Stock-Based Compensation (PSUs, RSUs and Restricted Stock) - Additional Information (Detail) $ in Millions	9 Months Ended
Sep. 30, 2020 USD ($) shares
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Options available for issuance under stockholders-approved equity plan	3,600,000
2015 Employee Stock Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of additional shares of common stock granted	0
2010 Directors Stock Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of additional shares of common stock granted	0
2020 Employee Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares of common stock authorized	2,800,000
Multiplier used when issuing PSUs, restricted stock and RSUs	1
Contractual term	10 years
2020 Directors Stock Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares of common stock authorized	400,000
Multiplier used when issuing PSUs, restricted stock and RSUs	1
Forfeiture of stock increase in issuance of common stock	1
Contractual term	10 years
Performance Stock Units (PSUs) [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share issued	300,000
Performance target period	3 years
Performance Stock Units (PSUs) [Member] \| Minimum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of performance stock units granted	0.00%
Performance Stock Units (PSUs) [Member] \| Maximum [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Percentage of performance stock units granted	142.80%
Market-Based PSUs, RSUs and Restricted Stock [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation expense related to other than options \| $	$ 10.6
Recognition period of unvested compensation expense	2 years 3 months 18 days
Performance-Based PSUs [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Unrecognized compensation expense related to other than options \| $	$ 2.3
Recognition period of unvested compensation expense	2 years 3 months 18 days
PSUs, RSUs and Restricted Stock [Member] \| 2020 Employee Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period	4 years
PSUs, RSUs and Restricted Stock [Member] \| 2015 Employee Incentive Plan to 2020 Employee Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Forfeiture of stock increase in issuance of common stock	2.5
Stock Options [Member] \| 2020 Employee Incentive Plan [Member]
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Vesting period	4 years

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Share based compensation arrangement by share based payment award forfeiture of common stock multiplier used in determining issuable shares.

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Share based compensation arrangement by share based payment award number of additional shares granted.

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Share-based compensation arrangement by share-based payment award, common stock multiplier used in determining issuable shares.

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Weighted-average period over which cost not yet recognized is expected to be recognized for 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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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.

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

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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.

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Number of shares issued under share-based payment arrangement.

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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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