Loans - Restructured in Troubled Debt (Detail) $ in Thousands	3 Months Ended	6 Months Ended
Jun. 30, 2018 USD ($) loan	Jun. 30, 2017 loan	Jun. 30, 2018 USD ($) loan	Jun. 30, 2017 loan	Dec. 31, 2017 USD ($) loan
Financing Receivable, Modifications [Line Items]
Number of loans at a point in time \| loan	24		24		20
Number of loans, period of time \| loan	4	0	4	0
Loan Balance	$ 18,002		$ 18,002		$ 17,303
Specific Reserve	6,523		6,523		$ 5,689
Pre-Modification Outstanding Recorded Investment	1,091		1,091
Post-Modification Outstanding Recorded Investment	$ 1,091		$ 1,091
Commercial, Industrial, and Agricultural
Financing Receivable, Modifications [Line Items]
Number of loans at a point in time \| loan	11		11		11
Number of loans, period of time \| loan	0		0
Loan Balance	$ 4,872		$ 4,872		$ 5,213
Specific Reserve	257		257		$ 245
Pre-Modification Outstanding Recorded Investment	0		0
Post-Modification Outstanding Recorded Investment	$ 0		$ 0
Commercial mortgages
Financing Receivable, Modifications [Line Items]
Number of loans at a point in time \| loan	13		13		9
Number of loans, period of time \| loan	4		4
Loan Balance	$ 13,130		$ 13,130		$ 12,090
Specific Reserve	6,266		6,266		$ 5,444
Pre-Modification Outstanding Recorded Investment	1,091		1,091
Post-Modification Outstanding Recorded Investment	$ 1,091		$ 1,091
Residential Real Estate
Financing Receivable, Modifications [Line Items]
Number of loans at a point in time \| loan	0		0		0
Number of loans, period of time \| loan	0		0
Loan Balance	$ 0		$ 0		$ 0
Specific Reserve	0		0		$ 0
Pre-Modification Outstanding Recorded Investment	0		0
Post-Modification Outstanding Recorded Investment	$ 0		$ 0
Consumer
Financing Receivable, Modifications [Line Items]
Number of loans at a point in time \| loan	0		0		0
Number of loans, period of time \| loan	0		0
Loan Balance	$ 0		$ 0		$ 0
Specific Reserve	0		0		$ 0
Pre-Modification Outstanding Recorded Investment	0		0
Post-Modification Outstanding Recorded Investment	$ 0		$ 0
Credit Cards
Financing Receivable, Modifications [Line Items]
Number of loans at a point in time \| loan	0		0		0
Number of loans, period of time \| loan	0		0
Loan Balance	$ 0		$ 0		$ 0
Specific Reserve	0		0		$ 0
Pre-Modification Outstanding Recorded Investment	0		0
Post-Modification Outstanding Recorded Investment	$ 0		$ 0

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

+ References

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-Publisher FASB
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-SubTopic 10
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-Name Accounting Standards Codification
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