CREDIT QUALITY ASSESSMENT (Credit Quality of Loan Portfolio) (Detail) - USD ($) $ in Thousands	Sep. 30, 2017	Dec. 31, 2016
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	$ 13,856	$ 14,762
Non-accrual loans	27,508	29,211
Current loans	4,152,754	3,883,835
Total loans	4,194,118	3,927,808
Commercial
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	2,218	1,335
Non-accrual loans	6,091	5,833
Current loans	443,358	460,118
Total loans	451,667	467,286
Consumer
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	1,477	1,912
Non-accrual loans	3,152	2,859
Current loans	451,766	451,886
Total loans	456,395	456,657
Commercial Real Estate Portfolio Segment | Commercial Acquisition, Development and Construction
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	0	896
Non-accrual loans	137	137
Current loans	295,085	307,246
Total loans	295,222	308,279
Commercial Real Estate Portfolio Segment | Commercial Investor Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	0	2,056
Non-accrual loans	5,589	8,107
Current loans	1,099,080	917,950
Total loans	1,104,669	928,113
Commercial Real Estate Portfolio Segment | Commercial Owner Occupied Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	1,137	2,223
Non-accrual loans	5,012	4,823
Current loans	825,312	768,506
Total loans	831,461	775,552
Residential Real Estate Portfolio Segment | Residential Mortgage
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	9,024	6,340
Non-accrual loans	7,345	7,257
Current loans	866,521	828,095
Total loans	882,890	841,692
Residential Real Estate Portfolio Segment | Residential Construction
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	0	0
Non-accrual loans	182	195
Current loans	171,632	150,034
Total loans	171,814	150,229
31-60 days
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	8,026	8,665
31-60 days | Commercial
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	1,442	663
31-60 days | Consumer
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	820	808
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	896
31-60 days | Commercial Real Estate Portfolio Segment | Commercial Investor Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	0	850
31-60 days | Commercial Real Estate Portfolio Segment | Commercial Owner Occupied Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	1,137	1,479
31-60 days | Residential Real Estate Portfolio Segment | Residential Mortgage
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	4,627	3,969
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	5,604	5,865
61-90 days | Commercial
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	776	672
61-90 days | Consumer
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	656	1,104
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	0
61-90 days | Commercial Real Estate Portfolio Segment | Commercial Investor Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	0	1,206
61-90 days | Commercial Real Estate Portfolio Segment | Commercial Owner Occupied Real Estate
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	0	744
61-90 days | Residential Real Estate Portfolio Segment | Residential Mortgage
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	4,172	2,139
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	226	232
> 90 days | Commercial
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	1	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	225	232
> 90 days | Residential Real Estate Portfolio Segment | Residential Construction
Financing Receivable Recorded Investment Past Due [Line Items]
Total past due	$ 0	$ 0