Loans Held for Investment (LHFI) and Allowance for Loan Losses, LHFI - Summary of Amortized Cost Basis of Loans by Credit Quality Indicator (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	$ 1,343,412
Term Loans by Origination Year, 2019	2,167,880
Term Loans by Origination Year, 2018	1,544,809
Term Loans by Origination Year, 2017	953,747
Term Loans by Origination Year, 2016	917,347
Term Loans by Origination Year, Prior to 2016	1,447,202
Financing Receivable, Revolving Loans	1,285,409
Financing Receivable, before Allowance for Credit Loss	9,659,806
Commercial LHFI [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	1,141,257
Term Loans by Origination Year, 2019	1,821,629
Term Loans by Origination Year, 2018	1,276,005
Term Loans by Origination Year, 2017	823,097
Term Loans by Origination Year, 2016	779,143
Term Loans by Origination Year, Prior to 2016	1,023,985
Financing Receivable, Revolving Loans	863,338
Financing Receivable, before Allowance for Credit Loss	7,728,454	$ 7,348,158
Commercial LHFI [Member] \| Pass - RR 1 through RR 6 [Member]
Financing Receivable Recorded Investment [Line Items]
Financing Receivable, before Allowance for Credit Loss		7,178,617
Commercial LHFI [Member] \| Special Mention - RR 7 [Member]
Financing Receivable Recorded Investment [Line Items]
Financing Receivable, before Allowance for Credit Loss		9,049
Commercial LHFI [Member] \| Substandard - RR 8 [Member]
Financing Receivable Recorded Investment [Line Items]
Financing Receivable, before Allowance for Credit Loss		159,163
Commercial LHFI [Member] \| Doubtful - RR 9 [Member]
Financing Receivable Recorded Investment [Line Items]
Financing Receivable, before Allowance for Credit Loss		1,329
Commercial LHFI [Member] \| Commercial and Industrial Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	313,012
Term Loans by Origination Year, 2019	284,333
Term Loans by Origination Year, 2018	131,371
Term Loans by Origination Year, 2017	96,040
Term Loans by Origination Year, 2016	83,208
Term Loans by Origination Year, Prior to 2016	59,387
Financing Receivable, Revolving Loans	445,904
Financing Receivable, before Allowance for Credit Loss	1,413,255	1,477,896
Commercial LHFI [Member] \| Commercial and Industrial Loans [Member] \| Pass - RR 1 through RR 6 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	301,484
Term Loans by Origination Year, 2019	281,419
Term Loans by Origination Year, 2018	115,890
Term Loans by Origination Year, 2017	95,696
Term Loans by Origination Year, 2016	82,537
Term Loans by Origination Year, Prior to 2016	56,802
Financing Receivable, Revolving Loans	434,958
Financing Receivable, before Allowance for Credit Loss	1,368,786	1,407,837
Commercial LHFI [Member] \| Commercial and Industrial Loans [Member] \| Special Mention - RR 7 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	850
Financing Receivable, Revolving Loans	833
Financing Receivable, before Allowance for Credit Loss	1,683	909
Commercial LHFI [Member] \| Commercial and Industrial Loans [Member] \| Substandard - RR 8 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	10,630
Term Loans by Origination Year, 2019	2,512
Term Loans by Origination Year, 2018	15,481
Term Loans by Origination Year, 2017	344
Term Loans by Origination Year, 2016	628
Term Loans by Origination Year, Prior to 2016	2,581
Financing Receivable, Revolving Loans	10,089
Financing Receivable, before Allowance for Credit Loss	42,265	68,262
Commercial LHFI [Member] \| Commercial and Industrial Loans [Member] \| Doubtful - RR 9 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	48
Term Loans by Origination Year, 2019	402
Term Loans by Origination Year, 2016	43
Term Loans by Origination Year, Prior to 2016	4
Financing Receivable, Revolving Loans	24
Financing Receivable, before Allowance for Credit Loss	521	888
Commercial LHFI [Member] \| State and Other Political Subdivision Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	85,513
Term Loans by Origination Year, 2019	109,844
Term Loans by Origination Year, 2018	54,240
Term Loans by Origination Year, 2017	119,871
Term Loans by Origination Year, 2016	144,165
Term Loans by Origination Year, Prior to 2016	417,005
Financing Receivable, Revolving Loans	898
Financing Receivable, before Allowance for Credit Loss	931,536	967,944
Commercial LHFI [Member] \| State and Other Political Subdivision Loans [Member] \| Pass - RR 1 through RR 6 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	85,513
