Term of life insurance policy.

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- Definition

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.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section 45
-Paragraph 4
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=121566466&loc=d3e6812-107765

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
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-URI http://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682

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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.

+ References

No definition available.

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- Definition

Amount of benefit for defined benefit plan expected to be paid in five fiscal years after fifth fiscal year following current fiscal year.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (f)
-URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920

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- Definition

Amount of benefit for defined benefit plan expected to be paid in next fiscal year following current fiscal year.

+ References

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- Definition

Amount of benefit for defined benefit plan expected to be paid in fifth fiscal year following current fiscal year.

+ References

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- Definition

Amount of benefit for defined benefit plan expected to be paid in fourth fiscal year following current fiscal year.

+ References

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- Definition

Amount of benefit for defined benefit plan expected to be paid in third fiscal year following current fiscal year.

+ References

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- Definition

Amount of benefit for defined benefit plan expected to be paid in second fiscal year following current fiscal year.

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- Definition

Amount of increase (decrease) in benefit obligation of defined benefit plan from change in terms of existing plan or initiation of new plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (a)(7)
-URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920

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- Definition

Percentage of target investment allocation to total plan assets. Includes, but is not limited to, percentage on weighted-average basis if more than one plan.

+ References

Reference 1: http://www.xbrl.org/2003/role/exampleRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 55
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=118257860&loc=d3e4179-114921

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-Publisher FASB
-Name Accounting Standards Codification
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-SubTopic 20
-Section 50
-Paragraph 1
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-URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920

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- Definition

Amount of discretionary contributions made by an employer to a defined contribution plan.

+ References

No definition available.

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- Definition

Percentage of employees' gross pay for which the employer contributes a matching contribution to a defined contribution plan.

+ References

No definition available.

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- Definition

Maximum amount the employee may contribute to a defined contribution plan.

+ References

No definition available.

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- Definition

Maximum percentage of employee gross pay the employee may contribute to a defined contribution plan.

+ References

No definition available.

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- Definition

The expense in the period incurred with respect to protection provided by insurance entities against risks other than risks associated with production (which are allocated to cost of sales).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.4)
-URI http://asc.fasb.org/extlink&oid=120395209&loc=SL114868664-224227

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Employee Benefits - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Benefits expected to be paid in 2021	$ 2,008,000
Benefits expected to be paid in 2022	2,188,000
Benefits expected to be paid in 2023	2,322,000
Benefits expected to be paid in 2024	2,521,000
Benefits expected to be paid in 2025	2,707,000
Aggregate benefits expected to paid	$ 16,087,000
Voluntary contribution of employees	33.30%
Contributions matched by compensation contribution	6.00%
Voluntary contribution of employees, amount	$ 533,000	$ 458,000	$ 454,000
Discretionary bonus expense	2,529,000	2,364,000	2,355,000
Expenses related to the insurance agreement	464,000	456,000	$ 420,000
Term Life Insurance [Member]
Defined Benefit Plan Disclosure [Line Items]
Aggregate insurance amount	$ 15,000,000
term of insurance policy	ten years
Expenses related to the insurance agreement	$ 155,000
Change in Assumptions for Pension Plans [Member]
Defined Benefit Plan Disclosure [Line Items]
Decrease in the projected benefit obligations		$ 6,800,000
Supplemental Insurance/ Retirement Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Benefits expected to be paid in 2021	2,570,000
Benefits expected to be paid in 2022	2,507,000
Benefits expected to be paid in 2023	2,439,000
Benefits expected to be paid in 2024	2,595,000
Benefits expected to be paid in 2025	3,102,000
Aggregate benefits expected to paid	$ 17,913,000
Equity Securities [Member] \| Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Allocation mix for the common and collective trust portfolio	47.00%
Equity Securities [Member] \| Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Allocation mix for the common and collective trust portfolio	61.00%
Fixed Income Funds [Member] \| Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Allocation mix for the common and collective trust portfolio	24.00%
Fixed Income Funds [Member] \| Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Allocation mix for the common and collective trust portfolio	38.00%
Hedge Funds [Member] \| Minimum [Member]
Defined Benefit Plan Disclosure [Line Items]
Allocation mix for the common and collective trust portfolio	9.00%
Hedge Funds [Member] \| Maximum [Member]
Defined Benefit Plan Disclosure [Line Items]
Allocation mix for the common and collective trust portfolio	15.00%