Fair Value Information - Estimated Fair Value of Financial Instruments (Detail) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Assets
Total cash and cash equivalents	$ 203,461	$ 1,732,548
Investment securities available-for-sale	3,255,211	3,183,923
Investment securities held-to-maturity	2,554,301	1,925,970
Total loans, net of allowance for credit losses	8,994,275	7,822,694
Derivative Asset	82	14,163
Deposits:
Interest-bearing	4,671,881	4,872,386
Financial liabilities, Net Amounts Presented in the Consolidated Balance Sheets	565,513	656,551
Carrying Value [Member]
Assets
Total cash and cash equivalents	203,461	1,732,548
Interest-earning balances due from depository institutions	9,553	25,999
Investment securities available-for-sale	3,255,211	3,183,923
Investment securities held-to-maturity	2,554,301	1,925,970
Total loans, net of allowance for credit losses	8,994,275	7,822,694
Derivative Asset	82	14,163
Deposits:
Interest-bearing	4,671,881	4,872,386
Borrowings	1,560,431	644,669
Junior subordinated debentures	0	0
Financial liabilities, Net Amounts Presented in the Consolidated Balance Sheets	82	14,163
Estimated Fair Value [Member]
Assets
Total cash and cash equivalents	203,461	1,732,548
Interest-earning balances due from depository institutions	9,553	25,999
Investment securities available-for-sale	3,255,211	3,183,923
Investment securities held-to-maturity	2,155,587	1,921,693
Total loans, net of allowance for credit losses	8,074,952	7,696,210
Derivative Asset	82	14,163
Deposits:
Interest-bearing	4,664,657	4,871,531
Borrowings	1,444,659	586,645
Junior subordinated debentures	0	0
Financial liabilities, Net Amounts Presented in the Consolidated Balance Sheets	82	14,163
Estimated Fair Value [Member] | Level 1 [Member]
Assets
Total cash and cash equivalents	203,461	1,732,548
Interest-earning balances due from depository institutions	0	0
Investment securities available-for-sale	0	0
Investment securities held-to-maturity	0	0
Total loans, net of allowance for credit losses	0	0
Derivative Asset	0	0
Deposits:
Interest-bearing	0	0
Borrowings	0	0
Junior subordinated debentures	0	0
Financial liabilities, Net Amounts Presented in the Consolidated Balance Sheets	0	0
Estimated Fair Value [Member] | Level 2 [Member]
Assets
Total cash and cash equivalents	0	0
Interest-earning balances due from depository institutions	9,553	25,999
Investment securities available-for-sale	3,255,211	3,183,923
Investment securities held-to-maturity	2,155,587	1,921,693
Total loans, net of allowance for credit losses	0	0
Derivative Asset	82	14,163
Deposits:
Interest-bearing	4,664,657	4,871,531
Borrowings	1,444,659	586,645
Junior subordinated debentures	0	0
Financial liabilities, Net Amounts Presented in the Consolidated Balance Sheets	82	14,163
Estimated Fair Value [Member] | Level 3 [Member]
Assets
Total cash and cash equivalents	0	0
Interest-earning balances due from depository institutions	0	0
Investment securities available-for-sale	0	0
Investment securities held-to-maturity	0	0
Total loans, net of allowance for credit losses	8,074,952	7,696,210
Derivative Asset	0	0
Deposits:
Interest-bearing	0	0
Borrowings	0	0
Junior subordinated debentures	0	0
Financial liabilities, Net Amounts Presented in the Consolidated Balance Sheets	$ 0	$ 0