Loans Held for Investment (LHFI) and Allowance for Loan Losses, LHFI - Impaired Financing Receivables (Details) $ in Thousands	12 Months Ended
Dec. 31, 2019 USD ($)
Loan and Lease Receivables, Impaired [Abstract]
Total LHFI Unpaid Principal Balance	$ 47,289
Total LHFI With No Related Allowance Recorded	23,550
Total LHFI With an Allowance Recorded	17,667
Total LHFI Recorded Investment	41,217
Related Allowance	5,459
Average Recorded Investment	48,525
Commercial and Industrial Loans [Member]
Loan and Lease Receivables, Impaired [Abstract]
Total LHFI Unpaid Principal Balance	27,178
Total LHFI With No Related Allowance Recorded	19,374
Total LHFI With an Allowance Recorded	4,084
Total LHFI Recorded Investment	23,458
Related Allowance	707
Average Recorded Investment	27,088
Consumer Loans [Member]
Loan and Lease Receivables, Impaired [Abstract]
Total LHFI Unpaid Principal Balance	22
Total LHFI With No Related Allowance Recorded	0
Total LHFI With an Allowance Recorded	21
Total LHFI Recorded Investment	21
Related Allowance	0
Average Recorded Investment	11
State and Other Political Subdivision Loans [Member]
Loan and Lease Receivables, Impaired [Abstract]
Total LHFI Unpaid Principal Balance	4,079
Total LHFI With No Related Allowance Recorded	0
Total LHFI With an Allowance Recorded	4,079
Total LHFI Recorded Investment	4,079
Related Allowance	1,809
Average Recorded Investment	6,337
Other Loans [Member]
Loan and Lease Receivables, Impaired [Abstract]
Total LHFI Unpaid Principal Balance	1,207
Total LHFI With No Related Allowance Recorded	0
Total LHFI With an Allowance Recorded	784
Total LHFI Recorded Investment	784
Related Allowance	553
Average Recorded Investment	1,033
Loans Secured by Real Estate [Member] \| Construction, Land Development and Other Land [Member]
Loan and Lease Receivables, Impaired [Abstract]
Total LHFI Unpaid Principal Balance	926
Total LHFI With No Related Allowance Recorded	610
Total LHFI With an Allowance Recorded	16
Total LHFI Recorded Investment	626
Related Allowance	0
Average Recorded Investment	1,089
Loans Secured by Real Estate [Member] \| Secured by 1-4 Family Residential Properties [Member]
Loan and Lease Receivables, Impaired [Abstract]
Total LHFI Unpaid Principal Balance	6,513
Total LHFI With No Related Allowance Recorded	2,104
Total LHFI With an Allowance Recorded	3,360
Total LHFI Recorded Investment	5,464
Related Allowance	35
Average Recorded Investment	4,713
Loans Secured by Real Estate [Member] \| Secured by Nonfarm, Nonresidential Properties [Member]
Loan and Lease Receivables, Impaired [Abstract]
Total LHFI Unpaid Principal Balance	7,295
Total LHFI With No Related Allowance Recorded	1,462
Total LHFI With an Allowance Recorded	5,255
Total LHFI Recorded Investment	6,717
Related Allowance	2,355
Average Recorded Investment	8,096
Loans Secured by Real Estate [Member] \| Other Real Estate Secured [Member]
Loan and Lease Receivables, Impaired [Abstract]
Total LHFI Unpaid Principal Balance	69
Total LHFI With No Related Allowance Recorded	0
Total LHFI With an Allowance Recorded	68
Total LHFI Recorded Investment	68
Related Allowance	0
Average Recorded Investment	$ 158

Average amount of investment of impaired financing receivables with related allowance for credit losses and without a related allowance for credit losses.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 15
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5212-111524

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 17
-URI http://asc.fasb.org/extlink&oid=121611835&loc=d3e5258-111524

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 14A
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=121611835&loc=SL6953550-111524

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