Term Loans by Origination Year, 2019	109,844
Term Loans by Origination Year, 2018	54,240
Term Loans by Origination Year, 2017	119,532
Term Loans by Origination Year, 2016	144,165
Term Loans by Origination Year, Prior to 2016	408,276
Financing Receivable, Revolving Loans	898
Financing Receivable, before Allowance for Credit Loss	922,468	957,948
Commercial LHFI [Member] \| State and Other Political Subdivision Loans [Member] \| Special Mention - RR 7 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, Prior to 2016	4,000
Financing Receivable, before Allowance for Credit Loss	4,000	4,650
Commercial LHFI [Member] \| State and Other Political Subdivision Loans [Member] \| Substandard - RR 8 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2017	339
Term Loans by Origination Year, Prior to 2016	4,729
Financing Receivable, before Allowance for Credit Loss	5,068	5,346
Commercial LHFI [Member] \| Other Commercial Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	74,403
Term Loans by Origination Year, 2019	86,158
Term Loans by Origination Year, 2018	29,571
Term Loans by Origination Year, 2017	14,866
Term Loans by Origination Year, 2016	59,015
Term Loans by Origination Year, Prior to 2016	54,138
Financing Receivable, Revolving Loans	246,295
Financing Receivable, before Allowance for Credit Loss	564,446
Commercial LHFI [Member] \| Other Commercial Loans [Member] \| Pass - RR 1 through RR 6 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	66,388
Term Loans by Origination Year, 2019	83,965
Term Loans by Origination Year, 2018	28,885
Term Loans by Origination Year, 2017	14,821
Term Loans by Origination Year, 2016	57,952
Term Loans by Origination Year, Prior to 2016	54,114
Financing Receivable, Revolving Loans	224,792
Financing Receivable, before Allowance for Credit Loss	530,917
Commercial LHFI [Member] \| Other Commercial Loans [Member] \| Special Mention - RR 7 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	7,917
Financing Receivable, Revolving Loans	11,833
Financing Receivable, before Allowance for Credit Loss	19,750
Commercial LHFI [Member] \| Other Commercial Loans [Member] \| Substandard - RR 8 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	98
Term Loans by Origination Year, 2019	2,190
Term Loans by Origination Year, 2018	686
Term Loans by Origination Year, 2017	45
Term Loans by Origination Year, 2016	1,063
Term Loans by Origination Year, Prior to 2016	1
Financing Receivable, Revolving Loans	9,670
Financing Receivable, before Allowance for Credit Loss	13,753
Commercial LHFI [Member] \| Other Commercial Loans [Member] \| Doubtful - RR 9 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2019	3
Term Loans by Origination Year, Prior to 2016	23
Financing Receivable, before Allowance for Credit Loss	26
Commercial LHFI [Member] \| Loans Secured by Real Estate [Member] \| Construction, Land Development and Other Land [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	172,535
Term Loans by Origination Year, 2019	146,498
Term Loans by Origination Year, 2018	37,169
Term Loans by Origination Year, 2017	5,460
Term Loans by Origination Year, 2016	4,251
Term Loans by Origination Year, Prior to 2016	5,260
Financing Receivable, Revolving Loans	37,106
Financing Receivable, before Allowance for Credit Loss	408,279
Commercial LHFI [Member] \| Loans Secured by Real Estate [Member] \| Construction, Land Development and Other Land [Member] \| Pass - RR 1 through RR 6 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	170,118
Term Loans by Origination Year, 2019	146,424
Term Loans by Origination Year, 2018	36,674
Term Loans by Origination Year, 2017	5,413
Term Loans by Origination Year, 2016	3,571
Term Loans by Origination Year, Prior to 2016	5,192
Financing Receivable, Revolving Loans	37,106
Financing Receivable, before Allowance for Credit Loss	404,498
Commercial LHFI [Member] \| Loans Secured by Real Estate [Member] \| Construction, Land Development and Other Land [Member] \| Substandard - RR 8 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	2,417
Term Loans by Origination Year, 2019	74
Term Loans by Origination Year, 2018	495
Term Loans by Origination Year, 2017	47
Term Loans by Origination Year, 2016	680
Term Loans by Origination Year, Prior to 2016	26
Financing Receivable, before Allowance for Credit Loss	3,739
