The number of distinct awards granted.

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- Definition

The grant-date, total value of options granted during the reporting period.

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Period from grant date within which a performance condition must be met for the first half of each award to vest, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Following the satisfaction of a performance condition, the vesting period for the remaining half of the award, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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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

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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No definition available.

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- Definition

The number of shares under options that were cancelled during the reporting period as a result of occurrence of a terminating event specified in contractual agreements pertaining to the stock option plan.

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- Definition

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

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No definition available.

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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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Amount by which the current fair value of the underlying stock exceeds the exercise price of options outstanding.

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- Definition

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

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- Definition

A roll forward is a reconciliation of a concept from the beginning of a period to the end of a period.

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

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Amount by which current fair value of underlying stock exceeds exercise price of fully vested and expected to vest exercisable or convertible options. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Number of fully vested and expected to vest exercisable options that may be converted into shares under option plan. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Weighted-average exercise price, at which grantee can acquire shares reserved for issuance, for fully vested and expected to vest exercisable or convertible options. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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- Definition

Weighted average price at which option holders acquired shares when converting their stock options into shares.

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No definition available.

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Weighted average price at which grantees could have acquired the underlying shares with respect to stock options that were terminated.

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Weighted average per share amount at which grantees can acquire shares of common stock by exercise of options.

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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.

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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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Weighted average remaining contractual term for fully vested and expected to vest exercisable or convertible options, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. Includes, but is not limited to, unvested options for which requisite service period has not been rendered but that are expected to vest based on achievement of performance condition, if forfeitures are recognized when they occur.

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Number of share options (or share units) exercised during the current period.

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Stock-Based Compensation - Performance-Based Stock Options (Details) $ / shares in Units, $ in Thousands		12 Months Ended
	Feb. 28, 2017 USD ($) award $ / shares shares	Dec. 31, 2019 USD ($) $ / shares shares	Dec. 31, 2018 USD ($) $ / shares shares
Performance-based stock options
Stock-Based Compensation
Number of distinct awards \| award	3
Total grant value \| $	$ 5,900
Vesting period upon satisfaction of performance condition	2 years
Performance condition achievement window	4 years 3 months 18 days
Expiration term	7 years
Number of options outstanding
Outstanding options as of the beginning of the period (in shares) \| shares		555,000
Granted (in shares) \| shares	555,000	0
Exercised (in shares) \| shares		0
Forfeited and cancelled (in shares) \| shares		0
Outstanding options as of the end of the period (in shares) \| shares		555,000	555,000
Weighted- average exercise price (Per share)
Outstanding options as of the beginning of the period (in dollars per share)		$ 31.72
Granted (in dollars per share)		0
Exercised (in dollars per share)		0
Forfeited and cancelled (in dollars per share)		0
Outstanding options as of the end of the period (in dollars per share)		$ 31.72	$ 31.72
Weighted-average remaining contractual term
Weighted-average remaining contractual term (in years)		4 years 1 month 28 days	6 years
Aggregate intrinsic value \| $		$ 36,941	$ 0
Options vested and exercisable
Options vested and exercisable - number of options outstanding (in shares) \| shares		427,812
Options vested and exercisable - weighted-average exercise price (in dollars per share)		$ 31.72
Options vested and exercisable - weighted-average remaining contractual term		4 years 1 month 28 days
Options vested and exercisable - aggregate intrinsic value \| $		$ 28,475
$13.48 grant date fair value
Stock-Based Compensation
Grant date fair value (in dollars per share)	$ 13.48
Derived service period as adjusted	3 years 1 month 6 days
$10.26 grant date fair value
Stock-Based Compensation
Grant date fair value (in dollars per share)	$ 10.26
Derived service period as adjusted	3 years 10 months 24 days
$8.41 grant date fair value
Stock-Based Compensation
Grant date fair value (in dollars per share)	$ 8.41
Derived service period as adjusted	4 years 7 months 6 days