Deferred income tax expense benefit arising from share based compensation.

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- Definition

Shareholder return award performance measurement period.

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- Definition

Stock option achieving maximum threshold.

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Stock option achieving minimum threshold.

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- Definition

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

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- Definition

Amount of cost not yet recognized for nonvested award under share-based payment arrangement.

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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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- Definition

Estimated period over which an employee is required to provide service in exchange for the equity-based payment award, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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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.

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- Definition

The number of non-vested equity-based payment instruments, excluding stock (or unit) options, that validly exist and are outstanding as of the balance sheet date.

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- Definition

Fair value of share-based awards for which the grantee gained the right by satisfying service and performance requirements, to receive or retain shares or units, other instruments, or cash.

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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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No definition available.

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- Definition

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

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No definition available.

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

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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.

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- Definition

Amount of accumulated difference between fair value of underlying shares on dates of exercise and exercise price on options exercised (or share units converted) into shares.

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- Definition

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

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No definition available.

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- Definition

Description of terms of award under share-based payment arrangement.

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- Definition

Intrinsic value of vested award under share-based payment arrangement. Excludes share and unit options.

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No definition available.

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Accounting for Stock Based Compensation - Additional Information (Detail) - USD ($) $ in Thousands			12 Months Ended
	May 21, 2020	May 19, 2017	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	May 16, 2013
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Performance based restricted stock units outstanding			34,906	34,920	136,566	282,100
Shareholder Return Award Performance Measurement Period			3 years
Unrecognized compensation cost related to non-vested options, restricted stock, restricted stock units and PSUs			$ 13,604	$ 13,168
Unrecognized share-based compensation cost recognition period			2 years
Share based compensation expense			$ 14,323	8,589	$ 12,177
Deferred tax benefit			$ 3,002	$ 1,573	$ 2,434
Granted, Shares			0	0	0
Total intrinsic value of options exercised			$ 5,317	$ 1,681	$ 5,061
Total fair value of restricted shares vested			$ 1,499	$ 3,697	$ 4,599
Performance Based Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Performance based restricted stock units outstanding			315,834
These awards vesting period			3 years
Stock option achieving minimum threshold			50.00%
Stock option achieving maximum threshold			200.00%
RSU
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Performance based restricted stock units outstanding			524,739	331,821	215,969
Total intrinsic value of restricted stock units vested			$ 2,214	$ 1,000	$ 0
Stock Appreciation Rights (SARs)
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Total intrinsic value of options exercised			$ 4,164	$ 1,588	$ 3,532
ROIC \| Performance Based Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Performance based restricted stock payment condition			one-half
TSR \| Performance Based Restricted Stock Units
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Performance based restricted stock payment condition			one-half
Employee and Consultants \| Minimum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation, requisite service period			3 years
Employee and Consultants \| Maximum
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation, requisite service period			4 years
Director
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Share based compensation, requisite service period			1 year
2013 Plan
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares authorized for grant			3,021,451
Number of shares authorized for grant							3,500,000
Number of increased shares available for grant	2,450,000	2,000,000
Equity Incentive Plan Twenty Eleven and Two Thousand and Six
Share Based Compensation Arrangement By Share Based Payment Award [Line Items]
Number of shares authorized for grant							0