FAIR VALUE - Carrying Amounts and Fair Values of Company's Financial Instruments (Detail) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Financial assets:
Residential mortgage loans held for sale	$ 39,409	$ 78,294
Investments available-for-sale:	1,465,896	1,348,021
Loans, net of allowance	9,857,946	10,235,142
Accrued interest receivable	34,349	46,431
Financial liabilities:
Time deposits	1,290,862
Other deposits	10,624,731	10,033,069
Securities sold under retail repurchase agreements and federal funds purchased	141,086	543,157
Advances from FHLB	0	379,075
Subordinated debt	172,712	227,088
Carrying Amount
Financial assets:
Cash and cash equivalents	420,020	297,003
Residential mortgage loans held for sale	39,409	78,294
Investments available-for-sale:	1,465,896	1,348,021
Equity securities	41,166	65,760
Loans, net of allowance	9,857,946	10,235,142
Interest rate swap agreements	5,880	9,183
Accrued interest receivable	34,349	46,431
Bank owned life insurance	147,528	126,887
Financial liabilities:
Time deposits	1,290,862	1,657,662
Other deposits	9,333,869	8,375,407
Securities sold under retail repurchase agreements and federal funds purchased	141,086	543,157
Advances from FHLB	0	379,075
Subordinated debt	172,712	227,088
Interest rate swap agreements	5,880	9,183
Accrued interest payable	1,516	3,254
Estimated Fair Value
Financial assets:
Cash and cash equivalents	420,020	297,003
Residential mortgage loans held for sale	39,409	78,294
Investments available-for-sale:	1,465,896	1,348,021
Equity securities	41,166	65,760
Loans, net of allowance	9,964,924	10,336,355
Interest rate swap agreements	5,880	9,183
Accrued interest receivable	34,349	46,431
Bank owned life insurance	147,528	126,887
Financial liabilities:
Time deposits	1,292,598	1,674,112
Other deposits	9,333,869	8,375,407
Securities sold under retail repurchase agreements and federal funds purchased	141,086	543,157
Advances from FHLB	0	390,593
Subordinated debt	175,780	227,512
Interest rate swap agreements	5,880	9,183
Accrued interest payable	1,516	3,254
Quoted Prices in Active Markets for Identical Assets (Level 1) | Estimated Fair Value
Financial assets:
Cash and cash equivalents	420,020	297,003
Residential mortgage loans held for sale	0	0
Investments available-for-sale:	0	0
Equity securities	41,166	65,760
Loans, net of allowance	0	0
Interest rate swap agreements	0	0
Accrued interest receivable	34,349	46,431
Bank owned life insurance	0	0
Financial liabilities:
Time deposits	0	0
Other deposits	9,333,869	8,375,407
Securities sold under retail repurchase agreements and federal funds purchased	0	0
Advances from FHLB	0	0
Subordinated debt	0	0
Interest rate swap agreements	0	0
Accrued interest payable	1,516	3,254
Significant Other Observable Inputs (Level 2) | Estimated Fair Value
Financial assets:
Cash and cash equivalents	0	0
Residential mortgage loans held for sale	39,409	78,294
Investments available-for-sale:	1,465,896	1,338,096
Equity securities	0	0
Loans, net of allowance	0	0
Interest rate swap agreements	5,880	9,183
Accrued interest receivable	0	0
Bank owned life insurance	147,528	126,887
Financial liabilities:
Time deposits	1,292,598	1,674,112
Other deposits	0	0
Securities sold under retail repurchase agreements and federal funds purchased	141,086	543,157
Advances from FHLB	0	390,593
Subordinated debt	0	0
Interest rate swap agreements	5,880	9,183
Accrued interest payable	0	0
Significant Unobservable Inputs (Level 3) | Estimated Fair Value
Financial assets:
Cash and cash equivalents	0	0
Residential mortgage loans held for sale	0	0
Investments available-for-sale:	0	9,925
Equity securities	0	0
Loans, net of allowance	9,964,924	10,336,355
Interest rate swap agreements	0	0
Accrued interest receivable	0	0
Bank owned life insurance	0	0
Financial liabilities:
Time deposits	0	0
Other deposits	0	0
Securities sold under retail repurchase agreements and federal funds purchased	0	0
Advances from FHLB	0	0
Subordinated debt	175,780	227,512
Interest rate swap agreements	0	0
Accrued interest payable	$ 0	$ 0