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	Mar. 31, 2020	Dec. 31, 2019
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	$ 590,609
Term Loans by Origination Year, 2019	2,262,786
Term Loans by Origination Year, 2018	1,660,237
Term Loans by Origination Year, 2017	1,039,291
Term Loans by Origination Year, 2016	982,810
Term Loans by Origination Year, Prior to 2016	1,564,386
Financing Receivable, Revolving Loans	1,467,801
Financing Receivable, before Allowance for Credit Loss	9,567,920
Commercial LHFI [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	513,950
Term Loans by Origination Year, 2019	1,884,719
Term Loans by Origination Year, 2018	1,344,993
Term Loans by Origination Year, 2017	891,174
Term Loans by Origination Year, 2016	833,904
Term Loans by Origination Year, Prior to 2016	1,095,472
Financing Receivable, Revolving Loans	1,028,150
Financing Receivable, before Allowance for Credit Loss	7,592,362	$ 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 [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	183,597
Term Loans by Origination Year, 2019	297,177
Term Loans by Origination Year, 2018	165,989
Term Loans by Origination Year, 2017	116,222
Term Loans by Origination Year, 2016	86,985
Term Loans by Origination Year, Prior to 2016	62,569
Financing Receivable, Revolving Loans	564,238
Financing Receivable, before Allowance for Credit Loss	1,476,777	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	175,477
Term Loans by Origination Year, 2019	294,301
Term Loans by Origination Year, 2018	146,947
Term Loans by Origination Year, 2017	115,358
Term Loans by Origination Year, 2016	85,992
Term Loans by Origination Year, Prior to 2016	59,924
Financing Receivable, Revolving Loans	540,814
Financing Receivable, before Allowance for Credit Loss	1,418,813	1,407,837
Commercial LHFI [Member] | Commercial and Industrial Loans [Member] | Special Mention - RR 7 [Member]
Financing Receivable Recorded Investment [Line Items]
Financing Receivable, before Allowance for Credit Loss		909
Commercial LHFI [Member] | Commercial and Industrial Loans [Member] | Substandard - RR [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	8,103
Term Loans by Origination Year, 2019	2,336
Term Loans by Origination Year, 2018	19,042
Term Loans by Origination Year, 2017	864
Term Loans by Origination Year, 2016	724
Term Loans by Origination Year, Prior to 2016	2,641
Financing Receivable, Revolving Loans	23,416
Financing Receivable, before Allowance for Credit Loss	57,126	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	17
Term Loans by Origination Year, 2019	540
Term Loans by Origination Year, 2016	269
Term Loans by Origination Year, Prior to 2016	4
Financing Receivable, Revolving Loans	8
Financing Receivable, before Allowance for Credit Loss	838	888
Commercial LHFI [Member] | State and Other Political Subdivision Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	30,645
Term Loans by Origination Year, 2019	134,410
Term Loans by Origination Year, 2018	76,100
Term Loans by Origination Year, 2017	124,472
Term Loans by Origination Year, 2016	147,560
Term Loans by Origination Year, Prior to 2016	424,645
Financing Receivable, Revolving Loans	805
Financing Receivable, before Allowance for Credit Loss	938,637	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	30,645
Term Loans by Origination Year, 2019	134,410
Term Loans by Origination Year, 2018	76,100
Term Loans by Origination Year, 2017	124,088
Term Loans by Origination Year, 2016	147,560
Term Loans by Origination Year, Prior to 2016	415,156
Financing Receivable, Revolving Loans	805
Financing Receivable, before Allowance for Credit Loss	928,764	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	4,650
Financing Receivable, before Allowance for Credit Loss	4,650	4,650
Commercial LHFI [Member] | State and Other Political Subdivision Loans [Member] | Substandard - RR [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2017	384
Term Loans by Origination Year, Prior to 2016	4,839
Financing Receivable, before Allowance for Credit Loss	5,223	5,346
Commercial LHFI [Member] | Other Commercial Loans [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	37,485
Term Loans by Origination Year, 2019	92,852
Term Loans by Origination Year, 2018	36,513
Term Loans by Origination Year, 2017	15,836
Term Loans by Origination Year, 2016	60,081
Term Loans by Origination Year, Prior to 2016	55,370
Financing Receivable, Revolving Loans	278,242
Financing Receivable, before Allowance for Credit Loss	576,379
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	37,485
Term Loans by Origination Year, 2019	90,436
Term Loans by Origination Year, 2018	35,815
Term Loans by Origination Year, 2017	15,742
Term Loans by Origination Year, 2016	58,816
Term Loans by Origination Year, Prior to 2016	55,347
Financing Receivable, Revolving Loans	267,500
Financing Receivable, before Allowance for Credit Loss	561,141
Commercial LHFI [Member] | Other Commercial Loans [Member] | Special Mention - RR 7 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2019	2,028
