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, 2017	Mar. 31, 2016	Dec. 31, 2016
Segment Reporting Information [Line Items]
Interest income	$ 45,958	$ 41,653
Interest expense	5,705	5,531
Provision (credit)	194	1,236	$ 5,546
Non-interest income	12,632	13,363
Non-interest Expense	29,981	32,317
Income before income taxes	22,710	15,932
Income tax expense	7,598	5,119
Net income	15,112	10,813
Assets	5,201,164	4,716,608	$ 5,091,383
Intersegment Elimination
Segment Reporting Information [Line Items]
Interest income	(2)	(2)
Interest expense	(2)	(2)
Provision (credit)	0	0
Non-interest income	(209)	(178)
Non-interest Expense	(209)	(178)
Income before income taxes	0	0
Income tax expense	0	0
Net income	0	0
Assets	(24,039)	(21,029)
Community Banking
Segment Reporting Information [Line Items]
Interest income	45,957	41,653
Interest expense	5,707	5,533
Provision (credit)	194	1,236
Non-interest income	9,086	10,219
Non-interest Expense	27,799	30,380
Income before income taxes	21,343	14,723
Income tax expense	7,060	4,644
Net income	14,283	10,079
Assets	5,202,560	4,719,759
Insurance
Segment Reporting Information [Line Items]
Interest income	1	1
Interest expense	0	0
Provision (credit)	0	0
Non-interest income	1,752	1,453
Non-interest Expense	1,355	1,171
Income before income taxes	398	283
Income tax expense	161	114
Net income	237	169
Assets	8,066	5,790
Investment Management
Segment Reporting Information [Line Items]
Interest income	2	1
Interest expense	0	0
Provision (credit)	0	0
Non-interest income	2,003	1,869
Non-interest Expense	1,036	944
Income before income taxes	969	926
Income tax expense	377	361
Net income	592	565
Assets	$ 14,577	$ 12,088