Allowance for Credit Losses, Credit Quality and Other - Summary of Aging Analysis for Loans Receivable (Details) - USD ($) $ in Thousands	Sep. 30, 2025	Dec. 31, 2024
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	$ 15,285,972	$ 14,764,500
Accruing Loans Past Due 90 Days or More	4,125	5,034
Loans Past Due 30-59 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	12,385	15,145
Loans Past Due 60-89 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	10,057	46,050
Loans Past Due 90 Days or More
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	85,212	98,887
Total Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	107,654	160,082
Current Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	15,178,318	14,604,418
Commercial real estate loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	8,534,990	8,499,987
Commercial real estate loans \| Non-farm/non-residential
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	5,494,492	5,426,780
Accruing Loans Past Due 90 Days or More	1,136	304
Commercial real estate loans \| Non-farm/non-residential \| Loans Past Due 30-59 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	5,581	4,352
Commercial real estate loans \| Non-farm/non-residential \| Loans Past Due 60-89 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	1,101	38,944
Commercial real estate loans \| Non-farm/non-residential \| Loans Past Due 90 Days or More
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	23,437	36,172
Commercial real estate loans \| Non-farm/non-residential \| Total Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	30,119	79,468
Commercial real estate loans \| Non-farm/non-residential \| Current Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	5,464,373	5,347,312
Commercial real estate loans \| Construction/land development
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	2,709,197	2,736,214
Accruing Loans Past Due 90 Days or More	0	600
Commercial real estate loans \| Construction/land development \| Loans Past Due 30-59 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	2,467	369
Commercial real estate loans \| Construction/land development \| Loans Past Due 60-89 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	413	799
Commercial real estate loans \| Construction/land development \| Loans Past Due 90 Days or More
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	3,418	4,302
Commercial real estate loans \| Construction/land development \| Total Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	6,298	5,470
Commercial real estate loans \| Construction/land development \| Current Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	2,702,899	2,730,744
Commercial real estate loans \| Agricultural
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	331,301	336,993
Accruing Loans Past Due 90 Days or More	0	0
Commercial real estate loans \| Agricultural \| Loans Past Due 30-59 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	55	90
Commercial real estate loans \| Agricultural \| Loans Past Due 60-89 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	0	43
Commercial real estate loans \| Agricultural \| Loans Past Due 90 Days or More
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	497	559
Commercial real estate loans \| Agricultural \| Total Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	552	692
Commercial real estate loans \| Agricultural \| Current Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	330,749	336,301
Residential real estate loans \| Residential 1-4 family
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	2,142,375	1,956,489
Accruing Loans Past Due 90 Days or More	1,529	1,835
Residential real estate loans \| Residential 1-4 family \| Loans Past Due 30-59 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	999	1,897
Residential real estate loans \| Residential 1-4 family \| Loans Past Due 60-89 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	7,864	4,877
Residential real estate loans \| Residential 1-4 family \| Loans Past Due 90 Days or More
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	27,076	24,374
Residential real estate loans \| Residential 1-4 family \| Total Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	35,939	31,148
Residential real estate loans \| Residential 1-4 family \| Current Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	2,106,436	1,925,341
Residential real estate loans \| Multifamily residential
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	716,595	496,484
Accruing Loans Past Due 90 Days or More	0	0
Residential real estate loans \| Multifamily residential \| Loans Past Due 30-59 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	0	0
Residential real estate loans \| Multifamily residential \| Loans Past Due 60-89 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	0	0
Residential real estate loans \| Multifamily residential \| Loans Past Due 90 Days or More
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	12,907	13,083
Residential real estate loans \| Multifamily residential \| Total Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	12,907	13,083
Residential real estate loans \| Multifamily residential \| Current Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	703,688	483,401
Total real estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	11,393,960	10,952,960
Accruing Loans Past Due 90 Days or More	2,665	2,739
Total real estate \| Loans Past Due 30-59 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	9,102	6,708
Total real estate \| Loans Past Due 60-89 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	9,378	44,663
Total real estate \| Loans Past Due 90 Days or More
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	67,335	78,490
Total real estate \| Total Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	85,815	129,861
Total real estate \| Current Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	11,308,145	10,823,099
Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	1,233,523	1,234,361
Accruing Loans Past Due 90 Days or More	4	32
Consumer \| Loans Past Due 30-59 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	741	7,046
Consumer \| Loans Past Due 60-89 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	14	68
Consumer \| Loans Past Due 90 Days or More
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	10,802	6,210
Consumer \| Total Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	11,557	13,324
Consumer \| Current Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	1,221,966	1,221,037
Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	2,100,268	2,022,775
Accruing Loans Past Due 90 Days or More	1,456	2,263
Commercial and industrial \| Loans Past Due 30-59 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	1,459	309
Commercial and industrial \| Loans Past Due 60-89 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	594	1,028
Commercial and industrial \| Loans Past Due 90 Days or More
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	5,805	13,194
Commercial and industrial \| Total Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	7,858	14,531
Commercial and industrial \| Current Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	2,092,410	2,008,244
Agricultural & other
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	558,221	554,404
Accruing Loans Past Due 90 Days or More	0	0
Agricultural & other \| Loans Past Due 30-59 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	1,083	1,082
Agricultural & other \| Loans Past Due 60-89 Days
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	71	291
Agricultural & other \| Loans Past Due 90 Days or More
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	1,270	993
Agricultural & other \| Total Past Due
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	2,424	2,366
Agricultural & other \| Current Loans
Financing Receivable, Recorded Investment, Past Due [Line Items]
Loans	$ 555,797	$ 552,038