The discount rate from market value on specific date that participants pay for shares.

No definition available.

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- Definition

Represents the total fair value of nonvested equity stock units granted during the period.

+ References

No definition available.

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- Definition

Represents the total fair value of options for granted during the period.

+ References

No definition available.

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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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- 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.

+ References

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- Definition

Estimated period over which an employee is required to provide service in exchange for the equity-based payment award, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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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

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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.

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-Publisher FASB
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-SubTopic 10
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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 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.

+ References

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- Definition

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

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- Definition

Number of options outstanding, including both vested and non-vested options.

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- Definition

Percentage of vesting of share-based compensation awards.

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Equity Incentive Plans and Stock-Based Compensation (Details Textual) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018	Dec. 31, 2018
Stock-Based Compensation
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions, Expected Dividend Rate	0.00%
Minimum [Member]
Stock-Based Compensation
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	0.00%
Maximum [Member]
Stock-Based Compensation
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Rights, Percentage	200.00%
Stock Compensation Plan [Member]
Stock-Based Compensation
Shares available for issuance	4,515,733		10,074,046
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures	0
Employee Stock Option [Member]
Stock-Based Compensation
Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number	2,497,073		3,235,891
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Net of Forfeitures	0	551,479
Share Based Compensation Arrangement by Share Based Payment Award Options, Grants in Period, Total Fair Value		$ 2.3
Stock-based compensation	$ 0.2	0.6
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	$ 3.5
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition	2 years 6 months 22 days
Employee Stock [Member]
Stock-Based Compensation
Shares available for issuance	2,294,878
Share Based Compensation Arrangement by Share Based Payment Award Discount from Market Price Specific Date	15.00%
Stock-based compensation	$ 0.5	$ 0.5
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	$ 0.2
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition	1 month
Restricted Stock and Stock Units [Member]
Stock-Based Compensation
Granted (in shares)	3,389,337	2,076,197
Stock-based compensation	$ 6.4	$ 6.5
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized	$ 53.7
Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition	2 years 10 months 17 days
Share Based Compensation Arrangement by Share Based Payment Award Equity Instruments Other than Options Nonvested Requisite Service Period	4 years
Share Based Compensation Arrangement by Share Based Payment Award Equity Instruments Other than Options Nonvested Grants in Period Total Fair Value	$ 32.2	$ 26.8
Director [Member] \| Restricted Stock and Stock Units [Member]
Stock-Based Compensation
Share Based Compensation Arrangement by Share Based Payment Award Equity Instruments Other than Options Nonvested Requisite Service Period	1 year