Allowance for Credit Losses - Activity in Allowance for Credit Losses (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	$ 81,127	$ 91,250	$ 92,733	$ 35,154
Initial Allowance on PCD Loans Acquired During the Period	3,046	5,763	3,046	6,279
Provision for Credit Losses	5,091	(1,245)	(5,479)	35,879
Charge- Offs	(2,052)	(2,175)	(4,777)	(6,316)
Recoveries	620	439	2,320	1,856
TDR Allowance Adjustments	(9)	(19)	(20)	(65)
Ending Balance	87,823	94,013	87,823	94,013
Construction and land development
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	4,053	7,161	4,920	1,842
Initial Allowance on PCD Loans Acquired During the Period	0	39	0	87
Provision for Credit Losses	(1,459)	475	(2,438)	4,202
Charge- Offs	0	0	0	0
Recoveries	10	26	124	92
TDR Allowance Adjustments	(1)	0	(3)	(1)
Ending Balance	2,603	7,701	2,603	7,701
Commercial real estate - owner-occupied
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	8,676	5,562	9,868	5,361
Initial Allowance on PCD Loans Acquired During the Period	0	954	0	1,161
Provision for Credit Losses	(24)	689	(1,216)	655
Charge- Offs	0	0	0	(45)
Recoveries	0	26	0	44
TDR Allowance Adjustments	0	(12)	0	(37)
Ending Balance	8,652	7,219	8,652	7,219
Commercial real estate - non owner-occupied
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	34,807	38,992	38,266	7,863
Initial Allowance on PCD Loans Acquired During the Period	1,327	2,096	1,327	2,236
Provision for Credit Losses	5,278	(7,050)	1,817	14,578
Charge- Offs	(1,327)	(25)	(1,327)	(37)
Recoveries	0	5	2	37
TDR Allowance Adjustments	0	0	0	0
Ending Balance	40,085	34,018	40,085	34,018
Residential real estate
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	12,543	20,453	17,500	7,667
Initial Allowance on PCD Loans Acquired During the Period	0	27	0	124
Provision for Credit Losses	1,456	(3,196)	(4,323)	3,638
Charge- Offs	(27)	(19)	(48)	(150)
Recoveries	158	65	1,008	283
TDR Allowance Adjustments	(3)	(5)	(10)	(24)
Ending Balance	14,127	17,325	14,127	17,325
Commercial and financial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	18,016	15,514	18,690	9,716
Initial Allowance on PCD Loans Acquired During the Period	1,719	2,632	1,719	2,643
Provision for Credit Losses	(2)	8,081	1,172	12,144
Charge- Offs	(535)	(1,776)	(2,855)	(4,642)
Recoveries	326	203	798	1,116
TDR Allowance Adjustments	0	0	0	0
Ending Balance	19,524	24,654	19,524	24,654
Consumer
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	3,032	3,568	3,489	2,705
Initial Allowance on PCD Loans Acquired During the Period	0	15	0	28
Provision for Credit Losses	(158)	(244)	(491)	662
Charge- Offs	(163)	(355)	(547)	(1,442)
Recoveries	126	114	388	284
TDR Allowance Adjustments	(5)	(2)	(7)	(3)
Ending Balance	2,832	3,096	2,832	3,096
Paycheck Protection Program
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	0	0	0	0
Initial Allowance on PCD Loans Acquired During the Period	0	0		0
Provision for Credit Losses	0	0	0	0
Charge- Offs	0	0	0	0
Recoveries	0	0	0	0
TDR Allowance Adjustments	0	0	0	0
Ending Balance	$ 0	$ 0	$ 0	0
Impact of Adoption of ASC 326
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance				21,226
Impact of Adoption of ASC 326 | Construction and land development
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance				1,479
Impact of Adoption of ASC 326 | Commercial real estate - owner-occupied
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance				80
Impact of Adoption of ASC 326 | Commercial real estate - non owner-occupied
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance				9,341
Impact of Adoption of ASC 326 | Residential real estate
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance				5,787
Impact of Adoption of ASC 326 | Commercial and financial
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance				3,677
Impact of Adoption of ASC 326 | Consumer
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance				862
Impact of Adoption of ASC 326 | Paycheck Protection Program
Financing Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance				$ 0