CREDIT QUALITY ASSESSMENT (Summary Information on Allowance for Loan and Lease Loss Activity) (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Credit Quality Assessment [Abstract]
Balance at beginning of year			$ 45,257	$ 44,067	$ 44,067
Provision for loan losses	$ 1,890	$ 934	5,620	2,450	2,977
Loan and lease charge-offs			(1,003)	(2,044)	(2,566)
Loan and lease recoveries			535	451	779
Net charge-offs			(468)	(1,593)	(1,787)
Balance at period end	$ 50,409	$ 44,924	$ 50,409	$ 44,924	$ 45,257