CREDIT QUALITY ASSESSMENT (Summary Information on Allowance for Loan and Lease Loss Activity) (Detail) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Credit Quality Assessment [Abstract]
Balance at beginning of year				$ 44,067				$ 40,895	$ 44,067	$ 40,895	$ 37,802
Provision for loan losses	$ 527	$ 934	$ 1,322	$ 194	$ 572	$ 781	$ 2,957	$ 1,236	2,977	5,546	5,371
Loan and lease charge-offs									(2,566)	(3,134)	(3,795)
Loan and lease recoveries									779	760	1,517
Net charge-offs									(1,787)	(2,374)	(2,278)
Balance at period end	$ 45,257				$ 44,067				$ 45,257	$ 44,067	$ 40,895