Commercial LHFI [Member] \| Loans Secured by Real Estate [Member] \| Construction, Land Development and Other Land [Member] \| Doubtful - RR 9 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, Prior to 2016	42
Financing Receivable, before Allowance for Credit Loss	42
Commercial LHFI [Member] \| Loans Secured by Real Estate [Member] \| Other Secured by 1-4 Family Residential Properties [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	26,218
Term Loans by Origination Year, 2019	29,291
Term Loans by Origination Year, 2018	23,089
Term Loans by Origination Year, 2017	12,196
Term Loans by Origination Year, 2016	14,212
Term Loans by Origination Year, Prior to 2016	9,355
Financing Receivable, Revolving Loans	7,010
Financing Receivable, before Allowance for Credit Loss	121,371
Commercial LHFI [Member] \| Loans Secured by Real Estate [Member] \| Other Secured by 1-4 Family Residential Properties [Member] \| Pass - RR 1 through RR 6 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	21,491
Term Loans by Origination Year, 2019	28,901
Term Loans by Origination Year, 2018	22,057
Term Loans by Origination Year, 2017	11,956
Term Loans by Origination Year, 2016	14,141
Term Loans by Origination Year, Prior to 2016	8,565
Financing Receivable, Revolving Loans	7,010
Financing Receivable, before Allowance for Credit Loss	114,121
Commercial LHFI [Member] \| Loans Secured by Real Estate [Member] \| Other Secured by 1-4 Family Residential Properties [Member] \| Special Mention - RR 7 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2019	90
Financing Receivable, before Allowance for Credit Loss	90
Commercial LHFI [Member] \| Loans Secured by Real Estate [Member] \| Other Secured by 1-4 Family Residential Properties [Member] \| Substandard - RR 8 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	4,694
Term Loans by Origination Year, 2019	299
Term Loans by Origination Year, 2018	1,032
Term Loans by Origination Year, 2017	240
Term Loans by Origination Year, 2016	71
Term Loans by Origination Year, Prior to 2016	790
Financing Receivable, before Allowance for Credit Loss	7,126
Commercial LHFI [Member] \| Loans Secured by Real Estate [Member] \| Other Secured by 1-4 Family Residential Properties [Member] \| Doubtful - RR 9 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	33
Term Loans by Origination Year, 2019	1
Financing Receivable, before Allowance for Credit Loss	34
Commercial LHFI [Member] \| Loans Secured by Real Estate [Member] \| Other Real Estate Secured [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	68,617
Term Loans by Origination Year, 2019	181,430
Term Loans by Origination Year, 2018	295,694
Term Loans by Origination Year, 2017	160,526
Term Loans by Origination Year, 2016	130,873
Term Loans by Origination Year, Prior to 2016	36,772
Financing Receivable, Revolving Loans	10,314
Financing Receivable, before Allowance for Credit Loss	884,226
Commercial LHFI [Member] \| Loans Secured by Real Estate [Member] \| Other Real Estate Secured [Member] \| Pass - RR 1 through RR 6 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	67,416
Term Loans by Origination Year, 2019	181,243
Term Loans by Origination Year, 2018	295,676
Term Loans by Origination Year, 2017	160,526
Term Loans by Origination Year, 2016	130,810
Term Loans by Origination Year, Prior to 2016	35,183
Financing Receivable, Revolving Loans	10,314
Financing Receivable, before Allowance for Credit Loss	881,168
Commercial LHFI [Member] \| Loans Secured by Real Estate [Member] \| Other Real Estate Secured [Member] \| Special Mention - RR 7 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, Prior to 2016	874
Financing Receivable, before Allowance for Credit Loss	874
Commercial LHFI [Member] \| Loans Secured by Real Estate [Member] \| Other Real Estate Secured [Member] \| Substandard - RR 8 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	1,201
Term Loans by Origination Year, 2019	187
Term Loans by Origination Year, 2018	18
Term Loans by Origination Year, 2016	63
Term Loans by Origination Year, Prior to 2016	715
Financing Receivable, before Allowance for Credit Loss	2,184
Commercial LHFI [Member] \| Loans Secured by Real Estate [Member] \| Secured by Nonfarm, Nonresidential Properties [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	324,216
Term Loans by Origination Year, 2019	536,071
Term Loans by Origination Year, 2018	468,946
Term Loans by Origination Year, 2017	388,181
Term Loans by Origination Year, 2016	341,938
