Stockholders' Equity - Activity Under Stock Option Plans (Detail)	12 Months Ended
Dec. 31, 2019 $ / shares shares
Number of Shares Underlying Stock Options
Exercised (shares)	(8,187)
Outstanding ending balance (shares)	0
Weighted Average Exercise Price per Share
Exercised (usd per share) \| $ / shares	$ 8.07

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.

+ References

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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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- Definition

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

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