Credit Quality Assessment (Credit Quality of Loan Portfolio) (Detail) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	$ 11,787	$ 13,642
Non-accrual loans and leases	30,031	28,530
Current loans	3,452,701	3,082,209
Total loans and leases	3,495,370	3,127,392
Receivables Acquired with Deteriorated Credit Quality [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans aquired with deteriorated credit quality	851	3,011
Commercial
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	523	1,754
Non-accrual loans and leases	3,696	3,184
Current loans	461,002	384,605
Total loans and leases	465,765	390,781
Commercial | Receivables Acquired with Deteriorated Credit Quality [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans aquired with deteriorated credit quality	544	1,238
Leases
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	0	11
Non-accrual loans and leases	0	0
Current loans	0	43
Total loans and leases	0	54
Leases | Receivables Acquired with Deteriorated Credit Quality [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans aquired with deteriorated credit quality	0	0
Consumer
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	2,192	976
Non-accrual loans and leases	2,193	1,668
Current loans	446,490	422,908
Total loans and leases	450,875	425,552
Consumer | Receivables Acquired with Deteriorated Credit Quality [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans aquired with deteriorated credit quality	0	0
Commercial Real Estate Portfolio Segment | Commercial Acquisition, Development and Construction
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	0	320
Non-accrual loans and leases	194	2,464
Current loans	255,786	202,340
Total loans and leases	255,980	205,124
Commercial Real Estate Portfolio Segment | Commercial Acquisition, Development and Construction | Receivables Acquired with Deteriorated Credit Quality [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans aquired with deteriorated credit quality	0	0
Commercial Real Estate Portfolio Segment | Commercial Investor Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	2,816	3,867
Non-accrual loans and leases	8,368	8,156
Current loans	707,900	628,170
Total loans and leases	719,084	640,193
Commercial Real Estate Portfolio Segment | Commercial Investor Real Estate | Receivables Acquired with Deteriorated Credit Quality [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans aquired with deteriorated credit quality	0	0
Commercial Real Estate Portfolio Segment | Commercial Owner Occupied Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	2,668	2,814
Non-accrual loans and leases	6,340	8,941
Current loans	668,712	597,533
Total loans and leases	678,027	611,061
Commercial Real Estate Portfolio Segment | Commercial Owner Occupied Real Estate | Receivables Acquired with Deteriorated Credit Quality [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans aquired with deteriorated credit quality	307	1,773
Residential Real Estate Portfolio Segment | Residential Mortgage
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	3,588	3,900
Non-accrual loans and leases	8,822	3,012
Current loans	783,948	710,974
Total loans and leases	796,358	717,886
Residential Real Estate Portfolio Segment | Residential Mortgage | Receivables Acquired with Deteriorated Credit Quality [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans aquired with deteriorated credit quality	0	0
Residential Real Estate Portfolio Segment | Residential Construction
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	0	0
Non-accrual loans and leases	418	1,105
Current loans	128,863	135,636
Total loans and leases	129,281	136,741
Residential Real Estate Portfolio Segment | Residential Construction | Receivables Acquired with Deteriorated Credit Quality [Member]
Financing Receivable Recorded Investment Past Due [Line Items]
Loans aquired with deteriorated credit quality	0	0
31-60 days
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	6,798	9,663
31-60 days | Commercial
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	119	759
31-60 days | Leases
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	0	11
31-60 days | Consumer
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	1,642	797
31-60 days | Commercial Real Estate Portfolio Segment | Commercial Acquisition, Development and Construction
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	0	0
31-60 days | Commercial Real Estate Portfolio Segment | Commercial Investor Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	616	2,374
31-60 days | Commercial Real Estate Portfolio Segment | Commercial Owner Occupied Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	1,819	2,658
31-60 days | Residential Real Estate Portfolio Segment | Residential Mortgage
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	2,602	3,064
31-60 days | Residential Real Estate Portfolio Segment | Residential Construction
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	0	0
61-90 days
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	4,989	3,979
61-90 days | Commercial
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	404	995
61-90 days | Leases
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	0	0
61-90 days | Consumer
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	550	179
61-90 days | Commercial Real Estate Portfolio Segment | Commercial Acquisition, Development and Construction
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	0	320
61-90 days | Commercial Real Estate Portfolio Segment | Commercial Investor Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	2,200	1,493
61-90 days | Commercial Real Estate Portfolio Segment | Commercial Owner Occupied Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	849	156
61-90 days | Residential Real Estate Portfolio Segment | Residential Mortgage
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	986	836
61-90 days | Residential Real Estate Portfolio Segment | Residential Construction
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	0	0
> 90 days
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	0	0
> 90 days | Commercial
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	0	0
> 90 days | Leases
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	0	0
> 90 days | Consumer
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	0	0
> 90 days | Commercial Real Estate Portfolio Segment | Commercial Acquisition, Development and Construction
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	0	0
> 90 days | Commercial Real Estate Portfolio Segment | Commercial Investor Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	0	0
> 90 days | Commercial Real Estate Portfolio Segment | Commercial Owner Occupied Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	0	0
> 90 days | Residential Real Estate Portfolio Segment | Residential Mortgage
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	0	0
> 90 days | Residential Real Estate Portfolio Segment | Residential Construction
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	$ 0	$ 0