Loans and Allowance for Loan Losses - Additional Information (Detail)	3 Months Ended
Mar. 31, 2019 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2018 USD ($)
Financing Receivable, Allowance for Credit Losses [Line Items]
Proceeds from sales of loans held for sale	$ 21,258,000	$ 9,664,000
Non- Accrual Loans	63,270,000		$ 43,018,000
Restructured loans	20,700,000		21,100,000
Total Past Due	87,692,000		65,850,000
Commitments to lend to borrowers with loan modifications classified as TDR's	$ 0	$ 0
Number of Contracts	0	0
Default payment of troubled restructuring, commercial real estate loan within 12months following restructure date	$ 0	$ 0
Revolving Commercial Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Number of days past due to consider loan as a loss and charged off	90 days
Closed-End Retail Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Number of days past due to consider loan as a loss and charged off	120 days
Open-End Retail Loans [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Number of days past due to consider loan as a loss and charged off	180 days
Greater than 90 days Past Due and Accruing [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Total Past Due	$ 1,874,000		$ 6,009,000

Period past due to charge off loan.

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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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Number of financing receivables that have been modified by troubled debt restructurings.

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-Name Accounting Standards Codification
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The amount of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings.

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Amount of investment related to financing receivables modified by troubled debt restructurings within the previous 12 months, for which there was a payment default.

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Recorded investment in financing receivables that are on nonaccrual status as of the balance sheet date.

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Recorded Investment in financing receivables that are past due at the balance sheet date.

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Reflects the unfunded portion of contractual agreements to lend funds to borrowers for loans whose terms have been modified by troubled debt restructuring.

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- Definition

The cash inflow resulting from the sale of loans classified as held-for-sale, including proceeds from loans sold through mortgage securitization.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher FASB
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