Share-Based Compensation Plans - Additional Information (Detail) - $ / shares	3 Months Ended
Mar. 31, 2021	Mar. 31, 2020
Performance Based Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options awarded	140,000
Percentage of shares vested on each anniversary of the grant date	33.00%
Vesting period	3 years
Vesting period expiration date	10 years
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock options awarded		0
Unvested stock options forfeited	300,000	0
Restricted Stock
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares vested	20,437	0
Restricted Stock \| Key Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares granted	0	0
Restricted Stock \| Non Employee Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares granted	20,006	23,127
Weighted average fair value per share	$ 28.32	$ 29.19
Shares deferred for vesting	4,903	6,422
Restricted Stock Units \| Key Employees
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period		3 years
Number of shares granted	0	94,281
Weighted average fair value per share		$ 29.63
Shares vested		3,375
Stock options, vested and expected to vest		90,906
Restricted Stock Units \| Key Employees \| Share-based Payment Arrangement, Tranche 1
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of shares vested on each anniversary of the grant date		16.50%
Vesting date		Jan. 01, 2021
Restricted Stock Units \| Key Employees \| Share-based Compensation Award, Tranche 2
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of shares vested on each anniversary of the grant date		16.50%
Vesting date		Jan. 01, 2022
Restricted Stock Units \| Key Employees \| Share-based Compensation Award, Tranche 3
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of shares vested on each anniversary of the grant date		17.00%
Vesting date		Jan. 01, 2023
Restricted Stock Units \| Key Employees \| Vesting Schedule One
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of shares vested on each anniversary of the grant date		100.00%
Vesting date		Mar. 15, 2023
Percentage of stock award subject to vesting		50.00%

Percentage of Stock Award Subject to Vesting

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- Definition

Share based compensation arrangement by share based payment award, award vesting date.

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- Definition

Share based compensation arrangement by share based payment award equity instruments other than options deferred for vesting.

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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.

+ References

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- Definition

The number of grants made during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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- Definition

The weighted average fair value at grant date for nonvested equity-based awards issued during the period on other than stock (or unit) option plans (for example, phantom stock or unit plan, stock or unit appreciation rights plan, performance target plan).

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- Definition

The number of equity-based payment instruments, excluding stock (or unit) options, that vested during the reporting period.

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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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- Definition

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

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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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- Definition

Percentage of vesting of award under share-based payment arrangement.

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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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- Definition

Number of non-vested options forfeited.

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