CREDIT QUALITY ASSESSMENT (Summary of Impaired Loans) (Detail) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended	12 Months Ended
	Jun. 30, 2018	Jun. 30, 2018	Dec. 31, 2017
Credit Quality Assessment [Abstract]
Impaired loans with a specific allowance	$ 11,829	$ 11,829	$ 11,693
Impaired loans without a specific allowance	7,068	7,068	9,116
Total impaired loans	18,897	18,897	20,809
Allowance for loan and lease losses related to impaired loans	4,503	4,503	4,014
Allowance for loan and lease losses related to loans collectively evaluated	43,990	43,990	41,243
Total allowance for loan and lease losses	48,493	48,493	45,257
Average impaired loans for the period	$ 20,166	20,166	23,179
Contractual interest income due on impaired loans during the period		1,298	2,314
Interest income on impaired loans recognized on a cash basis		302	754
Interest income on impaired loans recognized on an accrual basis		$ 64	$ 169