LHFI and ACL, LHFI - Loan Portfolio Held for Investment (Details) - USD ($) $ in Thousands	Jun. 30, 2026	Mar. 31, 2026	Dec. 31, 2025	Jun. 30, 2025	Mar. 31, 2025	Dec. 31, 2024
Loan Portfolio [Abstract]
Total LHFI	$ 13,913,023		$ 13,674,233
Less ACL, LHFI	148,189	$ 160,431	157,071	$ 168,237	$ 167,010	$ 160,270
Net LHFI	13,764,834		13,517,162
Construction, Land Development and Other Land [Member] \| Loans Secured by Real Estate [Member]
Loan Portfolio [Abstract]
Total LHFI	555,731		549,353
Other Secured by 1-4 Family Residential Properties [Member] \| Loans Secured by Real Estate [Member]
Loan Portfolio [Abstract]
Total LHFI	721,362		704,514
Secured by 1-4 Family Residential Properties [Member] \| Other Loans Secured by Real Estate [Member]
Loan Portfolio [Abstract]
Total LHFI	2,357,203		2,351,675
Other Real Estate Secured [Member] \| Loans Secured by Real Estate [Member]
Loan Portfolio [Abstract]
Total LHFI	1,990,550		2,124,272
Other Construction [Member] \| Other Loans Secured by Real Estate [Member]
Loan Portfolio [Abstract]
Total LHFI	661,069		595,238
Secured by Nonfarm, Nonresidential Properties [Member] \| Loans Secured by Real Estate [Member]
Loan Portfolio [Abstract]
Total LHFI	3,198,800		3,304,523
Less ACL, LHFI	30,449	31,093	35,183	35,017	39,973	37,896
Commercial and Industrial Loans [Member]
Loan Portfolio [Abstract]
Total LHFI	2,294,721		1,999,464
Less ACL, LHFI	31,100	24,800	20,569	28,465	25,396	27,020
Consumer Loans [Member]
Loan Portfolio [Abstract]
Total LHFI	160,648		163,754
Less ACL, LHFI	6,350	6,137	5,843	5,111	5,238	5,141
State and Other Political Subdivision Loans [Member]
Loan Portfolio [Abstract]
Total LHFI	1,046,511		1,061,584
Less ACL, LHFI	711	773	865	1,547	1,605	1,250
Other Commercial Loans and Leases [Member]
Loan Portfolio [Abstract]
Total LHFI	926,428		819,856
Less ACL, LHFI	$ 9,841	$ 9,063	$ 8,009	$ 7,451	$ 6,530	$ 6,247