Purchased Loans - Summary of Purchased Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Dec. 31, 2021	Sep. 30, 2021
Summary of loans
Gross loans	$ 11,110,164	$ 10,024,981
Loans, net of unearned income	11,105,004	10,020,914	$ 10,016,824
Commercial, financial, agricultural
Summary of loans
Gross loans	1,513,091	1,423,270
Loans, net of unearned income	1,513,091		1,436,019
Real estate – construction:
Summary of loans
Gross loans	1,215,056	1,104,896
Loans, net of unearned income	1,215,056		1,091,296
Real estate – construction: | Residential
Summary of loans
Gross loans	359,754	302,275
Real estate – construction: | Commercial
Summary of loans
Gross loans	855,302	802,621
Real estate – 1-4 family mortgage:
Summary of loans
Gross loans	3,127,889	2,724,246
Loans, net of unearned income	3,127,889		2,724,743
Real estate – 1-4 family mortgage: | Primary
Summary of loans
Gross loans	2,144,119	1,816,120
Real estate – 1-4 family mortgage: | Home equity
Summary of loans
Gross loans	499,626	474,604
Real estate – 1-4 family mortgage: | Rental/investment
Summary of loans
Gross loans	322,844	288,474
Real estate – 1-4 family mortgage: | Land development
Summary of loans
Gross loans	161,300	145,048
Real estate – commercial mortgage:
Summary of loans
Gross loans	5,016,665	4,549,037
Loans, net of unearned income	5,016,665		4,535,730
Real estate – commercial mortgage: | Land development
Summary of loans
Gross loans	133,597	128,739
Real estate – commercial mortgage: | Owner-occupied
Summary of loans
Gross loans	1,562,952	1,563,351
Real estate – commercial mortgage: | Non-owner occupied
Summary of loans
Gross loans	3,320,116	2,856,947
Installment loans to individuals
Summary of loans
Gross loans	128,946	143,340
Loans, net of unearned income	128,946		$ 149,821
Purchased loans
Summary of loans
Loans, net of unearned income	845,164	1,009,903
Purchased loans | Commercial, financial, agricultural
Summary of loans
Gross loans	77,816	90,308
Loans, net of unearned income	77,816	90,308
Purchased loans | Real estate – construction:
Summary of loans
Gross loans	6,748	4,994
Loans, net of unearned income	6,748	4,994
Purchased loans | Real estate – construction: | Residential
Summary of loans
Gross loans	387	1,287
Loans, net of unearned income	387	1,287
Purchased loans | Real estate – construction: | Commercial
Summary of loans
Gross loans	6,361	3,707
Loans, net of unearned income	6,361	3,707
Purchased loans | Real estate – 1-4 family mortgage:
Summary of loans
Gross loans	171,088	215,773
Loans, net of unearned income	171,088	215,773
Purchased loans | Real estate – 1-4 family mortgage: | Primary
Summary of loans
Gross loans	102,234	134,070
Loans, net of unearned income	102,234	134,070
Purchased loans | Real estate – 1-4 family mortgage: | Home equity
Summary of loans
Gross loans	42,861	51,496
Loans, net of unearned income	42,861	51,496
Purchased loans | Real estate – 1-4 family mortgage: | Rental/investment
Summary of loans
Gross loans	16,679	20,229
Loans, net of unearned income	16,679	20,229
Purchased loans | Real estate – 1-4 family mortgage: | Land development
Summary of loans
Gross loans	9,314	9,978
Loans, net of unearned income	9,314	9,978
Purchased loans | Real estate – commercial mortgage:
Summary of loans
Gross loans	564,812	663,053
Loans, net of unearned income	564,812	663,053
Purchased loans | Real estate – commercial mortgage: | Land development
Summary of loans
Loans, net of unearned income	13,571	18,344
Purchased loans | Real estate – commercial mortgage: | Owner-occupied
Summary of loans
Gross loans	194,756	234,132
Loans, net of unearned income	194,756	234,132
Purchased loans | Real estate – commercial mortgage: | Non-owner occupied
Summary of loans
Gross loans	356,485	410,577
Loans, net of unearned income	356,485	410,577
Purchased loans | Real estate – commercial mortgage: | Land development
Summary of loans
Gross loans	13,571	18,344
Purchased loans | Installment loans to individuals
Summary of loans
Gross loans	24,700	35,775
Loans, net of unearned income	$ 24,700	$ 35,775