Loans and Allowance for Credit Losses - Financing Receivables Past Due (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Financing Receivable, Past Due [Line Items]
Loans	$ 26,333,096	$ 23,414,262
Commercial real estate - Owner occupied
Financing Receivable, Past Due [Line Items]
Loans	3,243,018	3,048,822
Commercial real estate - Non-owner occupied
Financing Receivable, Past Due [Line Items]
Loans	5,861,596	5,221,704
Consumer real estate – mortgage
Financing Receivable, Past Due [Line Items]
Loans	4,047,051	3,680,684
Construction and land development
Financing Receivable, Past Due [Line Items]
Loans	3,386,866	2,903,017
Commercial and industrial
Financing Receivable, Past Due [Line Items]
Loans	9,295,808	8,074,546
Consumer and other
Financing Receivable, Past Due [Line Items]
Loans	498,757	485,489
30-59 days past due
Financing Receivable, Past Due [Line Items]
Loans	12,714	17,573
30-59 days past due | Commercial real estate - Owner occupied
Financing Receivable, Past Due [Line Items]
Loans	650	727
30-59 days past due | Commercial real estate - Non-owner occupied
Financing Receivable, Past Due [Line Items]
Loans	631	1,434
30-59 days past due | Consumer real estate – mortgage
Financing Receivable, Past Due [Line Items]
Loans	1,834	8,710
30-59 days past due | Construction and land development
Financing Receivable, Past Due [Line Items]
Loans	4	61
30-59 days past due | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Loans	7,064	4,926
30-59 days past due | Consumer and other
Financing Receivable, Past Due [Line Items]
Loans	2,531	1,715
60-89 days past due
Financing Receivable, Past Due [Line Items]
Loans	15,357	3,367
60-89 days past due | Commercial real estate - Owner occupied
Financing Receivable, Past Due [Line Items]
Loans	756	0
60-89 days past due | Commercial real estate - Non-owner occupied
Financing Receivable, Past Due [Line Items]
Loans	0	0
60-89 days past due | Consumer real estate – mortgage
Financing Receivable, Past Due [Line Items]
Loans	9,961	122
60-89 days past due | Construction and land development
Financing Receivable, Past Due [Line Items]
Loans	0	0
60-89 days past due | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Loans	3,074	2,677
60-89 days past due | Consumer and other
Financing Receivable, Past Due [Line Items]
Loans	1,566	568
90 days or more past due
Financing Receivable, Past Due [Line Items]
Loans	13,849	15,331
90 days or more past due | Commercial real estate - Owner occupied
Financing Receivable, Past Due [Line Items]
Loans	2,564	2,426
90 days or more past due | Commercial real estate - Non-owner occupied
Financing Receivable, Past Due [Line Items]
Loans	1,723	645
90 days or more past due | Consumer real estate – mortgage
Financing Receivable, Past Due [Line Items]
Loans	5,604	4,450
90 days or more past due | Construction and land development
Financing Receivable, Past Due [Line Items]
Loans	200	127
90 days or more past due | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Loans	3,260	7,311
90 days or more past due | Consumer and other
Financing Receivable, Past Due [Line Items]
Loans	498	372
Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Loans	41,920	36,271
Financial Asset, Past Due | Commercial real estate - Owner occupied
Financing Receivable, Past Due [Line Items]
Loans	3,970	3,153
Financial Asset, Past Due | Commercial real estate - Non-owner occupied
Financing Receivable, Past Due [Line Items]
Loans	2,354	2,079
Financial Asset, Past Due | Consumer real estate – mortgage
Financing Receivable, Past Due [Line Items]
Loans	17,399	13,282
Financial Asset, Past Due | Construction and land development
Financing Receivable, Past Due [Line Items]
Loans	204	188
Financial Asset, Past Due | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Loans	13,398	14,914
Financial Asset, Past Due | Consumer and other
Financing Receivable, Past Due [Line Items]
Loans	4,595	2,655
Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Loans	26,291,176	23,377,991
Financial Asset, Not Past Due | Commercial real estate - Owner occupied
Financing Receivable, Past Due [Line Items]
Loans	3,239,048	3,045,669
Financial Asset, Not Past Due | Commercial real estate - Non-owner occupied
Financing Receivable, Past Due [Line Items]
Loans	5,859,242	5,219,625
Financial Asset, Not Past Due | Consumer real estate – mortgage
Financing Receivable, Past Due [Line Items]
Loans	4,029,652	3,667,402
Financial Asset, Not Past Due | Construction and land development
Financing Receivable, Past Due [Line Items]
Loans	3,386,662	2,902,829
Financial Asset, Not Past Due | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Loans	9,282,410	8,059,632
Financial Asset, Not Past Due | Consumer and other
Financing Receivable, Past Due [Line Items]
Loans	$ 494,162	$ 482,834