Share-Based Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 31.0	$ 30.6	$ 34.3
Unrecognized compensation costs	$ 29.3
Unrecognized compensation cost, non-vested awards, period of recognition	1 year 3 months 22 days
Weighted average grant date fair value (usd per share)	$ 11.72	$ 11.18	$ 12.34
Intrinsic value, exercised in period	$ 12.7	$ 40.0	$ 8.2
Employee stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock option term	10 years
Vesting percentage	25.00%
Vesting period	4 years
Share-based compensation expense	$ 23.2	23.0	25.5
Unrecognized compensation cost, non-vested awards, period of recognition	1 year 4 months 4 days
Unrecognized compensation cost, options, period of recognition	$ 24.0
Employee stock options [Member] \| Tranche One [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	1 year
Employee stock options [Member] \| Tranche Two [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Director stock options [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	1 year
Restricted stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting percentage	25.00%
Cumulative awards granted (shares)	27,422,350
Outstanding awards (shares)	8,023,696
Share-based compensation expense	$ 6.6	$ 6.1	$ 7.6
Unrecognized compensation costs	$ 5.3
Unrecognized compensation cost, non-vested awards, period of recognition	1 year 1 month 24 days
Weighted average grant date fair value of shares awarded (usd per share)	$ 33.63	$ 28.37	$ 29.84
Shares vested in period, fair value	$ 8.7	$ 7.1	$ 7.1
2010 ESPP [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares authorized (shares)	2,000,000
Percentage discount from offering date	85.00%
Maximum employee subscription rate	5.00%
Available for future grant (shares)	1,067,432
2010 ESPP [Member] \| Employee stock purchase plan shares [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 1.2	$ 1.5	$ 1.2
Stock issued (shares)	136,378	184,432	155,867
Offering period	6 months
2013 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Available for future grant (shares)	4,411,820

Share-based Compensation Arrangement by Share-based Payment Award, Offering Period

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Share-based Compensation by Share-based Payment Award, Cumulative Shares Granted

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- Definition

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.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
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Percentage of employer's matching contributions to a defined contribution plan that vests in a given year.

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Unrecognized cost of unvested share-based compensation awards.

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Weighted average period over which unrecognized compensation is expected to be recognized for equity-based compensation plans, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Unrecognized cost of unvested options awarded to employees as compensation.

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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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Discount rate from fair value on offering date that participants pay for shares.

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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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Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

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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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The highest percentage of annual salary that an employee is permitted to utilize with respect to the plan.

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Number of equity instruments other than options outstanding, including both vested and non-vested instruments.

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The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested).

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The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

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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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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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Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Number of shares (or other type of equity) issued during the period as a result of any equity-based compensation plan other than an employee stock ownership plan (ESOP), net of any shares forfeited. Shares issued could result from the issuance of restricted stock, the exercise of stock options, stock issued under employee stock purchase plans, and/or other employee benefit plans.

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-Publisher FASB
-Name Accounting Standards Codification
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