Share-based Compensation (Summary of Stock Award Information) (Details) - USD ($) $ / shares in Units, $ in Millions	6 Months Ended
Jun. 30, 2016	Jun. 30, 2015
Assumptions used to estimate fair value of options, SARs and PSARs granted:
Cash received from exercise of options	$ 14.4	$ 37.0
Income tax benefit related to stock-based compensation	$ 29.0	$ 28.0
Employee Stock Option [Member]
Assumptions used to estimate fair value of options, SARs and PSARs granted:
Weighted average grant-date fair value, options (in dollars per share)	$ 10.31	$ 14.73
Total intrinsic value of awards exercised, options	$ 3.1	$ 93.5
Stock Appreciation Rights (SARs) [Member]
Assumptions used to estimate fair value of options, SARs and PSARs granted:
Weighted average grant-date fair value, other than options (in dollars per share)	$ 8.67	$ 10.78
Total intrinsic value of awards exercised, other than options	$ 34.2	$ 40.1
Performance Stock Appreciation Rights (PSARs) [Member]
Assumptions used to estimate fair value of options, SARs and PSARs granted:
Total intrinsic value of awards exercised, other than options	$ 0.0	$ 0.2
Restricted Stock Units (RSUs) [Member]
Assumptions used to estimate fair value of options, SARs and PSARs granted:
Weighted average grant-date fair value, other than options (in dollars per share)	$ 37.93	$ 51.97
PSUs / PGUs [Member]
Assumptions used to estimate fair value of options, SARs and PSARs granted:
Weighted average grant-date fair value, other than options (in dollars per share)	$ 34.09	$ 51.69
Minimum [Member]
Assumptions used to estimate fair value of options, SARs and PSARs granted:
Risk-free interest rate	1.01%	0.96%
Expected life	3 years 2 months 12 days	3 years
Expected volatility	27.40%	23.10%
Maximum [Member]
Assumptions used to estimate fair value of options, SARs and PSARs granted:
Risk-free interest rate	1.46%	1.89%
Expected life	5 years 6 months	5 years 6 months
Expected volatility	37.40%	30.10%

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

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- Definition

The total cash inflow associated with the amount received from holders to acquire the entity's shares under incentive and share awards, including stock option exercises. This item inherently excludes any excess tax benefit, which the entity may have realized and reported separately.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 14
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3255-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Financing Activities
-URI http://asc.fasb.org/extlink&oid=6513228

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- Definition

The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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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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- Definition

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

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- Definition

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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- Definition

The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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- Definition

Intrinsic value of equity-based compensation awards vested. Excludes stock and unit options.

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- Definition

Expected term of share-based compensation awards, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (f)(2)(i)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SAB Topic 14.D.2)
-URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809

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