Allowance for Credit Losses - Summary of Total Non Purchased and Purchased Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Jun. 30, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	$ 11,110,164		$ 10,024,981
Unearned income	(5,160)		(4,067)
Loans, net of unearned income	11,105,004		10,020,914	$ 10,016,824
Allowance for credit losses on loans	(174,356)	$ (166,131)	(164,171)	(170,038)	$ (172,354)	$ (176,144)
Loans, net	10,930,648		9,856,743
Non purchased loans and leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	10,265,000		9,015,078
Unearned income	(5,160)		(4,067)
Loans, net of unearned income	10,259,840		9,011,011
Non purchased loans and leases | Paycheck Protection Program
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	5,476		58,391
Commercial, financial, agricultural
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	1,513,091		1,423,270
Loans, net of unearned income	1,513,091			1,436,019
Allowance for credit losses on loans	(30,503)	(30,193)	(33,922)	(34,977)	(36,994)	(39,031)
Commercial, financial, agricultural | Non purchased loans and leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	1,435,275		1,332,962
Lease financing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	108,517		80,192
Loans, net of unearned income	103,357			79,215
Allowance for credit losses on loans	(2,314)	(1,802)	(1,486)	(1,570)	(1,511)	(1,624)
Lease financing | Non purchased loans and leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	108,517		80,192
Real estate – construction:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	1,215,056		1,104,896
Loans, net of unearned income	1,215,056			1,091,296
Allowance for credit losses on loans	(18,744)	(17,290)	(16,419)	(16,169)	(15,729)	(16,047)
Real estate – construction: | Non purchased loans and leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	1,208,308		1,099,902
Real estate – construction: | Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	359,754		302,275
Real estate – construction: | Residential | Non purchased loans and leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	359,367		300,988
Real estate – construction: | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	855,302		802,621
Real estate – construction: | Commercial | Non purchased loans and leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	848,941		798,914
Real estate – 1-4 family mortgage:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	3,127,889		2,724,246
Loans, net of unearned income	3,127,889			2,724,743
Allowance for credit losses on loans	(43,532)	(41,910)	(32,356)	(32,181)	(31,303)	(32,165)
Real estate – 1-4 family mortgage: | Non purchased loans and leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	2,956,801		2,508,473
Real estate – 1-4 family mortgage: | Primary
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	2,144,119		1,816,120
Real estate – 1-4 family mortgage: | Primary | Non purchased loans and leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	2,041,885		1,682,050
Real estate – 1-4 family mortgage: | Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	499,626		474,604
Real estate – 1-4 family mortgage: | Home equity | Non purchased loans and leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	456,765		423,108
Real estate – 1-4 family mortgage: | Rental/investment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	322,844		288,474
Real estate – 1-4 family mortgage: | Rental/investment | Non purchased loans and leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	306,165		268,245
Real estate – 1-4 family mortgage: | Land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	161,300		145,048
Real estate – 1-4 family mortgage: | Land development | Non purchased loans and leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	151,986		135,070
Real estate – commercial mortgage:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	5,016,665		4,549,037
Loans, net of unearned income	5,016,665			4,535,730
Allowance for credit losses on loans	(69,267)	(64,373)	(68,940)	(73,895)	(74,893)	(76,127)
Real estate – commercial mortgage: | Non purchased loans and leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	4,451,853		3,885,984
Real estate – commercial mortgage: | Land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	133,597		128,739
Real estate – commercial mortgage: | Owner-occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	1,562,952		1,563,351
Real estate – commercial mortgage: | Owner-occupied | Non purchased loans and leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	1,368,196		1,329,219
Real estate – commercial mortgage: | Non-owner occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	3,320,116		2,856,947
Real estate – commercial mortgage: | Non-owner occupied | Non purchased loans and leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	2,963,631		2,446,370
Installment loans to individuals
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	128,946		143,340
Loans, net of unearned income	128,946			149,821
Allowance for credit losses on loans	(9,996)	$ (10,563)	(11,048)	$ (11,246)	$ (11,924)	$ (11,150)
Installment loans to individuals | Non purchased loans and leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	$ 104,246		$ 107,565