Term Loans by Origination Year, Prior to 2016	442,068
Financing Receivable, Revolving Loans	108,953
Financing Receivable, before Allowance for Credit Loss	2,610,373	2,475,090
Commercial LHFI [Member] \| Loans Secured by Real Estate [Member] \| Secured by Nonfarm, Nonresidential Properties [Member] \| Pass - RR 1 through RR 6 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	315,293
Term Loans by Origination Year, 2019	519,415
Term Loans by Origination Year, 2018	466,036
Term Loans by Origination Year, 2017	384,595
Term Loans by Origination Year, 2016	332,457
Term Loans by Origination Year, Prior to 2016	424,260
Financing Receivable, Revolving Loans	108,032
Financing Receivable, before Allowance for Credit Loss	2,550,088	2,430,761
Commercial LHFI [Member] \| Loans Secured by Real Estate [Member] \| Secured by Nonfarm, Nonresidential Properties [Member] \| Special Mention - RR 7 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2019	5,655
Term Loans by Origination Year, 2018	1,083
Term Loans by Origination Year, 2016	350
Term Loans by Origination Year, Prior to 2016	4,894
Financing Receivable, before Allowance for Credit Loss	11,982
Commercial LHFI [Member] \| Loans Secured by Real Estate [Member] \| Secured by Nonfarm, Nonresidential Properties [Member] \| Substandard - RR 8 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	8,866
Term Loans by Origination Year, 2019	10,821
Term Loans by Origination Year, 2018	1,827
Term Loans by Origination Year, 2017	3,586
Term Loans by Origination Year, 2016	9,131
Term Loans by Origination Year, Prior to 2016	12,583
Financing Receivable, Revolving Loans	921
Financing Receivable, before Allowance for Credit Loss	47,735	44,001
Commercial LHFI [Member] \| Loans Secured by Real Estate [Member] \| Secured by Nonfarm, Nonresidential Properties [Member] \| Doubtful - RR 9 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	57
Term Loans by Origination Year, 2019	180
Term Loans by Origination Year, Prior to 2016	331
Financing Receivable, before Allowance for Credit Loss	568	328
Commercial LHFI [Member] \| Other Loans Secured by Real Estate [Member] \| Other Construction [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	76,743
Term Loans by Origination Year, 2019	448,004
Term Loans by Origination Year, 2018	235,925
Term Loans by Origination Year, 2017	25,957
Term Loans by Origination Year, 2016	1,481
Financing Receivable, Revolving Loans	6,858
Financing Receivable, before Allowance for Credit Loss	794,968
Commercial LHFI [Member] \| Other Loans Secured by Real Estate [Member] \| Other Construction [Member] \| Pass - RR 1 through RR 6 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	63,346
Term Loans by Origination Year, 2019	448,004
Term Loans by Origination Year, 2018	235,925
Term Loans by Origination Year, 2017	25,957
Term Loans by Origination Year, 2016	1,481
Financing Receivable, Revolving Loans	6,858
Financing Receivable, before Allowance for Credit Loss	781,571
Commercial LHFI [Member] \| Other Loans Secured by Real Estate [Member] \| Other Construction [Member] \| Substandard - RR 8 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	13,397
Financing Receivable, before Allowance for Credit Loss	13,397
Consumer LHFI [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	202,155
Term Loans by Origination Year, 2019	346,251
Term Loans by Origination Year, 2018	268,804
Term Loans by Origination Year, 2017	130,650
Term Loans by Origination Year, 2016	138,204
Term Loans by Origination Year, Prior to 2016	423,217
Financing Receivable, Revolving Loans	422,071
Financing Receivable, before Allowance for Credit Loss	1,931,352	9,335,628
Consumer LHFI [Member] \| Commercial and Industrial Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Financing Receivable, before Allowance for Credit Loss		1,477,896
Consumer LHFI [Member] \| State and Other Political Subdivision Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Financing Receivable, before Allowance for Credit Loss		967,944
Consumer LHFI [Member] \| Consumer Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	38,261
Term Loans by Origination Year, 2019	43,061
Term Loans by Origination Year, 2018	21,353
Term Loans by Origination Year, 2017	7,184
Term Loans by Origination Year, 2016	2,072
Term Loans by Origination Year, Prior to 2016	869
Financing Receivable, Revolving Loans	51,760
