CREDIT QUALITY ASSESSMENT (Credit Risk Rating Indicators for Each Segment of Commercial Loan Portfolio) (Detail) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 4,133,171	$ 3,927,808
Commercial
Financing Receivable Recorded Investment [Line Items]
Total loans	451,570	467,286
Commercial Portfolio Segment [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans		2,479,230
Commercial Portfolio Segment [Member] | Commercial
Financing Receivable Recorded Investment [Line Items]
Total loans		467,286
Commercial Portfolio Segment [Member] | Commercial Acquisition, Development and Construction
Financing Receivable Recorded Investment [Line Items]
Total loans		308,279
Commercial Portfolio Segment [Member] | Commercial Investor Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans		928,113
Commercial Portfolio Segment [Member] | Commercial Owner Occupied Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans		775,552
Commercial Portfolio Segment [Member] | Pass
Financing Receivable Recorded Investment [Line Items]
Total loans		2,426,773
Commercial Portfolio Segment [Member] | Pass | Commercial
Financing Receivable Recorded Investment [Line Items]
Total loans		442,725
Commercial Portfolio Segment [Member] | Pass | Commercial Acquisition, Development and Construction
Financing Receivable Recorded Investment [Line Items]
Total loans		308,142
Commercial Portfolio Segment [Member] | Pass | Commercial Investor Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans		917,255
Commercial Portfolio Segment [Member] | Pass | Commercial Owner Occupied Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans		758,651
Commercial Portfolio Segment [Member] | Special Mention
Financing Receivable Recorded Investment [Line Items]
Total loans		21,660
Commercial Portfolio Segment [Member] | Special Mention | Commercial
Financing Receivable Recorded Investment [Line Items]
Total loans		10,010
Commercial Portfolio Segment [Member] | Special Mention | Commercial Acquisition, Development and Construction
Financing Receivable Recorded Investment [Line Items]
Total loans		0
Commercial Portfolio Segment [Member] | Special Mention | Commercial Investor Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans		2,395
Commercial Portfolio Segment [Member] | Special Mention | Commercial Owner Occupied Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans		9,255
Commercial Portfolio Segment [Member] | Substandard
Financing Receivable Recorded Investment [Line Items]
Total loans		30,797
Commercial Portfolio Segment [Member] | Substandard | Commercial
Financing Receivable Recorded Investment [Line Items]
Total loans		14,551
Commercial Portfolio Segment [Member] | Substandard | Commercial Acquisition, Development and Construction
Financing Receivable Recorded Investment [Line Items]
Total loans		137
Commercial Portfolio Segment [Member] | Substandard | Commercial Investor Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans		8,463
Commercial Portfolio Segment [Member] | Substandard | Commercial Owner Occupied Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans		7,646
Commercial Portfolio Segment [Member] | Doubtful
Financing Receivable Recorded Investment [Line Items]
Total loans		0
Commercial Portfolio Segment [Member] | Doubtful | Commercial
Financing Receivable Recorded Investment [Line Items]
Total loans		0
Commercial Portfolio Segment [Member] | Doubtful | Commercial Acquisition, Development and Construction
Financing Receivable Recorded Investment [Line Items]
Total loans		0
Commercial Portfolio Segment [Member] | Doubtful | Commercial Investor Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans		0
Commercial Portfolio Segment [Member] | Doubtful | Commercial Owner Occupied Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans		0
Commercial Real Estate Portfolio Segment
Financing Receivable Recorded Investment [Line Items]
Total loans	2,633,446
Commercial Real Estate Portfolio Segment | Commercial
Financing Receivable Recorded Investment [Line Items]
Total loans	451,570
Commercial Real Estate Portfolio Segment | Commercial Acquisition, Development and Construction
Financing Receivable Recorded Investment [Line Items]
Total loans	314,259	308,279
Commercial Real Estate Portfolio Segment | Commercial Investor Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans	1,069,988	928,113
Commercial Real Estate Portfolio Segment | Commercial Owner Occupied Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans	797,629	$ 775,552
Commercial Real Estate Portfolio Segment | Pass
Financing Receivable Recorded Investment [Line Items]
Total loans	2,591,185
Commercial Real Estate Portfolio Segment | Pass | Commercial
Financing Receivable Recorded Investment [Line Items]
Total loans	432,870
Commercial Real Estate Portfolio Segment | Pass | Commercial Acquisition, Development and Construction
Financing Receivable Recorded Investment [Line Items]
Total loans	314,122
Commercial Real Estate Portfolio Segment | Pass | Commercial Investor Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans	1,060,362
Commercial Real Estate Portfolio Segment | Pass | Commercial Owner Occupied Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans	783,831
Commercial Real Estate Portfolio Segment | Special Mention
Financing Receivable Recorded Investment [Line Items]
Total loans	10,850
Commercial Real Estate Portfolio Segment | Special Mention | Commercial
Financing Receivable Recorded Investment [Line Items]
Total loans	2,848
Commercial Real Estate Portfolio Segment | Special Mention | Commercial Acquisition, Development and Construction
Financing Receivable Recorded Investment [Line Items]
Total loans	0
Commercial Real Estate Portfolio Segment | Special Mention | Commercial Investor Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans	2,357
Commercial Real Estate Portfolio Segment | Special Mention | Commercial Owner Occupied Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans	5,645
Commercial Real Estate Portfolio Segment | Substandard
Financing Receivable Recorded Investment [Line Items]
Total loans	31,411
Commercial Real Estate Portfolio Segment | Substandard | Commercial
Financing Receivable Recorded Investment [Line Items]
Total loans	15,852
Commercial Real Estate Portfolio Segment | Substandard | Commercial Acquisition, Development and Construction
Financing Receivable Recorded Investment [Line Items]
Total loans	137
Commercial Real Estate Portfolio Segment | Substandard | Commercial Investor Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans	7,269
Commercial Real Estate Portfolio Segment | Substandard | Commercial Owner Occupied Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans	8,153
Commercial Real Estate Portfolio Segment | Doubtful
Financing Receivable Recorded Investment [Line Items]
Total loans	0
Commercial Real Estate Portfolio Segment | Doubtful | Commercial
Financing Receivable Recorded Investment [Line Items]
Total loans	0
Commercial Real Estate Portfolio Segment | Doubtful | Commercial Acquisition, Development and Construction
Financing Receivable Recorded Investment [Line Items]
Total loans	0
Commercial Real Estate Portfolio Segment | Doubtful | Commercial Investor Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans	0
Commercial Real Estate Portfolio Segment | Doubtful | Commercial Owner Occupied Real Estate
Financing Receivable Recorded Investment [Line Items]
Total loans	$ 0