Loans and Allowance for Credit Losses - Financing Receivables Past Due (Details) - USD ($) $ in Thousands	Mar. 31, 2024	Dec. 31, 2023
Financing Receivable, Past Due [Line Items]
Loans	$ 33,162,873	$ 32,676,091
Commercial real estate - owner occupied
Financing Receivable, Past Due [Line Items]
Loans	4,044,973	4,044,896
Commercial real estate - non-owner occupied
Financing Receivable, Past Due [Line Items]
Loans	8,063,642	7,535,494
Consumer real estate – mortgage
Financing Receivable, Past Due [Line Items]
Loans	4,828,416	4,851,531
Construction and land development
Financing Receivable, Past Due [Line Items]
Loans	3,818,334	4,041,081
Commercial and industrial
Financing Receivable, Past Due [Line Items]
Loans	11,893,198	11,666,691
Consumer and other
Financing Receivable, Past Due [Line Items]
Loans	514,310	536,398
30-59 days past due
Financing Receivable, Past Due [Line Items]
Loans	42,883	83,937
30-59 days past due | Commercial real estate - owner occupied
Financing Receivable, Past Due [Line Items]
Loans	3,538	1,671
30-59 days past due | Commercial real estate - non-owner occupied
Financing Receivable, Past Due [Line Items]
Loans	616	40,577
30-59 days past due | Consumer real estate – mortgage
Financing Receivable, Past Due [Line Items]
Loans	16,928	21,585
30-59 days past due | Construction and land development
Financing Receivable, Past Due [Line Items]
Loans	1,342	621
30-59 days past due | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Loans	16,667	14,197
30-59 days past due | Consumer and other
Financing Receivable, Past Due [Line Items]
Loans	3,792	5,286
60-89 days past due
Financing Receivable, Past Due [Line Items]
Loans	21,739	32,465
60-89 days past due | Commercial real estate - owner occupied
Financing Receivable, Past Due [Line Items]
Loans	6,231	507
60-89 days past due | Commercial real estate - non-owner occupied
Financing Receivable, Past Due [Line Items]
Loans	700	489
60-89 days past due | Consumer real estate – mortgage
Financing Receivable, Past Due [Line Items]
Loans	5,327	1,352
60-89 days past due | Construction and land development
Financing Receivable, Past Due [Line Items]
Loans	384	28
60-89 days past due | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Loans	7,202	28,221
60-89 days past due | Consumer and other
Financing Receivable, Past Due [Line Items]
Loans	1,895	1,868
90 days or more past due
Financing Receivable, Past Due [Line Items]
Loans	69,388	33,369
90 days or more past due | Commercial real estate - owner occupied
Financing Receivable, Past Due [Line Items]
Loans	2,601	3,398
90 days or more past due | Commercial real estate - non-owner occupied
Financing Receivable, Past Due [Line Items]
Loans	38,654	153
90 days or more past due | Consumer real estate – mortgage
Financing Receivable, Past Due [Line Items]
Loans	6,755	10,824
90 days or more past due | Construction and land development
Financing Receivable, Past Due [Line Items]
Loans	107	608
90 days or more past due | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Loans	20,120	16,890
90 days or more past due | Consumer and other
Financing Receivable, Past Due [Line Items]
Loans	1,151	1,496
Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Loans	134,010	149,771
Financial Asset, Past Due | Commercial real estate - owner occupied
Financing Receivable, Past Due [Line Items]
Loans	12,370	5,576
Financial Asset, Past Due | Commercial real estate - non-owner occupied
Financing Receivable, Past Due [Line Items]
Loans	39,970	41,219
Financial Asset, Past Due | Consumer real estate – mortgage
Financing Receivable, Past Due [Line Items]
Loans	29,010	33,761
Financial Asset, Past Due | Construction and land development
Financing Receivable, Past Due [Line Items]
Loans	1,833	1,257
Financial Asset, Past Due | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Loans	43,989	59,308
Financial Asset, Past Due | Consumer and other
Financing Receivable, Past Due [Line Items]
Loans	6,838	8,650
Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Loans	33,028,863	32,526,320
Financial Asset, Not Past Due | Commercial real estate - owner occupied
Financing Receivable, Past Due [Line Items]
Loans	4,032,603	4,039,320
Financial Asset, Not Past Due | Commercial real estate - non-owner occupied
Financing Receivable, Past Due [Line Items]
Loans	8,023,672	7,494,275
Financial Asset, Not Past Due | Consumer real estate – mortgage
Financing Receivable, Past Due [Line Items]
Loans	4,799,406	4,817,770
Financial Asset, Not Past Due | Construction and land development
Financing Receivable, Past Due [Line Items]
Loans	3,816,501	4,039,824
Financial Asset, Not Past Due | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Loans	11,849,209	11,607,383
Financial Asset, Not Past Due | Consumer and other
Financing Receivable, Past Due [Line Items]
Loans	$ 507,472	$ 527,748