Purchased Loans - Summary of Purchased Loans (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	$ 10,020,914	$ 10,933,647
Purchased loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	1,009,903	1,514,107
Commercial, financial, agricultural
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	1,423,270	2,536,984
Commercial, financial, agricultural | Purchased loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	90,308	176,513
Real estate – construction:
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	1,104,896	858,104
Real estate – construction: | Purchased loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	4,994	30,952
Real estate – construction: | Purchased loans | Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	1,287	2,859
Real estate – construction: | Purchased loans | Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	3,707	28,093
Real Estate - 1-4 Family Mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	2,724,246	2,698,308
Real Estate - 1-4 Family Mortgage | Purchased loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	215,773	341,744
Real Estate - 1-4 Family Mortgage | Purchased loans | Primary
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	134,070	214,770
Real Estate - 1-4 Family Mortgage | Purchased loans | Home equity
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	51,496	80,392
Real Estate - 1-4 Family Mortgage | Purchased loans | Rental/investment
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	20,229	31,928
Real Estate - 1-4 Family Mortgage | Purchased loans | Land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	9,978	14,654
Real estate – commercial mortgage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	4,549,037	4,554,852
Real estate – commercial mortgage | Purchased loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	663,053	905,223
Real estate – commercial mortgage | Purchased loans | Land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	18,344	29,454
Real estate – commercial mortgage | Purchased loans | Owner-occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	234,132	323,041
Real estate – commercial mortgage | Purchased loans | Non-owner occupied
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	410,577	552,728
Real estate – commercial mortgage | Purchased loans | Land development
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	18,344	29,454
Installment loans to individuals
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	143,340	209,537
Installment loans to individuals | Purchased loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans, net of unearned income	$ 35,775	$ 59,675