Purchased Loans - Purchased With Deteriorated Credit (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans, net	$ 10,757,503	$ 9,637,476
Purchased | Receivables Acquired with Deteriorated Credit Quality
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans, net		172,264
Purchased | Receivables Acquired with Deteriorated Credit Quality | Commercial, financial, agriculture
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans, net		29,538
Purchased | Receivables Acquired with Deteriorated Credit Quality | Real estate - construction
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans, net		863
Purchased | Receivables Acquired with Deteriorated Credit Quality | Real estate - 1-4 family mortgage
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans, net		35,543
Purchased | Receivables Acquired with Deteriorated Credit Quality | Real estate - commercial mortgage
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans, net		103,133
Purchased | Receivables Acquired with Deteriorated Credit Quality | Installment loans to individuals
Financing Receivable, Allowance for Credit Loss [Line Items]
Loans, net		$ 3,187