LHFI and Allowance for Loan Losses, LHFI - Impact of Modifications Classified as Troubled Debt Restructurings (Details) - Troubled Debt Restructurings [Member] $ in Thousands	12 Months Ended
	Dec. 31, 2018 USD ($) Contract	Dec. 31, 2017 USD ($) Contract	Dec. 31, 2016 USD ($) Contract
Troubled Debt Restructurings [Abstract]
Number of Contracts | Contract	52	33	27
Pre-Modification Outstanding Recorded Investment	$ 30,878	$ 15,637	$ 12,162
Post-Modification Outstanding Recorded Investment	$ 29,328	$ 15,630	$ 12,106
Construction, Land Development and Other Land [Member]
Troubled Debt Restructurings [Abstract]
Number of Contracts | Contract	1	1	1
Pre-Modification Outstanding Recorded Investment	$ 22	$ 341	$ 14
Post-Modification Outstanding Recorded Investment	$ 22	$ 325	$ 14
Secured by 1-4 Family Residential Properties [Member]
Troubled Debt Restructurings [Abstract]
Number of Contracts | Contract	23	22	18
Pre-Modification Outstanding Recorded Investment	$ 2,102	$ 1,478	$ 1,386
Post-Modification Outstanding Recorded Investment	$ 1,660	$ 1,487	$ 1,391
Secured by Nonfarm, Nonresidential Properties [Member]
Troubled Debt Restructurings [Abstract]
Number of Contracts | Contract	2	1	2
Pre-Modification Outstanding Recorded Investment	$ 1,780	$ 426	$ 717
Post-Modification Outstanding Recorded Investment	$ 1,780	$ 426	$ 717
Commercial and Industrial Loans [Member]
Troubled Debt Restructurings [Abstract]
Number of Contracts | Contract	23	8	5
Pre-Modification Outstanding Recorded Investment	$ 26,970	$ 12,836	$ 10,043
Post-Modification Outstanding Recorded Investment	$ 25,862	$ 12,836	$ 9,982
Consumer Loans [Member]
Troubled Debt Restructurings [Abstract]
Number of Contracts | Contract	3		1
Pre-Modification Outstanding Recorded Investment	$ 4		$ 2
Post-Modification Outstanding Recorded Investment	$ 4		$ 2
Other Loans [Member]
Troubled Debt Restructurings [Abstract]
Number of Contracts | Contract		1
Pre-Modification Outstanding Recorded Investment		$ 556
Post-Modification Outstanding Recorded Investment		$ 556