Credit Quality Assessment (Credit Quality of Loan Portfolio by Segment) (Detail) - USD ($) $ in Thousands	Jun. 30, 2015	Dec. 31, 2014
Financing Receivable Recorded Investment [Line Items]
Non-accrual loans and leases	$ 31,699	$ 28,530
Loans and leases 90 days past due	9	0
Restructured loans and leases	5,620	5,497
Total non-performing loans and leases	37,328	34,027
Other real estate owned	4,514	3,195
Total non-performing assets	41,842	37,222
Commercial
Financing Receivable Recorded Investment [Line Items]
Non-accrual loans and leases	3,285	3,184
Loans and leases 90 days past due	0	0
Restructured loans and leases	896	710
Total non-performing loans and leases	4,181	3,894
Other real estate owned	39	39
Total non-performing assets	4,220	3,933
Leases
Financing Receivable Recorded Investment [Line Items]
Non-accrual loans and leases	0	0
Loans and leases 90 days past due	2	0
Restructured loans and leases	0	0
Total non-performing loans and leases	2	0
Other real estate owned	0	0
Total non-performing assets	2	0
Consumer
Financing Receivable Recorded Investment [Line Items]
Non-accrual loans and leases	1,214	1,668
Loans and leases 90 days past due	7	0
Restructured loans and leases	0	0
Total non-performing loans and leases	1,221	1,668
Other real estate owned	690	0
Total non-performing assets	1,911	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	789	365
Total non-performing assets	983	2,829
Commercial Real Estate Portfolio Segment | Commercial Investor Real Estate
Financing Receivable Recorded Investment [Line Items]
Non-accrual loans and leases	10,023	8,156
Loans and leases 90 days past due	0	0
Restructured loans and leases	2,103	2,123
Total non-performing loans and leases	12,126	10,279
Other real estate owned	0	0
Total non-performing assets	12,126	10,279
Commercial Real Estate Portfolio Segment | Commercial Owner Occupied Real Estate
Financing Receivable Recorded Investment [Line Items]
Non-accrual loans and leases	8,423	8,941
Loans and leases 90 days past due	0	0
Restructured loans and leases	0	0
Total non-performing loans and leases	8,423	8,941
Other real estate owned	0	0
Total non-performing assets	8,423	8,941
Residential Real Estate Portfolio Segment | Residential Mortgage
Financing Receivable Recorded Investment [Line Items]
Non-accrual loans and leases	7,780	3,012
Loans and leases 90 days past due	0	0
Restructured loans and leases	2,621	2,664
Total non-performing loans and leases	10,401	5,676
Other real estate owned	1,613	1,408
Total non-performing assets	12,014	7,084
Residential Real Estate Portfolio Segment | Residential Construction
Financing Receivable Recorded Investment [Line Items]
Non-accrual loans and leases	780	1,105
Loans and leases 90 days past due	0	0
Restructured loans and leases	0	0
Total non-performing loans and leases	780	1,105
Other real estate owned	1,383	1,383
Total non-performing assets	$ 2,163	$ 2,488