Stock-Based Compensation Plans - Option Activity under Company's Stock Option Plans (Detail) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
Dec. 31, 2020 USD ($) $ / shares shares
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Outstanding, Number of Stock Options, Beginning Balance \| shares	359
Granted, Number of Stock Options Outstanding \| shares	217
Exercised, Number of Stock Options Outstanding \| shares	(20)
Forfeited or expired, Number of Stock Options Outstanding \| shares	(128)
Outstanding, Number of Stock Options, Ending Balance \| shares	428
Vested or expected to vest, Number of Stock Options Outstanding \| shares	428
Exercisable, Number of Stock Options Outstanding \| shares	175
Outstanding, Weighted Average Exercise Price, Beginning Balance \| $ / shares	$ 17.99
Granted, Weighted Average Exercise Price \| $ / shares	18.12
Exercised, Weighted Average Exercise Price \| $ / shares	11.64
Forfeited or expired, Weighted Average Exercise Price \| $ / shares	20.59
Outstanding, Weighted Average Exercise Price, Ending Balance \| $ / shares	17.57
Vested or expected to vest, Weighted Average Exercise Price \| $ / shares	17.57
Exercisable, Weighted Average Exercise Price \| $ / shares	$ 16.10
Outstanding, Weighted Average Remaining Contractual Term	4 years 7 months 24 days
Vested or expected to vest, Weighted Average Remaining Contractual Term	4 years 7 months 24 days
Exercisable, Weighted Average Remaining Contractual Term	4 years 10 days
Outstanding, Aggregate Intrinsic Value \| $	$ 1,021
Vested or expected to vest, Aggregate Intrinsic Value \| $	1,021
Exercisable, Aggregate Intrinsic Value \| $	$ 685

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The number of shares into which fully or partially vested stock options outstanding as of the balance sheet date can be currently converted under the option plan.

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The weighted-average price as of the balance sheet date at which grantees can acquire the shares reserved for issuance on vested portions of options outstanding and currently exercisable under the stock option plan.

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For presentations that combine terminations, 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 or that expired.

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Weighted average price of options that were either forfeited or expired.

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

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

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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 options outstanding. 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 options outstanding that can 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 options outstanding. 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 price at which option holders acquired shares when converting their stock options into shares.

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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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Amount of difference between fair value of the underlying shares reserved for issuance and exercise price of vested portions of options outstanding and currently exercisable.

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Weighted average remaining contractual term for vested portions of options outstanding and currently exercisable or convertible, 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 options outstanding, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents 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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