Loans Held for Investment (LHFI) and Allowance for Loan Losses, LHFI - Troubled Debt Restructuring Related to Loans Held for Investment, Excluding Covered Loans, by Loan Type (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021	Jun. 30, 2021
Financing Receivable Modifications [Line Items]
Nonaccrual	$ 62,052	$ 62,698
Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member]
Financing Receivable Modifications [Line Items]
Nonaccrual	4,399	5,878
Other Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable Modifications [Line Items]
Nonaccrual	3,547	3,418
Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable Modifications [Line Items]
Nonaccrual	11,668	12,508
Secured by 1-4 Family Residential Properties [Member] | Other Loans Secured by Real Estate [Member]
Financing Receivable Modifications [Line Items]
Nonaccrual	13,618	12,775
Commercial and Industrial Loans [Member]
Financing Receivable Modifications [Line Items]
Nonaccrual	16,869	19,328
Consumer Loans [Member]
Financing Receivable Modifications [Line Items]
Nonaccrual	126	117
State and Other Political Subdivision Loans [Member]
Financing Receivable Modifications [Line Items]
Nonaccrual	3,196	3,664
Other Commercial Loans [Member]
Financing Receivable Modifications [Line Items]
Nonaccrual	227	4,860
Other Real Estate Secured [Member] | Loans Secured by Real Estate [Member]
Financing Receivable Modifications [Line Items]
Nonaccrual	782	$ 150
Troubled Debt Restructurings [Member]
Financing Receivable Modifications [Line Items]
Accruing	640		$ 2,552
Nonaccrual	19,303		22,563
Total	19,943		25,115
Troubled Debt Restructurings [Member] | Construction, Land Development and Other Land [Member] | Loans Secured by Real Estate [Member]
Financing Receivable Modifications [Line Items]
Accruing	0		0
Nonaccrual	3,981		5,593
Total	3,981		5,593
Troubled Debt Restructurings [Member] | Other Secured by 1-4 Family Residential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable Modifications [Line Items]
Accruing	40		0
Nonaccrual	873		1,160
Total	913		1,160
Troubled Debt Restructurings [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Loans Secured by Real Estate [Member]
Financing Receivable Modifications [Line Items]
Accruing	0		0
Nonaccrual	7,892		3,090
Total	7,892		3,090
Troubled Debt Restructurings [Member] | Secured by 1-4 Family Residential Properties [Member] | Other Loans Secured by Real Estate [Member]
Financing Receivable Modifications [Line Items]
Accruing	100		52
Nonaccrual	3,361		2,414
Total	3,461		2,466
Troubled Debt Restructurings [Member] | Commercial and Industrial Loans [Member]
Financing Receivable Modifications [Line Items]
Accruing	500		2,500
Nonaccrual	54		1,608
Total	554		4,108
Troubled Debt Restructurings [Member] | Consumer Loans [Member]
Financing Receivable Modifications [Line Items]
Accruing	0		0
Nonaccrual	2		12
Total	2		12
Troubled Debt Restructurings [Member] | State and Other Political Subdivision Loans [Member]
Financing Receivable Modifications [Line Items]
Accruing	0		0
Nonaccrual	3,019		3,677
Total	3,019		3,677
Troubled Debt Restructurings [Member] | Other Commercial Loans [Member]
Financing Receivable Modifications [Line Items]
Accruing	0		0
Nonaccrual	36		5,009
Total	36		$ 5,009
Troubled Debt Restructurings [Member] | Other Real Estate Secured [Member] | Loans Secured by Real Estate [Member]
Financing Receivable Modifications [Line Items]
Accruing	0
Nonaccrual	85
Total	$ 85