Loans Receivable - Summary of Various Categories of Loans Receivable (Details) - USD ($) $ in Thousands	Jun. 30, 2026	Mar. 31, 2026	Dec. 31, 2025	Jun. 30, 2025	Mar. 31, 2025	Dec. 31, 2024
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 17,127,208		$ 15,686,209
Allowance for credit losses	(328,369)	$ (297,634)	(297,583)	$ (281,869)	$ (279,944)	$ (275,880)
Loans receivable, net	16,798,839		15,388,626
Commercial real estate loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	9,031,176		8,349,517
Commercial real estate loans \| Non-farm/non-residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	5,921,829		5,290,112
Commercial real estate loans \| Construction/land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	2,780,116		2,726,993
Allowance for credit losses	(51,506)	(49,377)	(48,023)	(46,741)	(48,176)	(52,271)
Commercial real estate loans \| Agricultural
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	329,231		332,412
Residential real estate loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses	(86,150)	(71,983)	(72,692)	(57,972)	(53,408)	(50,835)
Residential real estate loans \| Residential 1-4 family
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	2,545,462		2,134,334
Residential real estate loans \| Multifamily residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	1,269,728		1,140,911
Total real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	12,846,366		11,624,762
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	1,278,008		1,253,746
Commercial and industrial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	2,285,054		2,222,401
Allowance for credit losses	(59,618)	$ (57,171)	(65,932)	$ (60,581)	$ (60,122)	$ (49,621)
Agricultural
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	356,611		359,879
Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans receivable	$ 361,169		$ 225,421