FAIR VALUE - Carrying Amounts and Fair Values of Company's Financial Instruments (Detail) - USD ($) $ in Thousands	Mar. 31, 2022	Dec. 31, 2021
Financial assets:
Residential mortgage loans held for sale	$ 17,537	$ 39,409
Investments available-for-sale	1,259,945	1,465,896
Held-to-maturity debt securities:	275,834	0
Loans, net of allowance	10,033,740	9,857,946
Accrued interest receivable	33,528	34,349
Financial liabilities:
Other deposits	10,852,794	10,624,731
Securities sold under retail repurchase agreements and federal funds purchased	130,784	141,086
Subordinated debt	370,002	172,712
Carrying Amount
Financial assets:
Cash and cash equivalents	552,826	420,020
Residential mortgage loans held for sale	17,537	39,409
Investments available-for-sale	1,259,945	1,465,896
Held-to-maturity debt securities:	285,339
Equity securities	41,157	41,166
Loans, net of allowance	10,033,740	9,857,946
Interest rate swap agreements	8,239	5,880
Accrued interest receivable	33,528	34,349
Bank owned life insurance	148,323	147,528
Financial liabilities:
Time deposits	1,362,579	1,290,862
Other deposits	9,490,215	9,333,869
Securities sold under retail repurchase agreements and federal funds purchased	130,784	141,086
Subordinated debt	370,002	172,712
Interest rate swap agreements	8,239	5,880
Accrued interest payable	3,598	1,516
Estimated Fair Value
Financial assets:
Cash and cash equivalents	552,826	420,020
Residential mortgage loans held for sale	17,537	39,409
Investments available-for-sale	1,259,945	1,465,896
Held-to-maturity debt securities:	275,834
Equity securities	41,157	41,166
Loans, net of allowance	10,110,642	9,964,924
Interest rate swap agreements	8,239	5,880
Accrued interest receivable	33,528	34,349
Bank owned life insurance	148,323	147,528
Financial liabilities:
Time deposits	1,353,092	1,292,598
Other deposits	9,490,215	9,333,869
Securities sold under retail repurchase agreements and federal funds purchased	130,784	141,086
Subordinated debt	313,553	175,780
Interest rate swap agreements	8,239	5,880
Accrued interest payable	3,598	1,516
Quoted Prices in Active Markets for Identical Assets (Level 1) | Estimated Fair Value
Financial assets:
Cash and cash equivalents	552,826	420,020
Residential mortgage loans held for sale	0	0
Investments available-for-sale	0	0
Held-to-maturity debt securities:	0
Equity securities	41,157	41,166
Loans, net of allowance	0	0
Interest rate swap agreements	0	0
Accrued interest receivable	33,528	34,349
Bank owned life insurance	0	0
Financial liabilities:
Time deposits	0	0
Other deposits	9,490,215	9,333,869
Securities sold under retail repurchase agreements and federal funds purchased	0	0
Subordinated debt	0	0
Interest rate swap agreements	0	0
Accrued interest payable	3,598	1,516
Significant Other Observable Inputs (Level 2) | Estimated Fair Value
Financial assets:
Cash and cash equivalents	0	0
Residential mortgage loans held for sale	17,537	39,409
Investments available-for-sale	1,259,945	1,465,896
Held-to-maturity debt securities:	275,834
Equity securities	0	0
Loans, net of allowance	0	0
Interest rate swap agreements	8,239	5,880
Accrued interest receivable	0	0
Bank owned life insurance	148,323	147,528
Financial liabilities:
Time deposits	1,353,092	1,292,598
Other deposits	0	0
Securities sold under retail repurchase agreements and federal funds purchased	130,784	141,086
Subordinated debt	0	0
Interest rate swap agreements	8,239	5,880
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	0
Held-to-maturity debt securities:	0
Equity securities	0	0
Loans, net of allowance	10,110,642	9,964,924
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
Subordinated debt	313,553	175,780
Interest rate swap agreements	0	0
Accrued interest payable	$ 0	$ 0