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Employee Benefit Plans - Narrative (Detail) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
	Jul. 01, 2018	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020	Dec. 31, 2020
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Deferred compensation plan liability		$ 35,715		$ 35,715		$ 26,390
Cash surrender value of policies		36,306		36,306		$ 26,832
Change in fair value of plan assets		(84)	$ 1,204	2,658	$ 1,972
Change in fair value of deferred compensation liabilities		$ (159)	$ 1,085	$ 2,526	$ 1,942
U.S.
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Vesting percentage of participants (in percentage)	100.00%
Employer discretionary vesting period	2 years
Earnings receivable minimum term	2 years
Earnings receivable lump sum or annual installment maximum terms	15 years
One-Year Anniversary of Approval of Contribution | U.S.
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Employer discretionary vesting percentage (in percentage)	50.00%
Two-Year Anniversary of Approval of Contribution | U.S.
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Employer discretionary vesting percentage (in percentage)	50.00%
Minimum | U.S.
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Individual qualifying base compensation (in percentage)	1.00%
Individual qualifying bonus compensation (in percentage)	1.00%
Maximum | U.S.
Deferred Compensation Arrangement with Individual, Excluding Share-based Payments and Postretirement Benefits [Line Items]
Individual qualifying base compensation (in percentage)	80.00%
Individual qualifying bonus compensation (in percentage)	100.00%

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Carrying amount as of the balance sheet date of amounts which could be received based on the terms of the insurance contract upon surrendering life policies owned by the entity.

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-Publisher FASB
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Commitment made to pay deferred cash remuneration expressed as a percentage of the individual's base salary.

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Maximum term of the deferred compensation arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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Minimum period the individual is required to perform services to be fully vested under the deferred compensation arrangement, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

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