Aggregate number of options granted.

No definition available.

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- Definition

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5047-113901

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-Publisher FASB
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-SubTopic 10
-Section S99
-Paragraph 1
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-Section 50
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-URI http://asc.fasb.org/extlink&oid=120381028&loc=d3e5070-113901

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- References

No definition available.

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- Definition

Period over which grantee's right to exercise award under share-based payment arrangement is no longer contingent on satisfaction of service or performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents reported fact of one year, five months, and thirteen days. Includes, but is not limited to, combination of market, performance or service condition.

+ 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 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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- Definition

Number of shares authorized for issuance under share-based payment arrangement.

+ References

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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

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

+ References

No definition available.

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- Definition

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

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
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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 award under share-based payment arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents 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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Employee Benefit Plans - Assumptions For Estimating Fair Value (Details) - USD ($) $ in Millions		12 Months Ended
	May 12, 2011	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Employee Benefit Plans
Compensation cost		$ 14.4	$ 8.8	$ 7.4
Assumptions for estimating fair value
Dividend Yield		0.00%
Stock options
Employee Benefit Plans
Number of options outstanding (in shares)		10,284,498	23,013,590
Compensation cost		$ 6.8	$ 6.0	$ 6.4
Stock options granted		3,509,549	3,221,892	2,679,667
Assumptions for estimating fair value
Expected term of options (years)		6 years	6 years	6 years
Stock options \| Minimum
Assumptions for estimating fair value
Risk free rate (as a percent):		0.37%	1.52%	2.81%
Volatility (as a percent):		64.19%	69.32%	98.31%
Stock options \| Maximum
Assumptions for estimating fair value
Risk free rate (as a percent):		1.37%	2.53%	2.88%
Volatility (as a percent):		68.18%	87.94%	98.89%
the 2011 Plan \| Stock options
Employee Benefit Plans
Maximum number of common stock shares available for issuance	1,000,000	42,400,000
Aggregate number of options granted (in shares)		10,200,000
Number of options available for issuance (in shares)		800,000
Expiration period		10 years
Stock options granted	0
the 2011 Plan \| Stock options \| Minimum
Employee Benefit Plans
Vesting period		1 year
the 2011 Plan \| Stock options \| Maximum
Employee Benefit Plans
Vesting period		3 years
the 2011 Plan \| Employees \| Stock options
Employee Benefit Plans
Vesting period		3 years
Expiration period		10 years
the 2011 Plan \| Board of Directors \| Stock options
Employee Benefit Plans
Vesting period		1 year