Portfolio Quality Indicators (Detail) - USD ($) $ in Thousands	Sep. 30, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment [Line Items]
Commercial	$ 89,844	$ 81,327
Commercial Real Estate	215,793	198,936
Residential Real Estate	76,668	75,853
Installment	10,877	12,473
Total	393,182	368,589
Pass Grade
Financing Receivable, Recorded Investment [Line Items]
Commercial	89,754	78,652
Commercial Real Estate	214,254	195,063
Residential Real Estate	76,668	75,853
Installment	10,782	12,167
Total	391,458	361,735
Special Mention
Financing Receivable, Recorded Investment [Line Items]
Commercial	0	20
Commercial Real Estate	464	3,066
Residential Real Estate	0	0
Installment	0	0
Total	464	3,086
Substandard
Financing Receivable, Recorded Investment [Line Items]
Commercial	90	2,655
Commercial Real Estate	1,075	807
Residential Real Estate	0	0
Installment	95	306
Total	1,260	3,768
Doubtful
Financing Receivable, Recorded Investment [Line Items]
Commercial	0	0
Commercial Real Estate	0	0
Residential Real Estate	0	0
Installment	0	0
Total	$ 0	$ 0

Loans and leases receivable, residential, real estate.

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Amount, before allowance and fees, of loans and leases receivable. Excludes loans and leases covered under loss sharing agreements.

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Amount before allowance of installment and revolving loans issued to individuals, including, but not limited to credit card, automobile, boat, student, durable home appliance loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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Amount before allowance of commercial loans issued to businesses to acquire, develop, construct, improve, or refinance land or building. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans covered under loss sharing agreements.

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