LOAN PORTFOLIO - Selected Information on TDRs Includes Recorded Investment by Loan Class and Modification Type (Parenthetical) (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable Modifications [Line Items]
Loans Receivable Held For Sale Net	$ 43,186	$ 32,980
Commercial Portfolio Segment [Member] | Commercial And Industrial Sector [Member]
Financing Receivable Modifications [Line Items]
Loans Receivable Held For Sale Net	1,725	0
Commercial Portfolio Segment [Member] | Mortgage Receivable [Member]
Financing Receivable Modifications [Line Items]
Loans Receivable Held For Sale Net	11,371	0
Nonperforming Financial Instruments [Member]
Financing Receivable Modifications [Line Items]
Loans Receivable Held For Sale Net	16,100	$ 8,300
Nonperforming Financial Instruments [Member] | Commercial Portfolio Segment [Member] | Commercial And Industrial Sector [Member]
Financing Receivable Modifications [Line Items]
Loans Receivable Held For Sale Net	1,700
Entity Loan Modification Program [Member] | Nonperforming Financial Instruments [Member] | Commercial Portfolio Segment [Member] | Commercial And Industrial Sector [Member]
Financing Receivable Modifications [Line Items]
Loans Receivable Held For Sale Net	900
Entity Loan Modification Program [Member] | Nonperforming Financial Instruments [Member] | Commercial Portfolio Segment [Member] | Mortgage Receivable [Member]
Financing Receivable Modifications [Line Items]
Loans Receivable Held For Sale Net	$ 11,100