Financing Receivable, Revolving Loans	2,995
Financing Receivable, before Allowance for Credit Loss	5,023
Commercial LHFI [Member] | Other Commercial Loans [Member] | Substandard - RR [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2019	299
Term Loans by Origination Year, 2018	698
Term Loans by Origination Year, 2017	94
Term Loans by Origination Year, 2016	1,265
Financing Receivable, Revolving Loans	7,747
Financing Receivable, before Allowance for Credit Loss	10,103
Commercial LHFI [Member] | Other Commercial Loans [Member] | Doubtful - RR 9 [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2019	89
Term Loans by Origination Year, Prior to 2016	23
Financing Receivable, before Allowance for Credit Loss	112
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	78,618
Term Loans by Origination Year, 2019	224,530
Term Loans by Origination Year, 2018	54,655
Term Loans by Origination Year, 2017	7,358
Term Loans by Origination Year, 2016	4,908
Term Loans by Origination Year, Prior to 2016	6,858
Financing Receivable, Revolving Loans	36,843
Financing Receivable, before Allowance for Credit Loss	413,770
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	77,319
Term Loans by Origination Year, 2019	223,340
Term Loans by Origination Year, 2018	54,232
Term Loans by Origination Year, 2017	7,319
Term Loans by Origination Year, 2016	4,228
Term Loans by Origination Year, Prior to 2016	6,771
Financing Receivable, Revolving Loans	36,843
Financing Receivable, before Allowance for Credit Loss	410,052
Commercial LHFI [Member] | Loans Secured by Real Estate [Member] | Construction, Land Development and Other Land [Member] | Substandard - RR [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	1,299
Term Loans by Origination Year, 2019	1,190
Term Loans by Origination Year, 2018	423
Term Loans by Origination Year, 2017	39
Term Loans by Origination Year, 2016	680
Term Loans by Origination Year, Prior to 2016	45
Financing Receivable, before Allowance for Credit Loss	3,676
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	8,030
Term Loans by Origination Year, 2019	36,952
Term Loans by Origination Year, 2018	26,311
Term Loans by Origination Year, 2017	13,989
Term Loans by Origination Year, 2016	14,990
Term Loans by Origination Year, Prior to 2016	11,488
Financing Receivable, Revolving Loans	11,626
Financing Receivable, before Allowance for Credit Loss	123,386
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	7,746
Term Loans by Origination Year, 2019	32,807
Term Loans by Origination Year, 2018	25,192
Term Loans by Origination Year, 2017	13,745
Term Loans by Origination Year, 2016	14,504
Term Loans by Origination Year, Prior to 2016	10,639
Financing Receivable, Revolving Loans	11,512
Financing Receivable, before Allowance for Credit Loss	116,145
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	92
Financing Receivable, before Allowance for Credit Loss	92
Commercial LHFI [Member] | Loans Secured by Real Estate [Member] | Other Secured by 1-4 Family Residential Properties [Member] | Substandard - RR [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	284
Term Loans by Origination Year, 2019	4,016
Term Loans by Origination Year, 2018	1,119
Term Loans by Origination Year, 2017	244
Term Loans by Origination Year, 2016	486
Term Loans by Origination Year, Prior to 2016	849
Financing Receivable, Revolving Loans	114
Financing Receivable, before Allowance for Credit Loss	7,112
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, 2019	37
Financing Receivable, before Allowance for Credit Loss	37
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	18,032
Term Loans by Origination Year, 2019	180,838
Term Loans by Origination Year, 2018	270,470
Term Loans by Origination Year, 2017	177,386
Term Loans by Origination Year, 2016	137,018
Term Loans by Origination Year, Prior to 2016	41,584
Financing Receivable, Revolving Loans	12,561
Financing Receivable, before Allowance for Credit Loss	837,889
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	18,032
Term Loans by Origination Year, 2019	180,641
Term Loans by Origination Year, 2018	269,166
Term Loans by Origination Year, 2017	177,386
Term Loans by Origination Year, 2016	136,620
Term Loans by Origination Year, Prior to 2016	40,741
Financing Receivable, Revolving Loans	12,561
Financing Receivable, before Allowance for Credit Loss	835,147
Commercial LHFI [Member] | Loans Secured by Real Estate [Member] | Other Real Estate Secured [Member] | Substandard - RR [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2019	197
Term Loans by Origination Year, 2018	1,304
Term Loans by Origination Year, 2016	398
Term Loans by Origination Year, Prior to 2016	843
Financing Receivable, before Allowance for Credit Loss	2,742
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	137,174
Term Loans by Origination Year, 2019	558,243
Term Loans by Origination Year, 2018	496,915
Term Loans by Origination Year, 2017	411,712
Term Loans by Origination Year, 2016	359,208
Term Loans by Origination Year, Prior to 2016	492,958
Financing Receivable, Revolving Loans	119,190
