CREDIT QUALITY ASSESSMENT (Activity in Allowance for Loan and Lease Losses by Respective Loan Portfolio Segment) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015	Dec. 31, 2015
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of year			$ 40,895	$ 37,802	$ 37,802
Provision (credit)	$ 781	$ 1,706	4,974	3,521	5,371
Charge-offs			(2,586)	(2,753)	(3,795)
Recoveries			659	1,091	1,517
Net charge-offs			(1,927)	(1,662)	(2,278)
Balance at period end	43,942	$ 39,661	43,942	39,661	40,895
Total loans and leases	$ 3,780,507		$ 3,780,507		$ 3,495,370
Allowance for loans and leases to total loans and leases ratio	1.16%		1.16%		1.17%
Balance of loans specifically evaluated for impairment	$ 24,297		$ 24,297		$ 28,927
Allowance for loans specifically evaluated for impairment	$ 3,652		$ 3,652		$ 3,375
Specific allowance to specific loans ratio	15.03%		15.03%		11.67%
Balance of loans collectively evaluated	$ 3,756,210		$ 3,756,210		$ 3,466,443
Allowance for loans collectively evaluated	40,290		$ 40,290		$ 37,520
Collective allowance to collective loans ratio			1.07%		1.08%
Commercial
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of year			$ 6,529	5,852	$ 5,852
Provision (credit)			635		508
Charge-offs			(289)		(306)
Recoveries			21		475
Net charge-offs			(268)		169
Balance at period end	6,896		6,896		6,529
Total loans and leases	$ 444,129		$ 444,129		$ 465,765
Allowance for loans and leases to total loans and leases ratio	1.55%		1.55%		1.40%
Balance of loans specifically evaluated for impairment	$ 5,343		$ 5,343		$ 5,273
Allowance for loans specifically evaluated for impairment	$ 1,884		$ 1,884		$ 1,318
Specific allowance to specific loans ratio	35.26%		35.26%		25.00%
Balance of loans collectively evaluated	$ 438,786		$ 438,786		$ 460,492
Allowance for loans collectively evaluated	5,012		$ 5,012		$ 5,211
Collective allowance to collective loans ratio			1.14%		1.13%
Leases
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of year			$ 0	9	$ 9
Provision (credit)					(5)
Charge-offs					(4)
Recoveries					0
Net charge-offs					(4)
Balance at period end					0
Total loans and leases					0
Consumer
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of year			3,456	3,592	3,592
Provision (credit)			81		619
Charge-offs			(674)		(998)
Recoveries			111		243
Net charge-offs			(563)		(755)
Balance at period end	2,974		2,974		3,456
Total loans and leases	$ 450,113		$ 450,113		$ 450,875
Allowance for loans and leases to total loans and leases ratio	0.66%		0.66%		0.77%
Balance of loans collectively evaluated	$ 450,113		$ 450,113		$ 450,875
Allowance for loans collectively evaluated	2,974		$ 2,974		$ 3,456
Collective allowance to collective loans ratio			0.66%		0.77%
Commercial Real Estate Portfolio Segment | Commercial Acquisition, Development and Construction
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of year			$ 4,691	4,267	$ 4,267
Provision (credit)			456		583
Charge-offs			(48)		(739)
Recoveries			22		580
Net charge-offs			(26)		(159)
Balance at period end	5,121		5,121		4,691
Total loans and leases	$ 302,522		$ 302,522		$ 255,980
Allowance for loans and leases to total loans and leases ratio	1.69%		1.69%		1.83%
Balance of loans specifically evaluated for impairment	$ 137		$ 137		$ 194
Allowance for loans specifically evaluated for impairment	$ 0		$ 0		$ 58
Specific allowance to specific loans ratio	0.00%		0.00%		29.90%
Balance of loans collectively evaluated	$ 302,385		$ 302,385		$ 255,786
Allowance for loans collectively evaluated	5,121		$ 5,121		$ 4,633
Collective allowance to collective loans ratio			1.69%		1.81%
Commercial Real Estate Portfolio Segment | Commercial Investor Real Estate
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of year			$ 10,440	9,784	$ 9,784
Provision (credit)			1,435		727
Charge-offs			(197)		(91)
Recoveries			124		20
Net charge-offs			(73)		(71)
Balance at period end	11,802		11,802		10,440
Total loans and leases	$ 847,946		$ 847,946		$ 719,084
Allowance for loans and leases to total loans and leases ratio	1.39%		1.39%		1.45%
Balance of loans specifically evaluated for impairment	$ 9,189		$ 9,189		$ 10,441
Allowance for loans specifically evaluated for impairment	$ 1,256		$ 1,256		$ 1,489
Specific allowance to specific loans ratio	13.67%		13.67%		14.26%
Balance of loans collectively evaluated	$ 838,757		$ 838,757		$ 708,643
Allowance for loans collectively evaluated	10,546		$ 10,546		$ 8,951
Collective allowance to collective loans ratio			1.26%		1.26%
Commercial Real Estate Portfolio Segment | Commercial Owner Occupied Real Estate
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of year			$ 7,984	7,143	$ 7,143
Provision (credit)			253		1,881
Charge-offs			0		(1,043)
Recoveries			5		3
Net charge-offs			5		(1,040)
Balance at period end	8,242		8,242		7,984
Total loans and leases	$ 736,744		$ 736,744		$ 678,027
Allowance for loans and leases to total loans and leases ratio	1.12%		1.12%		1.18%
Balance of loans specifically evaluated for impairment	$ 6,336		$ 6,336		$ 6,580
Allowance for loans specifically evaluated for impairment	$ 512		$ 512		$ 510
Specific allowance to specific loans ratio	8.08%		8.08%		7.75%
Balance of loans collectively evaluated	$ 730,408		$ 730,408		$ 671,447
Allowance for loans collectively evaluated	7,730		$ 7,730		$ 7,474
Collective allowance to collective loans ratio			1.06%		1.11%
Residential Real Estate Portfolio Segment | Residential Mortgage
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of year			$ 6,901	6,232	$ 6,232
Provision (credit)			2,132		1,138
Charge-offs			(1,378)		(614)
Recoveries			350		145
Net charge-offs			(1,028)		(469)
Balance at period end	8,005		8,005		6,901
Total loans and leases	$ 854,055		$ 854,055		$ 796,358
Allowance for loans and leases to total loans and leases ratio	0.94%		0.94%		0.87%
Balance of loans specifically evaluated for impairment	$ 3,292		$ 3,292		$ 6,439
Allowance for loans specifically evaluated for impairment	0		0		0
Balance of loans collectively evaluated	850,763		850,763		789,919
Allowance for loans collectively evaluated	8,005		$ 8,005		$ 6,901
Collective allowance to collective loans ratio			0.94%		0.87%
Residential Real Estate Portfolio Segment | Residential Construction
Financing Receivable Allowance For Credit Losses [Line Items]
Balance at beginning of year			$ 894	$ 923	$ 923
Provision (credit)			(18)		(80)
Charge-offs			0		0
Recoveries			26		51
Net charge-offs			26		51
Balance at period end	902		902		894
Total loans and leases	$ 144,998		$ 144,998		$ 129,281
Allowance for loans and leases to total loans and leases ratio	0.62%		0.62%		0.69%
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	144,998		144,998		129,281
Allowance for loans collectively evaluated	$ 902		$ 902		$ 894
Collective allowance to collective loans ratio			0.62%		0.69%