Loans Held for Investment (LHFI) and Allowance for Loan Losses, LHFI - Summary of Balance in Allowance for Loan Losses (Details) - USD ($) $ in Thousands	Sep. 30, 2022	Jun. 30, 2022	Dec. 31, 2021	Sep. 30, 2021	Jun. 30, 2021	Dec. 31, 2020
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Total	$ 115,050	$ 103,140	$ 99,457	$ 104,073	$ 104,032	$ 117,306
Allowance for Credit Losses, ACL [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually Evaluated for Credit Loss	19,448		7,625
Collectively Evaluated for Credit Loss	95,602		91,832
Total	115,050	103,140	99,457	104,073	104,032	117,306
Allowance for Loan Losses, LHFI [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually Evaluated for Credit Loss	47,413		44,361
Collectively Evaluated for Credit Loss	11,538,651		10,203,468
Total	11,586,064		10,247,829
Commercial and Industrial Loans [Member] | Allowance for Credit Losses, ACL [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually Evaluated for Credit Loss	10,622		5,750
Collectively Evaluated for Credit Loss	13,482		13,189
Total	24,104	14,103	18,939	19,373	13,973	14,851
Commercial and Industrial Loans [Member] | Allowance for Loan Losses, LHFI [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually Evaluated for Credit Loss	25,281		18,444
Collectively Evaluated for Credit Loss	1,664,251		1,395,835
Total	1,689,532		1,414,279
Consumer Loans [Member] | Allowance for Credit Losses, ACL [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Collectively Evaluated for Credit Loss	5,028		4,774
Total	5,028	5,139	4,774	4,862	4,876	5,838
Consumer Loans [Member] | Allowance for Loan Losses, LHFI [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Collectively Evaluated for Credit Loss	166,027		162,555
Total	166,027		162,555
State and Other Political Subdivision Loans [Member] | Allowance for Credit Losses, ACL [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually Evaluated for Credit Loss	719		1,394
Collectively Evaluated for Credit Loss	875		1,314
Total	1,594	1,917	2,708	2,964	3,233	3,190
State and Other Political Subdivision Loans [Member] | Allowance for Loan Losses, LHFI [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually Evaluated for Credit Loss	2,988		3,664
Collectively Evaluated for Credit Loss	1,185,715		1,142,587
Total	1,188,703		1,146,251
Other Commercial Loans [Member] | Allowance for Credit Losses, ACL [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually Evaluated for Credit Loss	36		203
Collectively Evaluated for Credit Loss	4,662		5,145
Total	4,698	4,963	5,348	5,243	7,274	7,439
Other Commercial Loans [Member] | Allowance for Loan Losses, LHFI [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually Evaluated for Credit Loss	36		4,608
Collectively Evaluated for Credit Loss	497,194		530,235
Total	497,230		534,843
Loans Secured by Real Estate [Member] | Construction, Land Development and Other Land [Member] | Allowance for Credit Losses, ACL [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually Evaluated for Credit Loss	451		278
Collectively Evaluated for Credit Loss	9,800		5,801
Total	10,251	7,301	6,079	5,133	5,110	6,854
Loans Secured by Real Estate [Member] | Construction, Land Development and Other Land [Member] | Allowance for Loan Losses, LHFI [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually Evaluated for Credit Loss	4,273		5,198
Collectively Evaluated for Credit Loss	689,468		591,770
Total	693,741		596,968
Loans Secured by Real Estate [Member] | Other Secured by 1-4 Family Residential Properties [Member] | Allowance for Credit Losses, ACL [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Collectively Evaluated for Credit Loss	10,739		10,310
Total	10,739	10,038	10,310	10,223	10,399	9,928
Loans Secured by Real Estate [Member] | Other Secured by 1-4 Family Residential Properties [Member] | Allowance for Loan Losses, LHFI [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually Evaluated for Credit Loss	489
Collectively Evaluated for Credit Loss	566,496		517,683
Total	566,985		517,683
Loans Secured by Real Estate [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Allowance for Credit Losses, ACL [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Collectively Evaluated for Credit Loss	25,924		37,912
Total	25,924	29,735	37,912	43,306	44,416	48,523
Loans Secured by Real Estate [Member] | Secured by Nonfarm, Nonresidential Properties [Member] | Allowance for Loan Losses, LHFI [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually Evaluated for Credit Loss	5,493		11,072
Collectively Evaluated for Credit Loss	3,201,453		2,966,012
Total	3,206,946		2,977,084
Loans Secured by Real Estate [Member] | Other Real Estate Secured [Member] | Allowance for Credit Losses, ACL [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Collectively Evaluated for Credit Loss	3,398		4,713
Total	3,398	3,297	4,713	4,370	5,311	7,382
Loans Secured by Real Estate [Member] | Other Real Estate Secured [Member] | Allowance for Loan Losses, LHFI [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually Evaluated for Credit Loss			56
Collectively Evaluated for Credit Loss	593,119		725,987
Total	593,119		726,043
Other Loans Secured by Real Estate [Member] | Other Construction [Member] | Allowance for Credit Losses, ACL [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually Evaluated for Credit Loss	7,620
Collectively Evaluated for Credit Loss	6,299		5,968
Total	13,919	14,397	5,968	5,945	6,530	8,158
Other Loans Secured by Real Estate [Member] | Other Construction [Member] | Allowance for Loan Losses, LHFI [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually Evaluated for Credit Loss	7,620
Collectively Evaluated for Credit Loss	946,034		711,813
Total	953,654		711,813
Other Loans Secured by Real Estate [Member] | Secured by 1-4 Family Residential Properties [Member] | Allowance for Credit Losses, ACL [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Collectively Evaluated for Credit Loss	15,395		2,706
Total	15,395	$ 12,250	2,706	$ 2,654	$ 2,910	$ 5,143
Other Loans Secured by Real Estate [Member] | Secured by 1-4 Family Residential Properties [Member] | Allowance for Loan Losses, LHFI [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually Evaluated for Credit Loss	1,233		1,319
Collectively Evaluated for Credit Loss	2,028,894		1,458,991
Total	$ 2,030,127		$ 1,460,310