Class of Warrant or Right, Stated Percentage

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- Definition

Class of Warrant or Right, Threshold Percentage of Stock Price Trigger

+ References

No definition available.

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- Definition

Class of Warrant or Right, Trading Days Measurement Period

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No definition available.

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- Definition

Fair market value of common stock, Percentage.

+ References

No definition available.

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- Definition

Share based compensation arrangement by share based payment award maximum amount per employee.

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No definition available.

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- Definition

Unrecognized compensation forfeited rate.

+ References

No definition available.

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- Definition

Exercise price per share or per unit of warrants or rights outstanding.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(i)(4))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

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- Definition

The number of warrants issued in exchange for the original debt being converted in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 50
-Paragraph 5
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- Definition

Unrecognized cost of unvested share-based compensation awards.

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- Definition

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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- Definition

Amount of decrease in the reserve for full or partial settlement through consideration other than cash.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 420
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SAB TOPIC 5.P.4(b)(2))
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- Definition

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.

+ References

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- Definition

The estimated dividend rate (a percentage of the share price) to be paid (expected dividends) to holders of the underlying shares over the option's term.

+ References

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- Definition

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.

+ References

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- Definition

The estimated measure of the maximum 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.

+ References

No definition available.

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- Definition

The estimated measure of the minimum 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.

+ References

No definition available.

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- Definition

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

+ References

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- Definition

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

+ References

No definition available.

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- Definition

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

+ References

No definition available.

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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

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).

+ References

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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.

+ References

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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.

+ References

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- Definition

Number of shares for which recognition of compensation cost was accelerated.

+ References

No definition available.

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- Definition

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.

+ References

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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
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-Subparagraph (f)(2)(i)
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- Definition

Number of shares issued during the period as a result of an employee stock purchase plan.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
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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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Reference 1: http://www.xbrl.org/2003/role/presentationRef
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Stockholders' Equity - Additional Information (Details) - USD ($)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Threshold percentage of stock price trigger	0.625%
Number of warrants issued (in shares)				13,490,236
Striking price of Warrants (USD per share)				$ 53.8475
Trading days measurement period (in days)	160 days
Stated interest rate for Warrants	1.125%
Unrecognized compensation expense	$ 19,000,000
Unrecognized compensation forfeited rate	11.80%
Weighted average grant date fair value of stock options granted (usd per share)	$ 41.43
Common stock issued during period (in shares)	351,000	410,000	302,000
Separation Costs - Former Executives
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restructuring settled without cash	$ 23,000,000
Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average period of unrecognized compensation expense	2 years 2 months
Accelerating vesting awards (in shares)	133,957
Performance Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average period of unrecognized compensation expense	5 months
Accelerating vesting awards (in shares)	153,574
Performance Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average period of unrecognized compensation expense	1 year 7 months
Accelerating vesting awards (in shares)	139,272
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation expense	$ 15,000,000
Weighted average period of unrecognized compensation expense	2 years 9 months
Risk free interest rate	2.30%
Expected volatility rate	38.40%
Dividend yield	0.00%
Expected term of awards	8 years 5 months
Options exercised, intrinsic value	$ 2,000,000	$ 1,000,000	$ 6,000,000
Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)	3,000,000
Dividend yield	0.00%
Expected term of awards	6 months 4 days
Employee purchase price as a percentage of stock price	85.00%
Maximum annual contribution per employee	$ 25,000
Risk-free interest rate, minimum	0.10%
Risk-free interest rate, maximum	1.10%
Minimum expected volatility rate inputs for fair value measurement	30.00%
Maximum expected volatility rate inputs for fair value measurement	40.00%
Common Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation (in shares)	857,000
2011 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)	4,500,000.0
2011 Plan \| Restricted Stock Awards
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum award vesting period	4 years
2011 Plan \| Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum award vesting period	4 years
Stock option expiration period	10 years