FAIR VALUE (Financial Assets and Liabilities at Dates Indicated that Were Accounted for or Disclosed at Fair Value) (Detail) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Residential mortgage loans held for sale (at fair value)	$ 68,765	$ 53,701
Investments available-for-sale (at fair value)	1,355,799	1,073,333
U.S. treasuries and government agencies
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	168,072	258,495
State and municipal
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	297,580	233,649
Mortgage-Backed and asset-backed
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	877,955	570,759
Corporate Debt
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	12,192	9,552
Trust Preferred
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	0	310
Marketable Equity Securities
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	0	568
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)	68,765	53,701
Fair Value, Measurements, Recurring | U.S. treasuries and government agencies
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	168,072	258,495
Fair Value, Measurements, Recurring | State and municipal
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	297,580	233,649
Fair Value, Measurements, Recurring | Mortgage-Backed and asset-backed
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	877,955	570,759
Fair Value, Measurements, Recurring | Corporate Debt
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	12,192	9,552
Fair Value, Measurements, Recurring | Trust Preferred
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	0	310
Fair Value, Measurements, Recurring | Marketable Equity Securities
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	677	568
Fair Value, Measurements, Recurring | Interest Rate Swap Agreements
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Other assets	10,804	2,507
Other liabilities	(10,804)	(2,507)
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. treasuries and 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 and asset-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)	68,765	53,701
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | U.S. treasuries and government agencies
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	168,072	258,495
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)	297,580	233,649
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Mortgage-Backed and asset-backed
Fair Value Balance Sheet Grouping Financial Statement Captions [Line Items]
Investments available-for-sale (at fair value)	877,955	570,759
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)	677	568
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	10,804	2,507
Other liabilities	(10,804)	(2,507)
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. treasuries and 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 and asset-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)	12,192	9,552
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)	0	310
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