Financing Receivable, before Allowance for Credit Loss	2,575,400	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	132,966
Term Loans by Origination Year, 2019	542,615
Term Loans by Origination Year, 2018	495,056
Term Loans by Origination Year, 2017	407,125
Term Loans by Origination Year, 2016	350,006
Term Loans by Origination Year, Prior to 2016	474,906
Financing Receivable, Revolving Loans	118,137
Financing Receivable, before Allowance for Credit Loss	2,520,811	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	740
Term Loans by Origination Year, Prior to 2016	4,826
Financing Receivable, before Allowance for Credit Loss	5,566
Commercial LHFI [Member] | Loans Secured by Real Estate [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Substandard - RR [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	4,148
Term Loans by Origination Year, 2019	14,888
Term Loans by Origination Year, 2018	1,859
Term Loans by Origination Year, 2017	4,587
Term Loans by Origination Year, 2016	9,202
Term Loans by Origination Year, Prior to 2016	12,885
Financing Receivable, Revolving Loans	1,053
Financing Receivable, before Allowance for Credit Loss	48,622	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	60
Term Loans by Origination Year, Prior to 2016	341
Financing Receivable, before Allowance for Credit Loss	401	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	20,369
Term Loans by Origination Year, 2019	359,717
Term Loans by Origination Year, 2018	218,040
Term Loans by Origination Year, 2017	24,199
Term Loans by Origination Year, 2016	23,154
Financing Receivable, Revolving Loans	4,645
Financing Receivable, before Allowance for Credit Loss	650,124
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	20,369
Term Loans by Origination Year, 2019	359,717
Term Loans by Origination Year, 2018	203,819
Term Loans by Origination Year, 2017	24,199
Term Loans by Origination Year, 2016	23,154
Financing Receivable, Revolving Loans	4,645
Financing Receivable, before Allowance for Credit Loss	635,903
Commercial LHFI [Member] | Other Loans Secured by Real Estate [Member] | Other Construction [Member] | Substandard - RR [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2018	14,221
Financing Receivable, before Allowance for Credit Loss	14,221
Consumer LHFI [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	76,659
Term Loans by Origination Year, 2019	378,067
Term Loans by Origination Year, 2018	315,244
Term Loans by Origination Year, 2017	148,117
Term Loans by Origination Year, 2016	148,906
Term Loans by Origination Year, Prior to 2016	468,914
Financing Receivable, Revolving Loans	439,651
Financing Receivable, before Allowance for Credit Loss	1,975,558	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	24,236
Term Loans by Origination Year, 2019	54,251
Term Loans by Origination Year, 2018	26,227
Term Loans by Origination Year, 2017	10,264
Term Loans by Origination Year, 2016	2,786
Term Loans by Origination Year, Prior to 2016	1,407
Financing Receivable, Revolving Loans	54,507
Financing Receivable, before Allowance for Credit Loss	173,678	175,738
Consumer LHFI [Member] | Consumer Loans [Member] | Current [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	23,790
Term Loans by Origination Year, 2019	53,753
Term Loans by Origination Year, 2018	25,875
Term Loans by Origination Year, 2017	10,148
Term Loans by Origination Year, 2016	2,751
Term Loans by Origination Year, Prior to 2016	1,390
Financing Receivable, Revolving Loans	53,694
Financing Receivable, before Allowance for Credit Loss	171,401
Consumer LHFI [Member] | Consumer Loans [Member] | Past Due 30-89 Days [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2020	425
Term Loans by Origination Year, 2019	469
Term Loans by Origination Year, 2018	313
Term Loans by Origination Year, 2017	89
Term Loans by Origination Year, 2016	31
Term Loans by Origination Year, Prior to 2016	9
Financing Receivable, Revolving Loans	561
Financing Receivable, before Allowance for Credit Loss	1,897
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	21
Term Loans by Origination Year, 2019	12
Term Loans by Origination Year, 2018	11
Financing Receivable, Revolving Loans	252
Financing Receivable, before Allowance for Credit Loss	296
Consumer LHFI [Member] | Consumer Loans [Member] | Nonaccrual [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2019	17
Term Loans by Origination Year, 2018	28
Term Loans by Origination Year, 2017	27
Term Loans by Origination Year, 2016	4
Term Loans by Origination Year, Prior to 2016	8
Financing Receivable, before Allowance for Credit Loss	84
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	4,470
Term Loans by Origination Year, 2019	44,148
Term Loans by Origination Year, 2018	14,563
Term Loans by Origination Year, 2017	2,583
Term Loans by Origination Year, 2016	2,021
Term Loans by Origination Year, Prior to 2016	4,710
Financing Receivable, before Allowance for Credit Loss	72,495
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	4,470
Term Loans by Origination Year, 2019	44,148
Term Loans by Origination Year, 2018	14,499
