It represents the period of monthly vesting of share-based compensation awards.

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.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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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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- References

No definition available.

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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

+ Details

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

+ References

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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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- 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.

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- Definition

Weighted average price at which grantees can acquire the shares reserved for issuance under the stock option plan.

+ References

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- Definition

Percentage of vesting of share-based compensation awards.

+ References

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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.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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- Definition

Weighted average remaining contractual term for option awards outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Share-Based Payments - Inducement Awards Outside of the 2019 Inducement Plan (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended	3 Months Ended
	Jul. 31, 2018	Mar. 31, 2019	Mar. 31, 2018
Share-Based Payments
Share-based compensation expense		$ 1,907	$ 1,244
Inducement Awards Outside of the 2019 Inducement Plan
Share-Based Payments
Share-based compensation expense		$ 109,000,000
Additional disclosures
Weighted-average remaining contractual life		9 years 3 months 18 days
Inducement Awards Outside of the 2019 Inducement Plan \| Non-statutory option
Share-Based Payments
Vesting period	4 years
Options exercise price (in dollars per share)	$ 3.53	$ 2.05
Exercise period	10 years
Fair Value Assumptions
Expected volatility (as a percent)		59.80%
Expected term of options (in years)		6 years 1 month 6 days
Risk-free interest rate (as a percent)		2.90%
Dividend yield (as a percent)		0.00%
Inducement Awards Outside of the 2019 Inducement Plan \| Non-statutory option \| Chief Executive Officer
Share-Based Payments
Options granted during the period	850,000
Inducement Awards Outside of the 2019 Inducement Plan \| Non-statutory option \| Vesting period, year one
Share-Based Payments
Percentage that vests during the period	25.00%
Inducement Awards Outside of the 2019 Inducement Plan \| Non-statutory option \| Vesting period, years 2-4
Share-Based Payments
Percentage that vests during the period	75.00%
Monthly vesting period	36 months
Inducement Awards Outside of the 2019 Inducement Plan \| Non-statutory option \| Upon receipt of FDA approval
Share-Based Payments
Percentage that vests during the period	50.00%
Inducement Awards Outside of the 2019 Inducement Plan \| Non-statutory option \| First anniversary of FDA approval
Share-Based Payments
Percentage that vests during the period	50.00%
Inducement Awards Outside of the 2019 Inducement Plan \| Restricted Stock Units ("RSUs")
Share-Based Payments
Options exercise price (in dollars per share)		$ 3.53
Inducement Awards Outside of the 2019 Inducement Plan \| Restricted Stock Units ("RSUs") \| Chief Executive Officer
Share-Based Payments
Options granted during the period	150,000