 10, 2016 | | March 25, 2016 | | $ | 0.6500 |
| | $ | 170.7 |
| April 26, 2016 | | June 10, 2016 | | June 24, 2016 | | 0.6500 |
| | 170.9 |
| July 26, 2016 |
| September 9, 2016 |
| September 26, 2016 | | 0.6500 |
| | 171.1 |
| November 1, 2016 | | December 5, 2016 | | December 21, 2016 | | 0.6500 |
| | 171.3 |
| | | | | | | | | | Year ended December 31, 2015 | | | | | | | January 27, 2015 | | March 10, 2015 | | March 25, 2015 | | $ | 0.6250 |
| | $ | 166.6 |
| April 28, 2015 | | June 10, 2015 | | June 25, 2015 | | 0.6250 |
| | 163.9 |
| July 28, 2015 | | September 10, 2015 | | September 25, 2015 | | 0.6250 |
| | 163.0 |
| October 27, 2015 | | December 4, 2015 | | December 21, 2015 | | 0.6250 |
| | 163.1 |
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Summary of Share Repurchases | A summary of common stock repurchases for the year ended December 31, 2015 is as follows: | | | | | | 2015 | Shares repurchased | 10.4 |
| Average price per share | $ | 145.50 |
| Aggregate cost | $ | 1,515.8 |
| Authorization remaining at end of year | $ | 4,175.9 |
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