FAIR VALUE (Financial Assets and Liabilities at Dates Indicated that Were Accounted for or Disclosed at Fair Value) (Detail) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Residential mortgage loans held for sale (at fair value)	$ 9,848	$ 13,222
Investments available-for-sale (at fair value)	729,507	733,554
Fair Value, Measurements, Recurring | Residential Mortgage Loans Held For Sale
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Residential mortgage loans held for sale (at fair value)	9,848	13,222
Fair Value, Measurements, Recurring | U.S. Government Agencies
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	106,568	121,790
Fair Value, Measurements, Recurring | State and municipal
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	312,253	287,684
Fair Value, Measurements, Recurring | Mortgage-Backed
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	300,040	312,711
Fair Value, Measurements, Recurring | Corporate Debt
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	9,432	9,134
Fair Value, Measurements, Recurring | Trust Preferred
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	1,002	1,012
Fair Value, Measurements, Recurring | Marketable Equity Securities
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	212	1,223
Fair Value, Measurements, Recurring | Interest Rate Swap Agreements
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Other assets	707	1,010
Other liabilities	(707)	(1,010)
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Residential Mortgage Loans Held For Sale
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Residential mortgage loans held for sale (at fair value)	0	0
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | U.S. Government Agencies
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	0	0
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | State and municipal
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	0	0
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Mortgage-Backed
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	0	0
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Corporate Debt
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	0	0
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Trust Preferred
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	0	0
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Marketable Equity Securities
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	0	0
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Interest Rate Swap Agreements
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Other assets	0	0
Other liabilities	0	0
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Residential Mortgage Loans Held For Sale
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Residential mortgage loans held for sale (at fair value)	9,848	13,222
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | U.S. Government Agencies
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	106,568	121,790
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | State and municipal
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	312,253	287,684
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Mortgage-Backed
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	300,040	312,711
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Corporate Debt
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	0	0
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Trust Preferred
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	0	0
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Marketable Equity Securities
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	212	1,223
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Interest Rate Swap Agreements
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Other assets	707	1,010
Other liabilities	(707)	(1,010)
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3) | Residential Mortgage Loans Held For Sale
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Residential mortgage loans held for sale (at fair value)	0	0
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3) | U.S. Government Agencies
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	0	0
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3) | State and municipal
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	0	0
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3) | Mortgage-Backed
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	0	0
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3) | Corporate Debt
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	9,432	9,134
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3) | Trust Preferred
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	1,002	1,012
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3) | Marketable Equity Securities
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	0	0
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3) | Interest Rate Swap Agreements
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Other assets	0	0
Other liabilities	$ 0	$ 0