Share-Based Compensation Plans - Narrative (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2016	Mar. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares granted	633,224
Compensation expense on fully vested on options	$ 5.5	$ 4.3
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grant-date fair value	$ 9.5
Restricted Stock Unit Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units granted	1,190,617
Grant-date fair value	$ 69.4
Compensation expense on fully vested equity units	$ 2.0	$ 1.5
Performance Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Units granted	354,606
Grant-date fair value	$ 20.7

Allocated Share-based Compensation Expense On Fully Vested And Expensed On Equity Instruments Other Than Options

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- Definition

Allocated Share-based Compensation Expense On Fully Vested And Expensed On Options

+ References

No definition available.

+ Details

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- Definition

The number of grants made 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).

+ 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 (c)(2)(iii)(1)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

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

+ References

No definition available.

+ Details

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- Definition

Value, before forfeitures, of stock or other type of equity granted of any equity-based compensation plan other than an employee stock ownership plan (ESOP).

+ References

No definition available.

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