Employee Benefit Plans - Summary of Components Accumulated Other Comprehensive Loss (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Accumulated Other Comprehensive (Income) Loss, Defined Benefit Plan, after Tax [Abstract]
Net actuarial gain/(loss)	$ 940	$ 697	$ (831)
Net prior service cost	(22)	(8)	(9)
Deferred taxes	53	74	342
Accumulated other comprehensive gain/(loss), net of tax	$ 971	$ 763	$ (498)

Defined Benefit Plan, Accumulated Other Comprehensive Income Deferred Tax Benefit (Expense), After Tax

No definition available.

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- Definition

Amount, after tax, of accumulated other comprehensive (income) loss for defined benefit plan, that has not been recognized in net periodic benefit cost (credit).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 14A
-URI http://asc.fasb.org/extlink&oid=114867106&loc=SL7669686-108580

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-Publisher FASB
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-Section 45
-Paragraph 10A
-Subparagraph (i-k)
-URI http://asc.fasb.org/extlink&oid=114867106&loc=SL7669646-108580

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- References

No definition available.

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- Definition

Amount, after tax, of accumulated other comprehensive income (loss) for gain (loss) of defined benefit plan, that has not been recognized in net periodic benefit (cost) credit.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section 45
-Paragraph 14A
-URI http://asc.fasb.org/extlink&oid=114867106&loc=SL7669686-108580

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-Publisher FASB
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- Definition

Amount, after tax, of accumulated other comprehensive (income) loss for cost (credit) of benefit change attributable to participants' prior service from plan amendment or plan initiation of defined benefit plan, that has not been recognized in net periodic benefit cost (credit).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
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