CREDIT QUALITY ASSESSMENT (Credit Risk Rating Indicators for Each Segment of Commercial Loan Portfolio) (Detail) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 3,992,996	$ 3,927,808
Commercial
Financing Receivable Recorded Investment [Line Items]
Total loans	457,216	467,286
Commercial Portfolio Segment [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans	2,518,419	2,479,230
Commercial Portfolio Segment [Member] | Commercial
Financing Receivable Recorded Investment [Line Items]
Total loans	457,216	467,286
Commercial Portfolio Segment [Member] | Commercial Acquisition, Development and Construction
Financing Receivable Recorded Investment [Line Items]
Total loans	309,350	308,279
Commercial Portfolio Segment [Member] | Commercial Investor Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans	979,410	928,113
Commercial Portfolio Segment [Member] | Commercial Owner Occupied Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans	772,443	775,552
Commercial Portfolio Segment [Member] | Pass
Financing Receivable Recorded Investment [Line Items]
Total loans	2,475,763	2,426,773
Commercial Portfolio Segment [Member] | Pass | Commercial
Financing Receivable Recorded Investment [Line Items]
Total loans	439,936	442,725
Commercial Portfolio Segment [Member] | Pass | Commercial Acquisition, Development and Construction
Financing Receivable Recorded Investment [Line Items]
Total loans	309,213	308,142
Commercial Portfolio Segment [Member] | Pass | Commercial Investor Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans	968,724	917,255
Commercial Portfolio Segment [Member] | Pass | Commercial Owner Occupied Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans	757,890	758,651
Commercial Portfolio Segment [Member] | Special Mention
Financing Receivable Recorded Investment [Line Items]
Total loans	12,588	21,660
Commercial Portfolio Segment [Member] | Special Mention | Commercial
Financing Receivable Recorded Investment [Line Items]
Total loans	3,705	10,010
Commercial Portfolio Segment [Member] | Special Mention | Commercial Acquisition, Development and Construction
Financing Receivable Recorded Investment [Line Items]
Total loans	0	0
Commercial Portfolio Segment [Member] | Special Mention | Commercial Investor Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans	2,373	2,395
Commercial Portfolio Segment [Member] | Special Mention | Commercial Owner Occupied Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans	6,510	9,255
Commercial Portfolio Segment [Member] | Substandard
Financing Receivable Recorded Investment [Line Items]
Total loans	30,068	30,797
Commercial Portfolio Segment [Member] | Substandard | Commercial
Financing Receivable Recorded Investment [Line Items]
Total loans	13,575	14,551
Commercial Portfolio Segment [Member] | Substandard | Commercial Acquisition, Development and Construction
Financing Receivable Recorded Investment [Line Items]
Total loans	137	137
Commercial Portfolio Segment [Member] | Substandard | Commercial Investor Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans	8,313	8,463
Commercial Portfolio Segment [Member] | Substandard | Commercial Owner Occupied Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans	8,043	7,646
Commercial Portfolio Segment [Member] | Doubtful
Financing Receivable Recorded Investment [Line Items]
Total loans	0	0
Commercial Portfolio Segment [Member] | Doubtful | Commercial
Financing Receivable Recorded Investment [Line Items]
Total loans	0	0
Commercial Portfolio Segment [Member] | Doubtful | Commercial Acquisition, Development and Construction
Financing Receivable Recorded Investment [Line Items]
Total loans	0	0
Commercial Portfolio Segment [Member] | Doubtful | Commercial Investor Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans	0	0
Commercial Portfolio Segment [Member] | Doubtful | Commercial Owner Occupied Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans	0	0
Commercial Real Estate Portfolio Segment | Commercial Acquisition, Development and Construction
Financing Receivable Recorded Investment [Line Items]
Total loans	309,350	308,279
Commercial Real Estate Portfolio Segment | Commercial Investor Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans	979,410	928,113
Commercial Real Estate Portfolio Segment | Commercial Owner Occupied Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 772,443	$ 775,552