LHFI and Allowance for Loan Losses, LHFI - Impaired Financing Receivables (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Loan and Lease Receivables, Impaired [Abstract]
Total LHFI Unpaid Principal Balance	$ 62,921	$ 60,387
Total LHFI With No Related Allowance Recorded	25,553	42,674
Total LHFI With an Allowance Recorded	30,282	6,262
Total LHFI Carrying Amount	55,835	48,936
Related Allowance	6,354	1,743
Average Recorded Investment	46,920	38,005
Commercial and Industrial Loans [Member]
Loan and Lease Receivables, Impaired [Abstract]
Total LHFI Unpaid Principal Balance	37,786	36,874
Total LHFI With No Related Allowance Recorded	12,893	31,281
Total LHFI With an Allowance Recorded	17,824	518
Total LHFI Carrying Amount	30,717	31,799
Related Allowance	4,334	131
Average Recorded Investment	26,725	22,734
Consumer Loans [Member]
Loan and Lease Receivables, Impaired [Abstract]
Total LHFI Unpaid Principal Balance	2	17
Total LHFI With No Related Allowance Recorded	0	0
Total LHFI With an Allowance Recorded	2	17
Total LHFI Carrying Amount	2	17
Related Allowance	0	0
Average Recorded Investment	6	9
State and Other Political Subdivision Loans [Member]
Loan and Lease Receivables, Impaired [Abstract]
Total LHFI Unpaid Principal Balance	8,688	0
Total LHFI With No Related Allowance Recorded	4,079	0
Total LHFI With an Allowance Recorded	4,516	0
Total LHFI Carrying Amount	8,595	0
Related Allowance	516	0
Average Recorded Investment	4,297	0
Other Loans [Member]
Loan and Lease Receivables, Impaired [Abstract]
Total LHFI Unpaid Principal Balance	1,418	556
Total LHFI With No Related Allowance Recorded	230	0
Total LHFI With an Allowance Recorded	1,052	556
Total LHFI Carrying Amount	1,282	556
Related Allowance	1,052	41
Average Recorded Investment	804	325
Loans Secured by Real Estate [Member] | Construction, Land Development and Other Land [Member]
Loan and Lease Receivables, Impaired [Abstract]
Total LHFI Unpaid Principal Balance	1,794	1,704
Total LHFI With No Related Allowance Recorded	1,528	1,206
Total LHFI With an Allowance Recorded	24	199
Total LHFI Carrying Amount	1,552	1,405
Related Allowance	0	75
Average Recorded Investment	1,738	1,923
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	4,951	6,031
Total LHFI With No Related Allowance Recorded	95	160
Total LHFI With an Allowance Recorded	3,868	4,576
Total LHFI Carrying Amount	3,963	4,736
Related Allowance	39	1,331
Average Recorded Investment	4,328	4,693
Loans Secured by Real Estate [Member] | Secured by Nonfarm, Nonresidential Properties [Member]
Loan and Lease Receivables, Impaired [Abstract]
Total LHFI Unpaid Principal Balance	8,282	15,205
Total LHFI With No Related Allowance Recorded	6,728	10,027
Total LHFI With an Allowance Recorded	2,748	396
Total LHFI Carrying Amount	9,476	10,423
Related Allowance	413	165
Average Recorded Investment	8,898	8,321
Loans Secured by Real Estate [Member] | Other Real Estate Secured [Member]
Loan and Lease Receivables, Impaired [Abstract]
Total LHFI Unpaid Principal Balance	0	0
Total LHFI With No Related Allowance Recorded	0	0
Total LHFI With an Allowance Recorded	248	0
Total LHFI Carrying Amount	248	0
Related Allowance	0	0
Average Recorded Investment	$ 124	$ 0