Represents the expense 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.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Amount of the cumulative effect on retained earnings net of related income tax effect.

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Amount of the related income tax effect of a cumulative effect on retained earnings.

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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.

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

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Represents the total grant date fair value of option granted during the reporting period.

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Stockholders' Equity - Employee Stock Options (Details) - USD ($) shares in Millions, $ in Millions	1 Months Ended	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2017	Mar. 31, 2016
Stock Incentive Plan 2015 (The 2015 Plan)
Stock options with performance condition
Options granted with performance condition (in shares)		1.9	1.5
ASU 2016-09
Recently Issued Accounting Standards
Cumulative effect on retained earnings, Net of tax		$ (5.8)
Cumulative effect on retained earnings, Tax		(3.2)
ASU 2016-09 \| Stock Incentive Plan 2015 (The 2015 Plan)
Recently Issued Accounting Standards
Cumulative effect on retained earnings, Net of tax		(0.4)
Cumulative effect on retained earnings, Tax		(0.2)
Performance Shares \| Stock Incentive Plan 2015 (The 2015 Plan)
Stock options with performance condition
Options granted with performance condition (in shares)	0.9
Aggregate grant date fair value	$ 53.9
Allocated Share-based Compensation Expense		$ 0.7
Performance Shares \| Stock Incentive Plan 2015 (The 2015 Plan) \| Minimum
Stock options with performance condition
Vesting period (in years)		1 year
Performance Shares \| Stock Incentive Plan 2015 (The 2015 Plan) \| Maximum
Stock options with performance condition
Vesting period (in years)		3 years