Loans and Leases - Summary of Originated Troubled Debt Restructurings by Class of Loans and Leases, Payment Default (Detail) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2016 USD ($) Contract	Jun. 30, 2015 USD ($) Contract	Jun. 30, 2016 USD ($) Contract	Jun. 30, 2015 USD ($) Contract
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract		38	34	69	69
Recorded Investment | $	[1]	$ 340	$ 446	$ 512	$ 681
Commercial and Industrial [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract			1		1
Recorded Investment | $	[1]		$ 229		$ 229
Total Commercial Loans and Leases [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract			1		1
Recorded Investment | $	[1]		$ 229		$ 229
Direct Installment [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract		32	27	57	58
Recorded Investment | $	[1]	$ 135	$ 96	$ 246	$ 182
Residential Mortgages [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract		3	3	4	4
Recorded Investment | $	[1]	$ 142	$ 114	$ 193	$ 171
Indirect Installment [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract		2	3	6	5
Recorded Investment | $	[1]	$ 8	$ 7	$ 8	$ 7
Consumer Lines of Credit [Member]
Financing Receivable, Modifications [Line Items]
Number of Contracts | Contract		1		2	1
Recorded Investment | $	[1]	$ 55		$ 65	$ 92

[1] The recorded investment is as of period end.