FAIR VALUE - Financial Assets and Liabilities Accounted for or Disclosed at Fair Value (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Residential mortgage loans held for sale (at fair value)	$ 39,409	$ 78,294
Investments available-for-sale:	1,465,896	1,348,021
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)	38,200	75,500
Fair Value, Measurements, Recurring
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments available-for-sale:	1,465,896	1,348,021
Total assets	1,511,185	1,435,498
Total liabilities	(5,880)	(9,183)
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)	39,409	78,294
Fair Value, Measurements, Recurring | U.S. treasuries and government agencies
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments available-for-sale:	68,539	43,297
Fair Value, Measurements, Recurring | State and municipal
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments available-for-sale:	326,402	390,367
Fair Value, Measurements, Recurring | Mortgage-backed and asset-backed
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments available-for-sale:	1,070,955	904,432
Fair Value, Measurements, Recurring | Corporate debt
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments available-for-sale:	0	9,925
Fair Value, Measurements, Recurring | Total swaps
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swap agreements	5,880	9,183
Interest rate swap agreements	(5,880)	(9,183)
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments available-for-sale:	0	0
Total assets	0	0
Total liabilities	0	0
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:	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:	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:	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:	0	0
Fair Value, Measurements, Recurring | Quoted Prices in Active Markets for Identical Assets (Level 1) | Total swaps
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swap agreements	0	0
Interest rate swap agreements	0	0
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments available-for-sale:	1,465,896	1,338,096
Total assets	1,511,185	1,425,573
Total liabilities	(5,880)	(9,183)
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)	39,409	78,294
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:	68,539	43,297
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:	326,402	390,367
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:	1,070,955	904,432
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:	0	0
Fair Value, Measurements, Recurring | Significant Other Observable Inputs (Level 2) | Total swaps
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swap agreements	5,880	9,183
Interest rate swap agreements	(5,880)	(9,183)
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3)
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Investments available-for-sale:	0	9,925
Total assets	0	9,925
Total liabilities	0	0
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:	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:	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:	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:	0	9,925
Fair Value, Measurements, Recurring | Significant Unobservable Inputs (Level 3) | Total swaps
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Interest rate swap agreements	0	0
Interest rate swap agreements	$ 0	$ 0