LHFI and ACL, LHFI - Loan Portfolio Held for Investment (Details) - USD ($) $ in Thousands	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Loan Portfolio [Abstract]
Total LHFI	$ 12,950,524	$ 12,204,039
Less ACL, LHFI	139,367	120,214	$ 99,457	$ 117,306
Net LHFI	12,811,157	12,083,825
Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member]
Loan Portfolio [Abstract]
Total LHFI	642,886	690,616
Other Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member]
Loan Portfolio [Abstract]
Total LHFI	622,397	590,790
Secured by 1-4 Family Residential Properties [Member] | Other Loans Secured by Real Estate [Member]
Loan Portfolio [Abstract]
Total LHFI	2,282,318	2,185,057
Other Real Estate Secured [Member] | Loans Secured by Real Estate [Member]
Loan Portfolio [Abstract]
Total LHFI	1,312,551	742,538
Other Construction [Member] | Other Loans Secured by Real Estate [Member]
Loan Portfolio [Abstract]
Total LHFI	867,793	1,028,926
Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member]
Loan Portfolio [Abstract]
Total LHFI	3,489,434	3,278,830
Less ACL, LHFI	24,043	19,488	37,912
Commercial and Industrial Loans [Member]
Loan Portfolio [Abstract]
Total LHFI	1,922,910	1,821,259
Less ACL, LHFI	26,638	23,140	18,939
Consumer Loans [Member]
Loan Portfolio [Abstract]
Total LHFI	165,734	170,230
Less ACL, LHFI	5,794	5,792	4,774
State and Other Political Subdivision Loans [Member]
Loan Portfolio [Abstract]
Total LHFI	1,088,466	1,223,863
Less ACL, LHFI	646	885	$ 2,708
Other Commercial Loans and Leases [Member]
Loan Portfolio [Abstract]
Total LHFI	556,035	471,930
Less ACL, LHFI	$ 7,072	$ 4,647