FAIR VALUE (Financial Assets and Liabilities at Dates Indicated that Were Accounted for or Disclosed at Fair Value) (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Residential mortgage loans held for sale (at fair value)	$ 28,486	$ 9,848
Investments available-for-sale (at fair value)	977,224	729,507
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)	28,486	9,848
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)	208,304	106,568
Fair Value, Measurements, Recurring | State and municipal
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	330,546	312,253
Fair Value, Measurements, Recurring | Mortgage-Backed
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	428,144	300,040
Fair Value, Measurements, Recurring | Corporate Debt
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	9,352	9,432
Fair Value, Measurements, Recurring | Trust Preferred
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	310	1,002
Fair Value, Measurements, Recurring | Marketable Equity Securities
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	568	212
Fair Value, Measurements, Recurring | Interest Rate Swap Agreements
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Other assets	574	707
Other liabilities	(574)	(707)
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)	28,486	9,848
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)	208,304	106,568
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)	330,546	312,253
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)	428,144	300,040
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)	568	212
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	574	707
Other liabilities	(574)	(707)
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)	9,352	9,432
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)	310	1,002
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