Loans and Allowance for Credit Losses - Allowance for Credit Losses (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022	Jun. 30, 2023	Jun. 30, 2022
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	$ 133,885	$ 91,188	$ 102,906	$ 92,522
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date	5,126		27,205
Charge-offs	(9,343)	(2,106)	(11,226)	(3,729)
Recoveries	678	578	1,388	1,067
Provision for credit losses	3,200	3,943	13,273	3,743
Ending Balance	133,546	93,603	133,546	93,603
Time and Demand Loans
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Charge-offs			(6,470)
Recoveries			168
Commercial Credit Cards
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Charge-offs			(35)
Recoveries			7
Senior Lien
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Charge-offs			(17)
Recoveries			43
Junior Lien
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Charge-offs			(63)
Recoveries			28
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			0
Recoveries			124
Owner Occupied Commercial Real Estate
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Charge-offs			(1,517)
Recoveries			12
Automobiles
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Charge-offs			(1,586)
Recoveries			702
Consumer Credit Cards
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Charge-offs			(146)
Recoveries			47
Other Consumer Loans
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Charge-offs			(557)
Recoveries			178
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			(790)
Recoveries			79
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	42,568	20,721	22,650	18,093
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date	3,468		19,417
Charge-offs	(6,677)	(509)	(7,340)	(984)
Recoveries	95	79	254	159
Provision for credit losses	2,260	1,698	6,733	4,721
Ending Balance	41,714	21,989	41,714	21,989
Commercial, financial, agricultural and other [Member] | Time and Demand Loans
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	39,465	18,907	20,040	15,283
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date	3,468		19,417
Charge-offs	(6,215)	(139)	(6,470)	(283)
Recoveries	52	25	168	78
Provision for credit losses	1,103	1,128	4,718	4,843
Ending Balance	37,873	19,921	37,873	19,921
Commercial, financial, agricultural and other [Member] | Commercial Credit Cards
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	331	342	335	247
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date	0		0
Charge-offs	(9)	(58)	(35)	(77)
Recoveries	5	25	7	26
Provision for credit losses	(7)	78	13	191
Ending Balance	320	387	320	387
Commercial, financial, agricultural and other [Member] | Time and Demand Loans Other
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	1,311	1,441	1,189	2,563
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date	0		0
Charge-offs	(453)	(312)	(790)	(624)
Recoveries	38	29	79	55
Provision for credit losses	551	251	969	(585)
Ending Balance	1,447	1,409	1,447	1,409
Commercial, financial, agricultural and other [Member] | Equipment Finance
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	1,461	31	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	613	241	1,033	272
Ending Balance	2,074	272	2,074	272
Residential real estate [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	22,773	16,728	21,412	12,625
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date	0		527
Charge-offs	(1)	(5)	(80)	(144)
Recoveries	33	31	71	60
Provision for credit losses	935	993	1,810	5,206
Ending Balance	23,740	17,747	23,740	17,747
Residential real estate [Member] | Senior Lien
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	15,824	11,125	14,822	7,459
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date	0		197
Charge-offs	(1)	(5)	(17)	(45)
Recoveries	17	22	43	45
Provision for credit losses	723	718	1,518	4,401
Ending Balance	16,563	11,860	16,563	11,860
Residential real estate [Member] | Junior Lien
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	6,949	5,603	6,590	5,166
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date	0		330
Charge-offs	0	0	(63)	(99)
Recoveries	16	9	28	15
Provision for credit losses	212	275	292	805
Ending Balance	7,177	5,887	7,177	5,887
Commercial Real Estate [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	39,377	33,704	28,804	33,376
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date	1,658		6,971
Charge-offs	(1,517)	(552)	(1,517)	(552)
Recoveries	94	5	136	19
Provision for credit losses	(685)	(1,770)	4,533	(1,456)
Ending Balance	38,927	31,387	38,927	31,387
Commercial Real Estate [Member] | Multifamily
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	5,541	3,610	4,726	3,561
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date	0		234
Charge-offs	0	(411)	0	(411)
Recoveries	0	0	0	0
Provision for credit losses	234	356	815	405
Ending Balance	5,775	3,555	5,775	3,555
Commercial Real Estate [Member] | Nonowner Occupied Commercial Real Estate
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	21,552	23,267	16,426	24,838
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date	0		2,739
Charge-offs	0	(141)	0	(141)
Recoveries	86	5	124	10
Provision for credit losses	72	(2,178)	2,421	(3,754)
Ending Balance	21,710	20,953	21,710	20,953
Commercial Real Estate [Member] | Owner Occupied Commercial Real Estate
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	12,284	6,827	7,652	4,977
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date	1,658		3,998
Charge-offs	(1,517)	0	(1,517)	0
Recoveries	8	0	12	9
Provision for credit losses	(991)	52	1,297	1,893
Ending Balance	11,442	6,879	11,442	6,879
Loans to individuals [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	21,218	15,105	21,218	24,208
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date	0		3
Charge-offs	(1,148)	(1,040)	(2,289)	(2,049)
Recoveries	456	463	927	829
Provision for credit losses	911	2,423	1,578	(6,037)
Ending Balance	21,437	16,951	21,437	16,951
Loans to individuals [Member] | Automobiles
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	19,013	12,635	18,819	21,392
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date	0		3
Charge-offs	(784)	(425)	(1,586)	(977)
Recoveries	312	288	702	543
Provision for credit losses	717	2,065	1,320	(6,395)
Ending Balance	19,258	14,563	19,258	14,563
Loans to individuals [Member] | Consumer Credit Cards
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	368	382	412	496
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date	0		0
Charge-offs	(80)	(124)	(146)	(233)
Recoveries	30	14	47	38
Provision for credit losses	57	40	62	11
Ending Balance	375	312	375	312
Loans to individuals [Member] | Other Consumer Loans
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	1,837	2,088	1,987	2,320
Financing Receivable, Purchased with Credit Deterioration, Allowance for Credit Loss at Acquisition Date	0		0
Charge-offs	(284)	(491)	(557)	(839)
Recoveries	114	161	178	248
Provision for credit losses	137	318	196	347
Ending Balance	1,804	2,076	1,804	2,076
Real estate construction [Member]
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	7,949	4,930	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	0	0	0
Provision for credit losses	(221)	599	(1,381)	1,309
Ending Balance	7,728	5,529	7,728	5,529
Real estate construction [Member] | Construction Residential
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	2,058	1,755	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	(475)	174	(939)	987
Ending Balance	1,583	1,929	1,583	1,929
Real estate construction [Member] | Construction Other
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	5,891	3,175	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	0	0	0
Provision for credit losses	254	425	(442)	322
Ending Balance	$ 6,145	$ 3,600	$ 6,145	$ 3,600