Financing Receivable, before Allowance for Credit Loss	164,560	175,738
Consumer LHFI [Member] \| Consumer Loans [Member] \| Current [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	38,008
Term Loans by Origination Year, 2019	42,705
Term Loans by Origination Year, 2018	21,144
Term Loans by Origination Year, 2017	7,161
Term Loans by Origination Year, 2016	2,069
Term Loans by Origination Year, Prior to 2016	864
Financing Receivable, Revolving Loans	51,259
Financing Receivable, before Allowance for Credit Loss	163,210
Consumer LHFI [Member] \| Consumer Loans [Member] \| Past Due 30-89 Days [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	219
Term Loans by Origination Year, 2019	330
Term Loans by Origination Year, 2018	129
Term Loans by Origination Year, 2017	3
Term Loans by Origination Year, Prior to 2016	5
Financing Receivable, Revolving Loans	326
Financing Receivable, before Allowance for Credit Loss	1,012
Consumer LHFI [Member] \| Consumer Loans [Member] \| Past Due 90 Days or More [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	28
Term Loans by Origination Year, 2019	4
Term Loans by Origination Year, 2018	11
Term Loans by Origination Year, 2017	1
Financing Receivable, Revolving Loans	174
Financing Receivable, before Allowance for Credit Loss	218
Consumer LHFI [Member] \| Consumer Loans [Member] \| Nonaccrual [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	6
Term Loans by Origination Year, 2019	22
Term Loans by Origination Year, 2018	69
Term Loans by Origination Year, 2017	19
Term Loans by Origination Year, 2016	3
Financing Receivable, Revolving Loans	1
Financing Receivable, before Allowance for Credit Loss	120
Consumer LHFI [Member] \| Loans Secured by Real Estate [Member] \| Construction, Land Development and Other Land [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	15,175
Term Loans by Origination Year, 2019	39,837
Term Loans by Origination Year, 2018	10,710
Term Loans by Origination Year, 2017	2,398
Term Loans by Origination Year, 2016	1,803
Term Loans by Origination Year, Prior to 2016	4,107
Financing Receivable, before Allowance for Credit Loss	74,030
Consumer LHFI [Member] \| Loans Secured by Real Estate [Member] \| Construction, Land Development and Other Land [Member] \| Current [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	15,175
Term Loans by Origination Year, 2019	39,837
Term Loans by Origination Year, 2018	10,387
Term Loans by Origination Year, 2017	2,398
Term Loans by Origination Year, 2016	1,784
Term Loans by Origination Year, Prior to 2016	3,955
Financing Receivable, before Allowance for Credit Loss	73,536
Consumer LHFI [Member] \| Loans Secured by Real Estate [Member] \| Construction, Land Development and Other Land [Member] \| Past Due 30-89 Days [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2018	323
Term Loans by Origination Year, Prior to 2016	45
Financing Receivable, before Allowance for Credit Loss	368
Consumer LHFI [Member] \| Loans Secured by Real Estate [Member] \| Construction, Land Development and Other Land [Member] \| Nonaccrual [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2016	19
Term Loans by Origination Year, Prior to 2016	107
Financing Receivable, before Allowance for Credit Loss	126
Consumer LHFI [Member] \| Loans Secured by Real Estate [Member] \| Other Secured by 1-4 Family Residential Properties [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	11,365
Term Loans by Origination Year, 2019	19,594
Term Loans by Origination Year, 2018	15,120
Term Loans by Origination Year, 2017	4,934
Term Loans by Origination Year, 2016	2,755
Term Loans by Origination Year, Prior to 2016	17,378
Financing Receivable, Revolving Loans	370,311
Financing Receivable, before Allowance for Credit Loss	441,457
Consumer LHFI [Member] \| Loans Secured by Real Estate [Member] \| Other Secured by 1-4 Family Residential Properties [Member] \| Current [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	11,365
Term Loans by Origination Year, 2019	19,349
Term Loans by Origination Year, 2018	14,814
Term Loans by Origination Year, 2017	4,464
Term Loans by Origination Year, 2016	2,697
Term Loans by Origination Year, Prior to 2016	16,646
Financing Receivable, Revolving Loans	367,313
Financing Receivable, before Allowance for Credit Loss	436,648
Consumer LHFI [Member] \| Loans Secured by Real Estate [Member] \| Other Secured by 1-4 Family Residential Properties [Member] \| Past Due 30-89 Days [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2019	210
