SEGMENT REPORTING (Operating Segments and Reconciliation of Information to Condensed Consolidated Financial Statements) (Detail) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Mar. 31, 2016	Mar. 31, 2015	Dec. 31, 2015
Segment Reporting Information [Line Items]
Interest income	$ 41,653	$ 38,072
Interest expense	5,531	4,699
Provision (credit)	1,236	597	$ 5,371
Non-interest income	13,363	13,159
Non-interest Expense	32,317	29,244
Income before income taxes	15,932	16,691
Income tax expense	5,119	5,466
Net income	10,813	11,225
Assets	4,716,608	4,401,380	$ 4,655,380
Intersegment Elimination
Segment Reporting Information [Line Items]
Interest income	(2)	(1)
Interest expense	(2)	(1)
Provision (credit)	0	0
Non-interest income	(178)	(181)
Non-interest Expense	(178)	(181)
Income before income taxes	0	0
Income tax expense	0	0
Net income	0	0
Assets	(21,029)	(21,391)
Community Banking
Segment Reporting Information [Line Items]
Interest income	41,653	38,071
Interest expense	5,533	4,700
Provision (credit)	1,236	597
Non-interest income	10,219	9,836
Non-interest Expense	30,380	27,017
Income before income taxes	14,723	15,593
Income tax expense	4,644	5,034
Net income	10,079	10,559
Assets	4,719,759	4,403,060
Insurance
Segment Reporting Information [Line Items]
Interest income	1	1
Interest expense	0	0
Provision (credit)	0	0
Non-interest income	1,453	1,694
Non-interest Expense	1,171	1,383
Income before income taxes	283	312
Income tax expense	114	126
Net income	169	186
Assets	5,790	5,948
Investment Management
Segment Reporting Information [Line Items]
Interest income	1	1
Interest expense	0	0
Provision (credit)	0	0
Non-interest income	1,869	1,810
Non-interest Expense	944	1,025
Income before income taxes	926	786
Income tax expense	361	306
Net income	565	480
Assets	$ 12,088	$ 13,763