Non Purchased Loans - Summary of Non-Purchased Loans and Leases (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021	Jun. 30, 2021
Summary of loans
Gross loans	$ 10,608,904	$ 10,024,981
Unearned income	(5,160)	(4,067)
Loans, net of unearned income	10,603,744	10,020,914	$ 10,149,242
Commercial, financial, agricultural
Summary of loans
Gross loans	1,497,272	1,423,270
Loans, net of unearned income	1,497,272		1,634,633
Lease financing
Summary of loans
Gross loans	106,510	80,192
Loans, net of unearned income	101,350		74,003
Real estate – construction:
Summary of loans
Gross loans	1,126,363	1,104,896
Loans, net of unearned income	1,126,363		1,051,359
Real estate – construction: | Residential
Summary of loans
Gross loans	320,541	302,275
Real estate – construction: | Commercial
Summary of loans
Gross loans	805,822	802,621
Real estate – 1-4 family mortgage:
Summary of loans
Gross loans	3,030,083	2,724,246
Loans, net of unearned income	3,030,083		2,702,091
Real estate – 1-4 family mortgage: | Primary
Summary of loans
Gross loans	2,085,078	1,816,120
Real estate – 1-4 family mortgage: | Home equity
Summary of loans
Gross loans	488,048	474,604
Real estate – 1-4 family mortgage: | Rental/investment
Summary of loans
Gross loans	297,536	288,474
Real estate – 1-4 family mortgage: | Land development
Summary of loans
Gross loans	159,421	145,048
Real estate – commercial mortgage:
Summary of loans
Gross loans	4,717,513	4,549,037
Loans, net of unearned income	4,717,513		4,530,169
Real estate – commercial mortgage: | Land development
Summary of loans
Gross loans	126,795	128,739
Real estate – commercial mortgage: | Owner-occupied
Summary of loans
Gross loans	1,533,192	1,563,351
Real estate – commercial mortgage: | Non-owner occupied
Summary of loans
Gross loans	3,057,526	2,856,947
Installment loans to individuals
Summary of loans
Gross loans	131,163	143,340
Loans, net of unearned income	131,163		$ 156,987
Non purchased loans and leases
Summary of loans
Gross loans	9,697,276	9,015,078
Unearned income	(5,160)	(4,067)
Loans, net of unearned income	9,692,116	9,011,011
Non purchased loans and leases | Paycheck Protection Program
Summary of loans
Loans, net of unearned income	7,383	58,391
Non purchased loans and leases | Commercial, financial, agricultural
Summary of loans
Gross loans	1,405,642	1,332,962
Non purchased loans and leases | Lease financing
Summary of loans
Gross loans	106,510	80,192
Non purchased loans and leases | Real estate – construction:
Summary of loans
Gross loans	1,121,117	1,099,902
Non purchased loans and leases | Real estate – construction: | Residential
Summary of loans
Gross loans	319,287	300,988
Non purchased loans and leases | Real estate – construction: | Commercial
Summary of loans
Gross loans	801,830	798,914
Non purchased loans and leases | Real estate – 1-4 family mortgage:
Summary of loans
Gross loans	2,849,675	2,508,473
Non purchased loans and leases | Real estate – 1-4 family mortgage: | Primary
Summary of loans
Gross loans	1,976,535	1,682,050
Non purchased loans and leases | Real estate – 1-4 family mortgage: | Home equity
Summary of loans
Gross loans	443,045	423,108
Non purchased loans and leases | Real estate – 1-4 family mortgage: | Rental/investment
Summary of loans
Gross loans	279,621	268,245
Non purchased loans and leases | Real estate – 1-4 family mortgage: | Land development
Summary of loans
Gross loans	150,474	135,070
Non purchased loans and leases | Real estate – 1-4 family mortgage: | Land development
Summary of loans
Gross loans	150,474	135,070
Non purchased loans and leases | Real estate – commercial mortgage:
Summary of loans
Gross loans	4,110,671	3,885,984
Non purchased loans and leases | Real estate – commercial mortgage: | Owner-occupied
Summary of loans
Gross loans	1,323,106	1,329,219
Non purchased loans and leases | Real estate – commercial mortgage: | Non-owner occupied
Summary of loans
Gross loans	2,674,678	2,446,370
Non purchased loans and leases | Real estate – commercial mortgage: | Land development
Summary of loans
Gross loans	112,887	110,395
Non purchased loans and leases | Installment loans to individuals
Summary of loans
Gross loans	$ 103,661	$ 107,565