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	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable Modifications [Line Items]
Nonaccrual	$ 61,624	$ 67,575
Construction, Land Development and Other Land [Member] \| Loans Secured by Real Estate [Member]
Financing Receivable Modifications [Line Items]
Nonaccrual	2,218	2,105
Secured by 1-4 Family Residential Properties [Member] \| Loans Secured by Real Estate [Member]
Financing Receivable Modifications [Line Items]
Nonaccrual	14,718	19,022
Secured by Nonfarm, Nonresidential Properties [Member] \| Loans Secured by Real Estate [Member]
Financing Receivable Modifications [Line Items]
Nonaccrual	9,621	12,608
Other Real Estate Secured [Member] \| Loans Secured by Real Estate [Member]
Financing Receivable Modifications [Line Items]
Nonaccrual	927	212
Commercial and Industrial Loans [Member]
Financing Receivable Modifications [Line Items]
Nonaccrual	23,938	33,338
Consumer Loans [Member]
Financing Receivable Modifications [Line Items]
Nonaccrual	205	135
Other Loans [Member]
Financing Receivable Modifications [Line Items]
Nonaccrual	1,402	155
Troubled Debt Restructurings [Member]
Financing Receivable Modifications [Line Items]
Accruing	11,484	660	$ 53
Nonaccrual	16,706	23,211	14,427
Total	28,190	23,871	14,480
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	0
Nonaccrual	24	199	405
Total	24	199	405
Troubled Debt Restructurings [Member] \| Secured by 1-4 Family Residential Properties [Member] \| Loans Secured by Real Estate [Member]
Financing Receivable Modifications [Line Items]
Accruing	743	51	0
Nonaccrual	3,125	3,140	2,873
Total	3,868	3,191	2,873
Troubled Debt Restructurings [Member] \| Secured by Nonfarm, Nonresidential Properties [Member] \| Loans Secured by Real Estate [Member]
Financing Receivable Modifications [Line Items]
Accruing	1,734	0	0
Nonaccrual	395	421	881
Total	2,129	421	881
Troubled Debt Restructurings [Member] \| Commercial and Industrial Loans [Member]
Financing Receivable Modifications [Line Items]
Accruing	9,007	53	53
Nonaccrual	12,620	19,434	10,266
Total	21,627	19,487	10,319
Troubled Debt Restructurings [Member] \| Consumer Loans [Member]
Financing Receivable Modifications [Line Items]
Accruing	0	0	0
Nonaccrual	2	17	2
Total	2	17	$ 2
Troubled Debt Restructurings [Member] \| Other Loans [Member]
Financing Receivable Modifications [Line Items]
Accruing	0	556
Nonaccrual	540	0
Total	$ 540	$ 556

Recorded investment in TDR's that are still accruing.

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

The amount of the outstanding recorded investment related to financing receivables that have been modified by troubled debt restructurings.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 40
-Section 50
-Paragraph 4
-URI http://asc.fasb.org/extlink&oid=82895541&loc=d3e18845-111554

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- Definition

Recorded investment in financing receivables that are on nonaccrual status as of the balance sheet date.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 7
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5111-111524

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