Term Loans by Origination Year, 2017	2,531
Term Loans by Origination Year, 2016	1,992
Term Loans by Origination Year, Prior to 2016	4,557
Financing Receivable, before Allowance for Credit Loss	72,197
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	64
Term Loans by Origination Year, 2017	52
Term Loans by Origination Year, 2016	29
Term Loans by Origination Year, Prior to 2016	43
Financing Receivable, before Allowance for Credit Loss	188
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, Prior to 2016	110
Financing Receivable, before Allowance for Credit Loss	110
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	5,719
Term Loans by Origination Year, 2019	24,767
Term Loans by Origination Year, 2018	17,405
Term Loans by Origination Year, 2017	5,703
Term Loans by Origination Year, 2016	2,891
Term Loans by Origination Year, Prior to 2016	19,966
Financing Receivable, Revolving Loans	385,144
Financing Receivable, before Allowance for Credit Loss	461,595
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	5,636
Term Loans by Origination Year, 2019	24,558
Term Loans by Origination Year, 2018	17,083
Term Loans by Origination Year, 2017	5,225
Term Loans by Origination Year, 2016	2,833
Term Loans by Origination Year, Prior to 2016	17,902
Financing Receivable, Revolving Loans	380,934
Financing Receivable, before Allowance for Credit Loss	454,171
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	166
Term Loans by Origination Year, 2018	111
Term Loans by Origination Year, 2017	30
Term Loans by Origination Year, 2016	58
Term Loans by Origination Year, Prior to 2016	1,384
Financing Receivable, Revolving Loans	1,870
Financing Receivable, before Allowance for Credit Loss	3,619
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, 2019	5
Term Loans by Origination Year, Prior to 2016	2
Financing Receivable, Revolving Loans	34
Financing Receivable, before Allowance for Credit Loss	41
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, 2020	83
Term Loans by Origination Year, 2019	38
Term Loans by Origination Year, 2018	211
Term Loans by Origination Year, 2017	448
Term Loans by Origination Year, Prior to 2016	678
Financing Receivable, Revolving Loans	2,306
Financing Receivable, before Allowance for Credit Loss	3,764
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	60
Term Loans by Origination Year, 2018	47
Term Loans by Origination Year, 2017	47
Term Loans by Origination Year, 2016	111
Term Loans by Origination Year, Prior to 2016	419
Financing Receivable, before Allowance for Credit Loss	684
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	60
Term Loans by Origination Year, 2018	47
Term Loans by Origination Year, 2017	47
Term Loans by Origination Year, 2016	111
Term Loans by Origination Year, Prior to 2016	419
Financing Receivable, before Allowance for Credit Loss	684
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	6
Term Loans by Origination Year, Prior to 2016	16
Financing Receivable, before Allowance for Credit Loss	22	$ 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, Prior to 2016	16
Financing Receivable, before Allowance for Credit Loss	16
Consumer LHFI [Member] | Loans Secured by Real Estate [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Past Due 30-89 Days [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2017	6
Financing Receivable, before Allowance for Credit Loss	6
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	42,174
Term Loans by Origination Year, 2019	254,901
Term Loans by Origination Year, 2018	257,002
Term Loans by Origination Year, 2017	129,514
Term Loans by Origination Year, 2016	141,097
Term Loans by Origination Year, Prior to 2016	442,396
Financing Receivable, before Allowance for Credit Loss	1,267,084
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	42,174
Term Loans by Origination Year, 2019	253,904
Term Loans by Origination Year, 2018	251,953
Term Loans by Origination Year, 2017	128,603
Term Loans by Origination Year, 2016	140,848
Term Loans by Origination Year, Prior to 2016	431,984
Financing Receivable, before Allowance for Credit Loss	1,249,466
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, 2019	271
Term Loans by Origination Year, 2018	2,649
Term Loans by Origination Year, 2017	123
Term Loans by Origination Year, Prior to 2016	1,803
Financing Receivable, before Allowance for Credit Loss	4,846
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, 2019	96
Term Loans by Origination Year, 2018	148
Term Loans by Origination Year, Prior to 2016	61
Financing Receivable, before Allowance for Credit Loss	305
Consumer LHFI [Member] | Other Loans Secured by Real Estate [Member] | Secured by 1-4 Family Residential Properties [Member] | Nonaccrual [Member]
Financing Receivable Recorded Investment [Line Items]
Term Loans by Origination Year, 2019	630
Term Loans by Origination Year, 2018	2,252
Term Loans by Origination Year, 2017	788
Term Loans by Origination Year, 2016	249
Term Loans by Origination Year, Prior to 2016	8,548
Financing Receivable, before Allowance for Credit Loss	$ 12,467