Allowance for Credit Losses - Summary of Total Non Purchased and Purchased Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
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
Allowance for credit losses	(166,131)	$ (166,468)	(164,171)	(172,354)	$ (173,106)	$ (176,144)
Loans, net	10,437,613		9,856,743
Non purchased loans and leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
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
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	7,383		58,391
Commercial, financial, agricultural
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	1,497,272		1,423,270
Loans, net of unearned income	1,497,272			1,634,633
Allowance for credit losses	(30,193)	(33,606)	(33,922)	(36,994)	(37,592)	(39,031)
Commercial, financial, agricultural | Non purchased loans and leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	1,405,642		1,332,962
Lease financing
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	106,510		80,192
Loans, net of unearned income	101,350			74,003
Allowance for credit losses	(1,802)	(1,582)	(1,486)	(1,511)	(1,546)	(1,624)
Lease financing | Non purchased loans and leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	106,510		80,192
Real estate – construction:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	1,126,363		1,104,896
Loans, net of unearned income	1,126,363			1,051,359
Allowance for credit losses	(17,290)	(18,411)	(16,419)	(15,729)	(14,977)	(16,047)
Real estate – construction: | Non purchased loans and leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	1,121,117		1,099,902
Real estate – construction: | Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	320,541		302,275
Real estate – construction: | Residential | Non purchased loans and leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	319,287		300,988
Real estate – construction: | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	805,822		802,621
Real estate – construction: | Commercial | Non purchased loans and leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	801,830		798,914
Real estate – 1-4 family mortgage:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	3,030,083		2,724,246
Loans, net of unearned income	3,030,083			2,702,091
Allowance for credit losses	(41,910)	(36,848)	(32,356)	(31,303)	(31,694)	(32,165)
Real estate – 1-4 family mortgage: | Non purchased loans and leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	2,849,675		2,508,473
Real estate – 1-4 family mortgage: | Primary
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	2,085,078		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	1,976,535		1,682,050
Real estate – 1-4 family mortgage: | Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	488,048		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	443,045		423,108
Real estate – 1-4 family mortgage: | Rental/investment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	297,536		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	279,621		268,245
Real estate – 1-4 family mortgage: | Land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	159,421		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	150,474		135,070
Real estate – commercial mortgage:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	4,717,513		4,549,037
Loans, net of unearned income	4,717,513			4,530,169
Allowance for credit losses	(64,373)	(65,231)	(68,940)	(74,893)	(76,225)	(76,127)
Real estate – commercial mortgage: | Non purchased loans and leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	4,110,671		3,885,984
Real estate – commercial mortgage: | Land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	126,795		128,739
Real estate – commercial mortgage: | Owner-occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	1,533,192		1,563,351
Real estate – commercial mortgage: | Owner-occupied | Non purchased loans and leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	1,323,106		1,329,219
Real estate – commercial mortgage: | Non-owner occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	3,057,526		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	2,674,678		2,446,370
Installment loans to individuals
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	131,163		143,340
Loans, net of unearned income	131,163			156,987
Allowance for credit losses	(10,563)	$ (10,790)	(11,048)	$ (11,924)	$ (11,072)	$ (11,150)
Installment loans to individuals | Non purchased loans and leases
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gross loans	$ 103,661		$ 107,565