CREDIT QUALITY ASSESSMENT (Activity in Allowance for Loan and Lease Losses by Respective Loan Portfolio Segment) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	Dec. 31, 2016
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of year			$ 44,067	$ 40,895	$ 40,895
Provision (credit)	$ 1,322	$ 2,957	1,516	4,193	5,546
Charge-offs			(824)	(2,272)	(3,134)
Recoveries			320	568	760
Net charge-offs			(504)	(1,704)	(2,374)
Balance at period end	45,079	$ 43,384	45,079	43,384	44,067
Total loans and leases	$ 4,133,171		$ 4,133,171		$ 3,927,808
Allowance for loans and leases to total loans and leases ratio	1.09%		1.09%		1.12%
Balance of loans specifically evaluated for impairment	$ 24,603		$ 24,603		$ 24,092
Allowance for loans specifically evaluated for impairment	$ 5,772		$ 5,772		$ 4,825
Specific allowance to specific loans ratio	23.46%		23.46%		20.03%
Balance of loans collectively evaluated	$ 4,108,568		$ 4,108,568		$ 3,903,716
Allowance for loans collectively evaluated	39,307		$ 39,307		$ 39,242
Collective allowance to collective loans ratio			0.96%		1.01%
Commercial
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of year			$ 7,539	6,529	$ 6,529
Provision (credit)			1,877		1,563
Charge-offs			(411)		(597)
Recoveries			44		44
Net charge-offs			(367)		(553)
Balance at period end	9,049		9,049		7,539
Total loans and leases	$ 451,570		$ 451,570		$ 467,286
Allowance for loans and leases to total loans and leases ratio	2.00%		2.00%		1.61%
Balance of loans specifically evaluated for impairment	$ 8,977		$ 8,977		$ 7,018
Allowance for loans specifically evaluated for impairment	$ 4,740		$ 4,740		$ 2,604
Specific allowance to specific loans ratio	52.80%		52.80%		37.10%
Balance of loans collectively evaluated	$ 442,593		$ 442,593		$ 460,268
Allowance for loans collectively evaluated	4,309		$ 4,309		$ 4,935
Collective allowance to collective loans ratio			0.97%		1.07%
Consumer
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of year			$ 2,828	3,456	$ 3,456
Provision (credit)			464		112
Charge-offs			(404)		(888)
Recoveries			48		148
Net charge-offs			(356)		(740)
Balance at period end	2,936		2,936		2,828
Total loans and leases	$ 458,058		$ 458,058		$ 456,657
Allowance for loans and leases to total loans and leases ratio	0.64%		0.64%		0.62%
Balance of loans collectively evaluated	$ 458,058		$ 458,058		$ 456,657
Allowance for loans collectively evaluated	2,936		$ 2,936		$ 2,828
Collective allowance to collective loans ratio			0.64%		0.62%
Commercial Real Estate Portfolio Segment
Financing Receivable Allowance For Credit Losses [Line Items]
Total loans and leases	2,633,446		$ 2,633,446
Commercial Real Estate Portfolio Segment | Commercial
Financing Receivable Allowance For Credit Losses [Line Items]
Total loans and leases	451,570		451,570
Commercial Real Estate Portfolio Segment | Commercial Acquisition, Development and Construction
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of year			4,652	4,691	$ 4,691
Provision (credit)			(630)		(31)
Charge-offs			0		(48)
Recoveries			103		40
Net charge-offs			103		(8)
Balance at period end	4,125		4,125		4,652
Total loans and leases	$ 314,259		$ 314,259		$ 308,279
Allowance for loans and leases to total loans and leases ratio	1.31%		1.31%		1.51%
Balance of loans specifically evaluated for impairment	$ 137		$ 137		$ 137
Allowance for loans specifically evaluated for impairment	$ 0		$ 0		$ 0
Specific allowance to specific loans ratio	0.00%		0.00%		0.00%
Balance of loans collectively evaluated	$ 314,122		$ 314,122		$ 308,142
Allowance for loans collectively evaluated	4,125		$ 4,125		$ 4,652
Collective allowance to collective loans ratio			1.31%		1.51%
Commercial Real Estate Portfolio Segment | Commercial Investor Real Estate
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of year			$ 12,939	10,440	$ 10,440
Provision (credit)			150		2,563
Charge-offs			0		(197)
Recoveries			83		133
Net charge-offs			83		(64)
Balance at period end	13,172		13,172		12,939
Total loans and leases	$ 1,069,988		$ 1,069,988		$ 928,113
Allowance for loans and leases to total loans and leases ratio	1.23%		1.23%		1.39%
Balance of loans specifically evaluated for impairment	$ 6,934		$ 6,934		$ 8,107
Allowance for loans specifically evaluated for impairment	$ 736		$ 736		$ 1,736
Specific allowance to specific loans ratio	10.61%		10.61%		21.41%
Balance of loans collectively evaluated	$ 1,063,054		$ 1,063,054		$ 920,006
Allowance for loans collectively evaluated	12,436		$ 12,436		$ 11,203
Collective allowance to collective loans ratio			1.17%		1.22%
Commercial Real Estate Portfolio Segment | Commercial Owner Occupied Real Estate
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of year			$ 7,885	7,984	$ 7,984
Provision (credit)			(1,204)		(104)
Charge-offs			0		0
Recoveries			0		5
Net charge-offs			0		5
Balance at period end	6,681		6,681		7,885
Total loans and leases	$ 797,629		$ 797,629		$ 775,552
Allowance for loans and leases to total loans and leases ratio	0.84%		0.84%		1.02%
Balance of loans specifically evaluated for impairment	$ 5,667		$ 5,667		$ 5,567
Allowance for loans specifically evaluated for impairment	$ 296		$ 296		$ 485
Specific allowance to specific loans ratio	5.22%		5.22%		8.71%
Balance of loans collectively evaluated	$ 791,962		$ 791,962		$ 769,985
Allowance for loans collectively evaluated	6,385		$ 6,385		$ 7,400
Collective allowance to collective loans ratio			0.81%		0.96%
Residential Real Estate Portfolio Segment | Residential Mortgage
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of year			$ 7,261	6,901	$ 6,901
Provision (credit)			725		1,406
Charge-offs			(9)		(1,404)
Recoveries			28		358
Net charge-offs			19		(1,046)
Balance at period end	8,005		8,005		7,261
Total loans and leases	$ 871,766		$ 871,766		$ 841,692
Allowance for loans and leases to total loans and leases ratio	0.92%		0.92%		0.86%
Balance of loans specifically evaluated for impairment	$ 2,888		$ 2,888		$ 3,263
Allowance for loans specifically evaluated for impairment	0		0		0
Balance of loans collectively evaluated	868,878		868,878		838,429
Allowance for loans collectively evaluated	8,005		$ 8,005		$ 7,261
Collective allowance to collective loans ratio			0.92%		0.87%
Residential Real Estate Portfolio Segment | Residential Construction
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of year			$ 963	$ 894	$ 894
Provision (credit)			134		37
Charge-offs			0		0
Recoveries			14		32
Net charge-offs			14		32
Balance at period end	1,111		1,111		963
Total loans and leases	$ 169,901		$ 169,901		$ 150,229
Allowance for loans and leases to total loans and leases ratio	0.65%		0.65%		0.64%
Balance of loans specifically evaluated for impairment	$ 0		$ 0		$ 0
Allowance for loans specifically evaluated for impairment	0		0		0
Balance of loans collectively evaluated	169,901		169,901		150,229
Allowance for loans collectively evaluated	$ 1,111		$ 1,111		$ 963
Collective allowance to collective loans ratio			0.65%		0.64%