Loans and Allowance for Credit Losses - Summary of Analysis Performed Risk category Loans (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	$ 2,465,365
2019	291,855
2018	240,124
2017	181,503
2016	72,651
Prior	116,021
Revolving Loans	1,466,782
Revolving Loans Converted To Term Loans	18,610
Total	4,852,911	$ 4,194,512
Purchased Credit Impaired Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total		12,675
Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	2,420,288
2019	282,712
2018	233,522
2017	179,183
2016	70,547
Prior	112,614
Revolving Loans	1,453,456
Revolving Loans Converted To Term Loans	18,610
Total	4,770,932	4,115,695
Classified
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	45,077
2019	9,143
2018	6,602
2017	2,320
2016	2,104
Prior	3,407
Revolving Loans	13,326
Revolving Loans Converted To Term Loans	0
Total	81,979	66,142
Commercial real estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	388,911
2019	85,895
2018	96,000
2017	92,748
2016	36,428
Prior	54,517
Revolving Loans	7,124
Revolving Loans Converted To Term Loans	908
Total	762,531	1,046,961
Commercial real estate | Purchased Credit Impaired Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total		9,067
Commercial real estate | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	374,993
2019	85,458
2018	95,818
2017	92,112
2016	35,576
Prior	53,189
Revolving Loans	7,124
Revolving Loans Converted To Term Loans	908
Total	745,178	1,030,358
Commercial real estate | Classified
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	13,918
2019	437
2018	182
2017	636
2016	852
Prior	1,328
Revolving Loans	0
Revolving Loans Converted To Term Loans	0
Total	17,353	7,536
Construction, land development, land
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	142,845
2019	30,492
2018	55,887
2017	12,362
2016	268
Prior	2,145
Revolving Loans	13
Revolving Loans Converted To Term Loans	500
Total	244,512	160,569
Construction, land development, land | Purchased Credit Impaired Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total		2,446
Construction, land development, land | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	141,940
2019	29,654
2018	55,887
2017	12,362
2016	268
Prior	1,776
Revolving Loans	13
Revolving Loans Converted To Term Loans	500
Total	242,400	155,985
Construction, land development, land | Classified
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	905
2019	838
2018	0
2017	0
2016	0
Prior	369
Revolving Loans	0
Revolving Loans Converted To Term Loans	0
Total	2,112	2,138
1-4 family residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	36,529
2019	12,690
2018	15,188
2017	13,316
2016	12,132
Prior	30,834
Revolving Loans	38,776
Revolving Loans Converted To Term Loans	5,320
Total	164,785	179,425
1-4 family residential | Purchased Credit Impaired Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total		508
1-4 family residential | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	35,959
2019	12,614
2018	15,172
2017	13,316
2016	11,773
Prior	30,076
Revolving Loans	38,669
Revolving Loans Converted To Term Loans	5,320
Total	162,899	177,177
1-4 family residential | Classified
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	570
2019	76
2018	16
2017	0
2016	359
Prior	758
Revolving Loans	107
Revolving Loans Converted To Term Loans	0
Total	1,886	1,740
Farmland
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	21,077
2019	17,517
2018	18,130
2017	15,313
2016	13,829
Prior	21,710
Revolving Loans	2,904
Revolving Loans Converted To Term Loans	486
Total	110,966	154,975
Farmland | Purchased Credit Impaired Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total		104
Farmland | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	19,870
2019	17,100
2018	16,458
2017	15,168
2016	13,829
Prior	21,150
Revolving Loans	2,130
Revolving Loans Converted To Term Loans	486
Total	106,191	144,777
Farmland | Classified
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	1,207
2019	417
2018	1,672
2017	145
2016	0
Prior	560
Revolving Loans	774
Revolving Loans Converted To Term Loans	0
Total	4,775	10,094
Commercial
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	855,846
2019	142,626
2018	53,298
2017	42,976
2016	6,744
Prior	5,896
Revolving Loans	418,121
Revolving Loans Converted To Term Loans	11,396
Total	1,536,903	1,342,683
Commercial | Purchased Credit Impaired Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total		550
Commercial | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	848,660
2019	135,269
2018	48,573
2017	41,531
2016	6,013
Prior	5,548
Revolving Loans	405,676
Revolving Loans Converted To Term Loans	11,396
Total	1,502,666	1,313,042
Commercial | Classified
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	7,186
2019	7,357
2018	4,725
2017	1,445
2016	731
Prior	348
Revolving Loans	12,445
Revolving Loans Converted To Term Loans	0
Total	34,237	29,091
Factored receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	1,016,337
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans	0
Revolving Loans Converted To Term Loans	0
Total	1,016,337	619,986
Factored receivables | Purchased Credit Impaired Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total		0
Factored receivables | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	995,046
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans	0
Revolving Loans Converted To Term Loans	0
Total	995,046	604,774
Factored receivables | Classified
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	21,291
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans	0
Revolving Loans Converted To Term Loans	0
Total	21,291	15,212
Consumer
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	3,820
2019	2,635
2018	1,621
2017	4,788
2016	3,250
Prior	919
Revolving Loans	73
Revolving Loans Converted To Term Loans	0
Total	17,106	21,925
Consumer | Purchased Credit Impaired Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total		0
Consumer | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	3,820
2019	2,617
2018	1,614
2017	4,694
2016	3,088
Prior	875
Revolving Loans	73
Revolving Loans Converted To Term Loans	0
Total	16,781	21,594
Consumer | Classified
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2019	18
2018	7
2017	94
2016	162
Prior	44
Revolving Loans	0
Revolving Loans Converted To Term Loans	0
Total	325	331
Mortgage warehouse
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans	999,771
Revolving Loans Converted To Term Loans	0
Total	999,771	667,988
Mortgage warehouse | Purchased Credit Impaired Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Total		0
Mortgage warehouse | Pass
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans	999,771
Revolving Loans Converted To Term Loans	0
Total	999,771	667,988
Mortgage warehouse | Classified
Accounts, Notes, Loans and Financing Receivable [Line Items]
2020	0
2019	0
2018	0
2017	0
2016	0
Prior	0
Revolving Loans	0
Revolving Loans Converted To Term Loans	0
Total	$ 0	$ 0