Term Loans by Origination Year, 2018	162
Term Loans by Origination Year, 2016	58
Term Loans by Origination Year, Prior to 2016	155
Financing Receivable, Revolving Loans	914
Financing Receivable, before Allowance for Credit Loss	1,499
Consumer LHFI [Member] \| Loans Secured by Real Estate [Member] \| Other Secured by 1-4 Family Residential Properties [Member] \| Past Due 90 Days or More [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, Prior to 2016	13
Financing Receivable, Revolving Loans	38
Financing Receivable, before Allowance for Credit Loss	51
Consumer LHFI [Member] \| Loans Secured by Real Estate [Member] \| Other Secured by 1-4 Family Residential Properties [Member] \| Nonaccrual [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2019	35
Term Loans by Origination Year, 2018	144
Term Loans by Origination Year, 2017	470
Term Loans by Origination Year, Prior to 2016	564
Financing Receivable, Revolving Loans	2,046
Financing Receivable, before Allowance for Credit Loss	3,259
Consumer LHFI [Member] \| Loans Secured by Real Estate [Member] \| Other Real Estate Secured [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	91
Term Loans by Origination Year, 2018	44
Term Loans by Origination Year, 2017	46
Term Loans by Origination Year, 2016	106
Term Loans by Origination Year, Prior to 2016	302
Financing Receivable, before Allowance for Credit Loss	589
Consumer LHFI [Member] \| Loans Secured by Real Estate [Member] \| Other Real Estate Secured [Member] \| Current [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	91
Term Loans by Origination Year, 2018	44
Term Loans by Origination Year, 2017	46
Term Loans by Origination Year, 2016	106
Term Loans by Origination Year, Prior to 2016	302
Financing Receivable, before Allowance for Credit Loss	589
Consumer LHFI [Member] \| Loans Secured by Real Estate [Member] \| Secured by Nonfarm, Nonresidential Properties [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2017	5
Term Loans by Origination Year, Prior to 2016	14
Financing Receivable, before Allowance for Credit Loss	19	$ 2,475,245
Consumer LHFI [Member] \| Loans Secured by Real Estate [Member] \| Secured by Nonfarm, Nonresidential Properties [Member] \| Current [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2017	5
Term Loans by Origination Year, Prior to 2016	14
Financing Receivable, before Allowance for Credit Loss	19
Consumer LHFI [Member] \| Other Loans Secured by Real Estate [Member] \| Secured by 1-4 Family Residential Properties [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	137,263
Term Loans by Origination Year, 2019	243,759
Term Loans by Origination Year, 2018	221,577
Term Loans by Origination Year, 2017	116,083
Term Loans by Origination Year, 2016	131,468
Term Loans by Origination Year, Prior to 2016	400,547
Financing Receivable, before Allowance for Credit Loss	1,250,697
Consumer LHFI [Member] \| Other Loans Secured by Real Estate [Member] \| Secured by 1-4 Family Residential Properties [Member] \| Current [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	137,146
Term Loans by Origination Year, 2019	242,961
Term Loans by Origination Year, 2018	218,993
Term Loans by Origination Year, 2017	115,354
Term Loans by Origination Year, 2016	130,831
Term Loans by Origination Year, Prior to 2016	390,425
Financing Receivable, before Allowance for Credit Loss	1,235,710
Consumer LHFI [Member] \| Other Loans Secured by Real Estate [Member] \| Secured by 1-4 Family Residential Properties [Member] \| Past Due 30-89 Days [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	73
Term Loans by Origination Year, 2019	85
Term Loans by Origination Year, 2018	77
Term Loans by Origination Year, 2017	123
Term Loans by Origination Year, 2016	79
Term Loans by Origination Year, Prior to 2016	1,497
Financing Receivable, before Allowance for Credit Loss	1,934
Consumer LHFI [Member] \| Other Loans Secured by Real Estate [Member] \| Secured by 1-4 Family Residential Properties [Member] \| Past Due 90 Days or More [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2017	139
Term Loans by Origination Year, Prior to 2016	390
Financing Receivable, before Allowance for Credit Loss	529

Loans Held for Investment (LHFI) and Allowance for Loan Losses, LHFI - Summary of Amortized Cost Basis of Loans by Credit Quality Indicator (Details) - USD ($)
$ in Thousands