LOAN PORTFOLIO- Carrying Value of Purchased Credit Impaired Loans (Detail) - USD ($) $ in Thousands	Sep. 30, 2017		Jun. 30, 2017	Dec. 31, 2016		Sep. 30, 2016	Jun. 30, 2016	Dec. 31, 2015
Financing Receivable Impaired [Line Items]
Purchased Credit Impaired Loans	$ 157,794		$ 160,368	$ 165,818		$ 168,141	$ 169,690	$ 173,913
Allowance for loan losses Purchased Credit Impaired	(10,235)		$ (9,446)	(6,857)		(6,857)	$ (6,857)	$ (3,962)
Purchased Credit Impaired Loans, Net	147,559			158,961		$ 161,284
Residential Mortgage Loans [Member]
Financing Receivable Impaired [Line Items]
Purchased Credit Impaired Loans	153,609	[1]		162,676	[2]
Commercial Mortgage Loans [Member]
Financing Receivable Impaired [Line Items]
Purchased Credit Impaired Loans	$ 4,185	[1]		$ 3,142	[2]

[1] According to the Corporation's delinquency policy and consistent with the instructions for the preparation of the Consolidated Financial Statements for Bank Holding Companies (FR Y-9C) required by the Federal Reserve Board, residential mortgage, commercial mortgage, and construction loans are considered past due when the borrower is in arrears on two or more monthly payments. FHA/VA government-guaranteed loans, other residential mortgage loans, commercial mortgage loans, land loans, construction-residential loans and construction-commercial loans past due 30-59 days as of September 30, 2017 amounted to $9.4 million, $216.1 million, $33.8 million, $0.9 million, $6.4 million and $0.1 million, respectively.

[2] According to the Corporation's delinquency policy and consistent with the instructions for the preparation of the Consolidated Financial Statements for Bank Holding Companies (FR Y-9C) required by the Federal Reserve Board, residential mortgage, commercial mortgage, and construction loans are considered past due when the borrower is in arrears on two or more monthly payments. FHA/VA government-guaranteed loans, other residential mortgage loans, commercial mortgage loans, land loans and construction-residential loans past due 30-59 days as of December 31, 2016 amounted to $9.9 million, $142.8 million, $4.6 million, $0.7 million and $0.4 million, respectively.