Credit Quality Assessment (Credit Quality of Loan Portfolio by Segment) (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Financing Receivable Recorded Investment [Line Items]
Non-accrual loans and leases	$ 30,031	$ 28,530
Loans and leases 90 days past due	0	0
Restructured loans and leases	4,467	5,497
Total non-performing loans and leases	34,498	34,027
Other real estate owned	2,742	3,195
Total non-performing assets	37,240	37,222
Commercial
Financing Receivable Recorded Investment [Line Items]
Non-accrual loans and leases	3,696	3,184
Loans and leases 90 days past due	0	0
Restructured loans and leases	1,577	710
Total non-performing loans and leases	5,273	3,894
Other real estate owned	39	39
Total non-performing assets	5,312	3,933
Leases
Financing Receivable Recorded Investment [Line Items]
Non-accrual loans and leases	0	0
Loans and leases 90 days past due	0	0
Restructured loans and leases	0	0
Total non-performing loans and leases	0	0
Other real estate owned	0	0
Total non-performing assets	0	0
Consumer
Financing Receivable Recorded Investment [Line Items]
Non-accrual loans and leases	2,193	1,668
Loans and leases 90 days past due	0	0
Restructured loans and leases	0	0
Total non-performing loans and leases	2,193	1,668
Other real estate owned	690	0
Total non-performing assets	2,883	1,668
Commercial Real Estate Portfolio Segment | Commercial Acquisition, Development and Construction
Financing Receivable Recorded Investment [Line Items]
Non-accrual loans and leases	194	2,464
Loans and leases 90 days past due	0	0
Restructured loans and leases	0	0
Total non-performing loans and leases	194	2,464
Other real estate owned	365	365
Total non-performing assets	559	2,829
Commercial Real Estate Portfolio Segment | Commercial Investor Real Estate
Financing Receivable Recorded Investment [Line Items]
Non-accrual loans and leases	8,368	8,156
Loans and leases 90 days past due	0	0
Restructured loans and leases	2,073	2,123
Total non-performing loans and leases	10,441	10,279
Other real estate owned	433	0
Total non-performing assets	10,874	10,279
Commercial Real Estate Portfolio Segment | Commercial Owner Occupied Real Estate
Financing Receivable Recorded Investment [Line Items]
Non-accrual loans and leases	6,340	8,941
Loans and leases 90 days past due	0	0
Restructured loans and leases	240	0
Total non-performing loans and leases	6,580	8,941
Other real estate owned	0	0
Total non-performing assets	6,580	8,941
Residential Real Estate Portfolio Segment | Residential Mortgage
Financing Receivable Recorded Investment [Line Items]
Non-accrual loans and leases	8,822	3,012
Loans and leases 90 days past due	0	0
Restructured loans and leases	577	2,664
Total non-performing loans and leases	9,399	5,676
Other real estate owned	1,215	1,408
Total non-performing assets	10,614	7,084
Residential Real Estate Portfolio Segment | Residential Construction
Financing Receivable Recorded Investment [Line Items]
Non-accrual loans and leases	418	1,105
Loans and leases 90 days past due	0	0
Restructured loans and leases	0	0
Total non-performing loans and leases	418	1,105
Other real estate owned	0	1,383
Total non-performing assets	$ 418	$ 2,488