Fair Value of Financial Instruments - Schedule of Carrying Amount and Estimated Fair Value of Financial Instruments (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022
Assets:
HTM investment securities	$ 1,485,506	$ 1,097,096
AFS investment securities	1,140,071	2,601,013
Derivative assets	44,939	78,129
Accrued interest receivable	68,516	73,784
Liabilities:
Derivative liabilities	13,603	12,598
Recurring
Assets:
AFS investment securities	1,140,071	2,601,013
Equity securities	759	13,526
Derivative assets	5,644	8,948
Liabilities:
Derivative liabilities	10,715	12,531
Level 1
Assets:
Cash and cash equivalents	936,473	1,101,249
HTM investment securities	0	0
AFS investment securities	0	0
Equity securities	759	925
Loans held for sale		0
Loans held for investment, net	0	0
Derivative assets	1	1
Accrued interest receivable	0	0
Liabilities:
Deposit accounts	0	0
FHLB advances	0	0
Subordinated debentures	0	0
Derivative liabilities	10	1
Accrued interest payable	0	0
Level 1 | Recurring
Assets:
AFS investment securities	0	0
Equity securities	759	925
Derivative assets	1	1
Liabilities:
Derivative liabilities	10	1
Level 1 | Interest-bearing time deposits with financial institutions
Assets:
Cash and cash equivalents	995	1,734
Level 2
Assets:
Cash and cash equivalents	0	0
HTM investment securities	1,485,506	1,097,096
AFS investment securities	1,140,071	2,601,013
Equity securities	0	0
Loans held for sale		2,755
Loans held for investment, net	0	0
Derivative assets	5,643	7,053
Accrued interest receivable	68,516	73,784
Liabilities:
Deposit accounts	15,003,769	17,334,219
FHLB advances	592,480	982,695
Subordinated debentures	320,687	327,609
Derivative liabilities	10,705	12,530
Accrued interest payable	18,671	14,661
Level 2 | Recurring
Assets:
AFS investment securities	1,140,071	2,601,013
Equity securities	0	0
Derivative assets	5,643	7,053
Liabilities:
Derivative liabilities	10,705	12,530
Level 2 | Interest-bearing time deposits with financial institutions
Assets:
Cash and cash equivalents	0	0
Level 3
Assets:
Cash and cash equivalents	0	0
HTM investment securities	0	0
AFS investment securities	0	0
Equity securities	0	0
Loans held for sale		0
Loans held for investment, net	12,562,323	13,846,403
Derivative assets	0	1,894
Accrued interest receivable	0	0
Liabilities:
Deposit accounts	0	0
FHLB advances	0	0
Subordinated debentures	0	0
Derivative liabilities	0	0
Accrued interest payable	0	0
Level 3 | Recurring
Assets:
AFS investment securities	0	0
Equity securities	0	0
Derivative assets	0	1,894
Liabilities:
Derivative liabilities	0	0
Level 3 | Interest-bearing time deposits with financial institutions
Assets:
Cash and cash equivalents	0	0
Carrying Amount
Assets:
Cash and cash equivalents	936,473	1,101,249
HTM investment securities	1,729,541	1,388,103
AFS investment securities	1,140,071	2,601,013
Equity securities	759	13,526
Loans held for sale		2,643
Loans held for investment, net	13,289,020	14,676,298
Derivative assets	5,644	8,948
Accrued interest receivable	68,516	73,784
Liabilities:
Deposit accounts	14,995,626	17,352,401
FHLB advances	600,000	1,000,000
Subordinated debentures	331,842	331,204
Derivative liabilities	10,715	12,531
Accrued interest payable	18,671	14,661
Carrying Amount | Interest-bearing time deposits with financial institutions
Assets:
Cash and cash equivalents	995	1,734
Estimated Fair Value
Assets:
Cash and cash equivalents	936,473	1,101,249
HTM investment securities	1,485,506	1,097,096
AFS investment securities	1,140,071	2,601,013
Equity securities	759	13,526
Loans held for sale		2,755
Loans held for investment, net	12,562,323	13,846,403
Derivative assets	5,644	8,948
Accrued interest receivable	68,516	73,784
Liabilities:
Deposit accounts	15,003,769	17,334,219
FHLB advances	592,480	982,695
Subordinated debentures	320,687	327,609
Derivative liabilities	10,715	12,531
Accrued interest payable	18,671	14,661
Estimated Fair Value | Interest-bearing time deposits with financial institutions
Assets:
Cash and cash equivalents	$ 995	$ 1,734