Loans and Allowance for Credit Losses - Loan Portfolio by Categories (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 15,110,344	$ 12,012,503
Consumer
Loans and Leases Receivable Disclosure [Line Items]
Loans	394,376	355,370
Consumer | Credit cards
Loans and Leases Receivable Disclosure [Line Items]
Loans	189,684	187,052
Consumer | Other consumer
Loans and Leases Receivable Disclosure [Line Items]
Loans	204,692	168,318
Real Estate
Loans and Leases Receivable Disclosure [Line Items]
Loans	11,522,685	9,167,250
Real Estate | Construction and development
Loans and Leases Receivable Disclosure [Line Items]
Loans	2,082,688	1,326,371
Real Estate | Single family residential
Loans and Leases Receivable Disclosure [Line Items]
Loans	2,357,942	2,101,975
Real Estate | Other commercial
Loans and Leases Receivable Disclosure [Line Items]
Loans	7,082,055	5,738,904
Commercial
Loans and Leases Receivable Disclosure [Line Items]
Loans	2,830,999	2,160,760
Commercial | Commercial
Loans and Leases Receivable Disclosure [Line Items]
Loans	2,612,256	1,992,043
Commercial | Agricultural
Loans and Leases Receivable Disclosure [Line Items]
Loans	218,743	168,717
Other
Loans and Leases Receivable Disclosure [Line Items]
Loans	$ 362,284	$ 329,123