Loans and Allowance for Credit Losses - Financing Receivables Past Due (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Financing Receivable, Past Due [Line Items]
Loans	$ 30,297,871	$ 29,041,605
Commercial real estate - Owner occupied
Financing Receivable, Past Due [Line Items]
Loans	3,686,796	3,587,257
Commercial real estate - Non-owner occupied
Financing Receivable, Past Due [Line Items]
Loans	6,887,733	6,542,619
Consumer real estate – mortgage
Financing Receivable, Past Due [Line Items]
Loans	4,531,285	4,435,046
Construction and land development
Financing Receivable, Past Due [Line Items]
Loans	3,909,024	3,679,498
Commercial and industrial
Financing Receivable, Past Due [Line Items]
Loans	10,723,327	10,241,362
Consumer and other
Financing Receivable, Past Due [Line Items]
Loans	559,706	555,823
30-59 days past due
Financing Receivable, Past Due [Line Items]
Loans	30,975	35,840
30-59 days past due | Commercial real estate - Owner occupied
Financing Receivable, Past Due [Line Items]
Loans	1,075	2,112
30-59 days past due | Commercial real estate - Non-owner occupied
Financing Receivable, Past Due [Line Items]
Loans	405	359
30-59 days past due | Consumer real estate – mortgage
Financing Receivable, Past Due [Line Items]
Loans	12,803	13,635
30-59 days past due | Construction and land development
Financing Receivable, Past Due [Line Items]
Loans	52	221
30-59 days past due | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Loans	12,427	15,457
30-59 days past due | Consumer and other
Financing Receivable, Past Due [Line Items]
Loans	4,213	4,056
60-89 days past due
Financing Receivable, Past Due [Line Items]
Loans	8,883	16,249
60-89 days past due | Commercial real estate - Owner occupied
Financing Receivable, Past Due [Line Items]
Loans	0	615
60-89 days past due | Commercial real estate - Non-owner occupied
Financing Receivable, Past Due [Line Items]
Loans	272	48
60-89 days past due | Consumer real estate – mortgage
Financing Receivable, Past Due [Line Items]
Loans	1,325	83
60-89 days past due | Construction and land development
Financing Receivable, Past Due [Line Items]
Loans	0	102
60-89 days past due | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Loans	4,933	13,713
60-89 days past due | Consumer and other
Financing Receivable, Past Due [Line Items]
Loans	2,353	1,688
90 days or more past due
Financing Receivable, Past Due [Line Items]
Loans	20,324	22,218
90 days or more past due | Commercial real estate - Owner occupied
Financing Receivable, Past Due [Line Items]
Loans	1,789	1,139
90 days or more past due | Commercial real estate - Non-owner occupied
Financing Receivable, Past Due [Line Items]
Loans	206	1,681
90 days or more past due | Consumer real estate – mortgage
Financing Receivable, Past Due [Line Items]
Loans	4,844	9,094
90 days or more past due | Construction and land development
Financing Receivable, Past Due [Line Items]
Loans	130	130
90 days or more past due | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Loans	12,401	9,428
90 days or more past due | Consumer and other
Financing Receivable, Past Due [Line Items]
Loans	954	746
Financial Asset, Past Due
Financing Receivable, Past Due [Line Items]
Loans	60,182	74,307
Financial Asset, Past Due | Commercial real estate - Owner occupied
Financing Receivable, Past Due [Line Items]
Loans	2,864	3,866
Financial Asset, Past Due | Commercial real estate - Non-owner occupied
Financing Receivable, Past Due [Line Items]
Loans	883	2,088
Financial Asset, Past Due | Consumer real estate – mortgage
Financing Receivable, Past Due [Line Items]
Loans	18,972	22,812
Financial Asset, Past Due | Construction and land development
Financing Receivable, Past Due [Line Items]
Loans	182	453
Financial Asset, Past Due | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Loans	29,761	38,598
Financial Asset, Past Due | Consumer and other
Financing Receivable, Past Due [Line Items]
Loans	7,520	6,490
Financial Asset, Not Past Due
Financing Receivable, Past Due [Line Items]
Loans	30,237,689	28,967,298
Financial Asset, Not Past Due | Commercial real estate - Owner occupied
Financing Receivable, Past Due [Line Items]
Loans	3,683,932	3,583,391
Financial Asset, Not Past Due | Commercial real estate - Non-owner occupied
Financing Receivable, Past Due [Line Items]
Loans	6,886,850	6,540,531
Financial Asset, Not Past Due | Consumer real estate – mortgage
Financing Receivable, Past Due [Line Items]
Loans	4,512,313	4,412,234
Financial Asset, Not Past Due | Construction and land development
Financing Receivable, Past Due [Line Items]
Loans	3,908,842	3,679,045
Financial Asset, Not Past Due | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Loans	10,693,566	10,202,764
Financial Asset, Not Past Due | Consumer and other
Financing Receivable, Past Due [Line Items]
Loans	$ 552,186	$ 549,333