Loans and Allowance for Credit Losses - Allowance for Credit Losses (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	$ 133,546	$ 93,603	$ 102,906	$ 92,522
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date	0		27,205
Charge-offs	(4,598)	(3,370)	(15,824)	(7,099)
Recoveries	622	909	2,010	1,976
Provision for credit losses	4,767	4,951	18,040	8,694
Ending Balance	134,337	96,093	134,337	96,093
Time and Demand Loans
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Charge-offs			(7,424)
Recoveries			214
Commercial Credit Cards
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Charge-offs			(63)
Recoveries			13
Senior Lien
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Charge-offs			(124)
Recoveries			65
Junior Lien
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Charge-offs			(260)
Recoveries			63
Multifamily
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Charge-offs			0
Recoveries			0
Nonowner Occupied Commercial Real Estate
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Charge-offs			(172)
Recoveries			126
Owner Occupied Commercial Real Estate
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Charge-offs			(1,517)
Recoveries			16
Automobiles
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Charge-offs			(3,469)
Recoveries			1,114
Consumer Credit Cards
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Charge-offs			(205)
Recoveries			63
Other Consumer Loans
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Charge-offs			(975)
Recoveries			211
Construction Residential
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Charge-offs			0
Recoveries			0
Construction Other
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Charge-offs			0
Recoveries			0
Time and Demand Loans Other
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Charge-offs			(1,570)
Recoveries			125
Equipment Finance
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Charge-offs			(45)
Recoveries			0
Commercial, financial, agricultural and other [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	41,714	21,989	22,650	18,093
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date	0		19,417
Charge-offs	(1,762)	(852)	(9,102)	(1,836)
Recoveries	98	154	352	313
Provision for credit losses	(2,645)	1,181	4,088	5,902
Ending Balance	37,405	22,472	37,405	22,472
Commercial, financial, agricultural and other [Member] | Time and Demand Loans
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	37,873	19,921	20,040	15,283
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date	0		19,417
Charge-offs	(954)	(321)	(7,424)	(604)
Recoveries	46	77	214	155
Provision for credit losses	(3,914)	869	804	5,712
Ending Balance	33,051	20,546	33,051	20,546
Commercial, financial, agricultural and other [Member] | Commercial Credit Cards
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	320	387	335	247
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date	0		0
Charge-offs	(28)	(132)	(63)	(209)
Recoveries	6	42	13	68
Provision for credit losses	9	3	22	194
Ending Balance	307	300	307	300
Commercial, financial, agricultural and other [Member] | Time and Demand Loans Other
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	1,447	1,409	1,189	2,563
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date	0		0
Charge-offs	(780)	(399)	(1,570)	(1,023)
Recoveries	46	35	125	90
Provision for credit losses	707	12	1,676	(573)
Ending Balance	1,420	1,057	1,420	1,057
Commercial, financial, agricultural and other [Member] | Equipment Finance
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	2,074	272	1,086	0
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date	0		0
Charge-offs	0	0	(45)	0
Recoveries	0	0	0	0
Provision for credit losses	553	297	1,586	569
Ending Balance	2,627	569	2,627	569
Residential real estate [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	23,740	17,747	21,412	12,625
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date	0		527
Charge-offs	(304)	(119)	(384)	(263)
Recoveries	57	83	128	143
Provision for credit losses	447	1,592	2,257	6,798
Ending Balance	23,940	19,303	23,940	19,303
Residential real estate [Member] | Senior Lien
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	16,563	11,860	14,822	7,459
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date	0		197
Charge-offs	(107)	(79)	(124)	(124)
Recoveries	22	67	65	112
Provision for credit losses	553	1,161	2,071	5,562
Ending Balance	17,031	13,009	17,031	13,009
Residential real estate [Member] | Junior Lien
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	7,177	5,887	6,590	5,166
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date	0		330
Charge-offs	(197)	(40)	(260)	(139)
Recoveries	35	16	63	31
Provision for credit losses	(106)	431	186	1,236
Ending Balance	6,909	6,294	6,909	6,294
Commercial Real Estate [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	38,927	31,387	28,804	33,376
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date	0		6,971
Charge-offs	(172)	(1,335)	(1,689)	(1,887)
Recoveries	6	332	142	351
Provision for credit losses	4,338	(2,485)	8,871	(3,941)
Ending Balance	43,099	27,899	43,099	27,899
Commercial Real Estate [Member] | Multifamily
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	5,775	3,555	4,726	3,561
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date	0		234
Charge-offs	0	0	0	(411)
Recoveries	0	1	0	1
Provision for credit losses	46	868	861	1,273
Ending Balance	5,821	4,424	5,821	4,424
Commercial Real Estate [Member] | Nonowner Occupied Commercial Real Estate
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	21,710	20,953	16,426	24,838
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date	0		2,739
Charge-offs	(172)	(1,095)	(172)	(1,236)
Recoveries	2	330	126	340
Provision for credit losses	3,952	(4,186)	6,373	(7,940)
Ending Balance	25,492	16,002	25,492	16,002
Commercial Real Estate [Member] | Owner Occupied Commercial Real Estate
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	11,442	6,879	7,652	4,977
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date	0		3,998
Charge-offs	0	(240)	(1,517)	(240)
Recoveries	4	1	16	10
Provision for credit losses	340	833	1,637	2,726
Ending Balance	11,786	7,473	11,786	7,473
Loans to individuals [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	21,437	16,951	21,218	24,208
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date	0		3
Charge-offs	(2,360)	(1,064)	(4,649)	(3,113)
Recoveries	461	331	1,388	1,160
Provision for credit losses	1,851	3,290	3,429	(2,747)
Ending Balance	21,389	19,508	21,389	19,508
Loans to individuals [Member] | Automobiles
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	19,258	14,563	18,819	21,392
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date	0		3
Charge-offs	(1,883)	(538)	(3,469)	(1,515)
Recoveries	412	156	1,114	699
Provision for credit losses	1,503	2,979	2,823	(3,416)
Ending Balance	19,290	17,160	19,290	17,160
Loans to individuals [Member] | Consumer Credit Cards
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	375	312	412	496
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date	0		0
Charge-offs	(59)	(182)	(205)	(415)
Recoveries	16	15	63	53
Provision for credit losses	38	244	100	255
Ending Balance	370	389	370	389
Loans to individuals [Member] | Other Consumer Loans
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	1,804	2,076	1,987	2,320
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date	0		0
Charge-offs	(418)	(344)	(975)	(1,183)
Recoveries	33	160	211	408
Provision for credit losses	310	67	506	414
Ending Balance	1,729	1,959	1,729	1,959
Real estate construction [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	7,728	5,529	8,822	4,220
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date	0		287
Charge-offs	0	0	0	0
Recoveries	0	9	0	9
Provision for credit losses	776	1,373	(605)	2,682
Ending Balance	8,504	6,911	8,504	6,911
Real estate construction [Member] | Construction Residential
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	1,583	1,929	2,462	942
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date	0		60
Charge-offs	0	0	0	0
Recoveries	0	0	0	0
Provision for credit losses	(431)	(41)	(1,370)	946
Ending Balance	1,152	1,888	1,152	1,888
Real estate construction [Member] | Construction Other
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	6,145	3,600	6,360	3,278
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date	0		227
Charge-offs	0	0	0	0
Recoveries	0	9	0	9
Provision for credit losses	1,207	1,414	765	1,736
Ending Balance	$ 7,352	$ 5,023	$ 7,352	$ 5,023