Loans and Allowance for Loan Losses - Schedule of Loans by Class Modified as Troubled Debt Restructuring (Detail) $ in Thousands	3 Months Ended
Mar. 31, 2019 USD ($) SecurityLoan	Mar. 31, 2018 USD ($) SecurityLoan
Financing Receivable, Modifications [Line Items]
Number of Loans \| SecurityLoan	4	3
Pre-modification Outstanding Recorded Investment	$ 5,510	$ 1,537
Post-modification Outstanding Recorded Investment	$ 5,510	$ 1,537
Commercial Loan [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans \| SecurityLoan	3	1
Pre-modification Outstanding Recorded Investment	$ 2,407	$ 539
Post-modification Outstanding Recorded Investment	$ 2,407	$ 539
Other [Member] \| Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans \| SecurityLoan	1	1
Pre-modification Outstanding Recorded Investment	$ 3,103	$ 566
Post-modification Outstanding Recorded Investment	$ 3,103	$ 566
Consumer - Other [Member]
Financing Receivable, Modifications [Line Items]
Number of Loans \| SecurityLoan		1
Pre-modification Outstanding Recorded Investment		$ 432
Post-modification Outstanding Recorded Investment		$ 432

The number of loans included in the loan portfolio.

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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

Post-modification amount of investment in financing receivables modified by troubled debt restructurings.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953676-111524

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- Definition

Pre-modification amount of investment in financing receivables modified by troubled debt restructurings.

+ References

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