Loans Held for Investment (LHFI) and Allowance for Loan Losses, LHFI - Summary of Balance in Allowance for Loan Losses (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2021	Jun. 30, 2021	Mar. 31, 2021	Dec. 31, 2020
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Total	$ 103,140	$ 98,734	$ 99,457	$ 104,032	$ 109,191	$ 117,306
Allowance for Credit Losses, ACL [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually Evaluated for Credit Loss	10,905		7,625
Collectively Evaluated for Credit Loss	92,235		91,832
Total	103,140	98,734	99,457	104,032	109,191	117,306
Allowance for Loan Losses, LHFI [Member]
Financing Receivable, Allowance for Credit Loss, Additional Information [Abstract]
Individually Evaluated for Credit Loss	42,645		44,361
Collectively Evaluated for Credit Loss	10,902,195		10,203,468
Total	10,944,840		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	1,396		5,750
Collectively Evaluated for Credit Loss	12,707		13,189
Total	14,103	14,951	18,939	13,973	20,166	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	15,936		18,444
Collectively Evaluated for Credit Loss	1,535,065		1,395,835
Total	1,551,001		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	5,139		4,774
Total	5,139	4,872	4,774	4,876	4,750	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	164,001		162,555
Total	164,001		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	927		1,394
Collectively Evaluated for Credit Loss	990		1,314
Total	1,917	2,371	2,708	3,233	3,015	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	3,196		3,664
Collectively Evaluated for Credit Loss	1,107,599		1,142,587
Total	1,110,795		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	4,927		5,145
Total	4,963	4,077	5,348	7,274	6,450	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	520,597		530,235
Total	520,633		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	926		278
Collectively Evaluated for Credit Loss	6,375		5,801
Total	7,301	7,351	6,079	5,110	5,058	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	4,280		5,198
Collectively Evaluated for Credit Loss	660,537		591,770
Total	664,817		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	10,038		10,310
Total	10,038	9,867	10,310	10,399	8,667	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	493
Collectively Evaluated for Credit Loss	540,457		517,683
Total	540,950		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	29,735		37,912
Total	29,735	32,030	37,912	44,416	46,438	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	9,810		11,072
Collectively Evaluated for Credit Loss	3,168,269		2,966,012
Total	3,178,079		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	3,297		4,713
Total	3,297	3,640	4,713	5,311	5,770	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	555,311		725,987
Total	555,311		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	6,777		5,968
Total	14,397	13,947	5,968	6,530	5,124	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	767,621		711,813
Total	775,241		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	12,250		2,706
Total	12,250	$ 5,628	2,706	$ 2,910	$ 3,753	$ 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	1,274		1,319
Collectively Evaluated for Credit Loss	1,882,738		1,458,991
Total	$ 1,884,012		$ 1,460,310