Loans and Leases - Additional Allowance for Credit Losses Relating to Acquired Loans (Detail) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2016	Dec. 31, 2015
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses	$ 5,650	$ 6,727
Commercial Real Estate [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses	2,775	3,073
Commercial and Industrial [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses	600	695
Total Commercial Loans and Leases [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses	3,375	3,768
Direct Installment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses	1,183	1,557
Residential Mortgages [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses	582	659
Indirect Installment [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses	221	221
Consumer Lines of Credit [Member]
Financing Receivable, Allowance for Credit Losses [Line Items]
Allowance for loan losses	$ 289	$ 522