Loans and Allowance for Credit Losses - Age Analysis of Past Due Loans by Segment (Detail) - USD ($) $ in Thousands	Jun. 30, 2022	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 7,119,754	$ 6,839,230
Commercial, financial, agricultural and other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	1,170,583	1,173,452
Commercial, financial, agricultural and other [Member] | Time and Demand Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	1,031,930	1,159,524
Commercial, financial, agricultural and other [Member] | Commercial Credit Cards
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	16,329	13,928
Commercial, financial, agricultural and other [Member] | Time and Demand Loans Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	101,262
Commercial, financial, agricultural and other [Member] | Equipment Finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	21,062
Real estate construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	392,992	494,456
Real estate construction [Member] | Construction Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	100,592
Real estate construction [Member] | Construction Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	292,400
Residential real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	2,100,201	1,920,250
Residential real estate [Member] | Senior Lien
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	1,459,861	1,299,534
Residential real estate [Member] | Junior Lien
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	640,340	620,716
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	2,319,094	2,251,097
Commercial Real Estate [Member] | Multifamily
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	360,335	385,432
Commercial Real Estate [Member] | Nonowner Occupied Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	1,510,804	1,465,247
Commercial Real Estate [Member] | Owner Occupied Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	447,955	400,418
Loans to individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	1,136,884	999,975
Loans to individuals [Member] | Automobiles
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	1,047,104	901,280
Loans to individuals [Member] | Consumer Credit Cards
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	8,717	11,151
Loans to individuals [Member] | Other Consumer Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	81,063	87,544
Financial Asset, 30 to 59 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	4,844	6,450
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial, financial, agricultural and other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	121	633
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial, financial, agricultural and other [Member] | Time and Demand Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	14	605
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial, financial, agricultural and other [Member] | Commercial Credit Cards
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	107	28
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial, financial, agricultural and other [Member] | Time and Demand Loans Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial, financial, agricultural and other [Member] | Equipment Finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
Financial Asset, 30 to 59 Days Past Due [Member] | Real estate construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	0	813
Financial Asset, 30 to 59 Days Past Due [Member] | Real estate construction [Member] | Construction Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
Financial Asset, 30 to 59 Days Past Due [Member] | Real estate construction [Member] | Construction Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
Financial Asset, 30 to 59 Days Past Due [Member] | Residential real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	2,382	3,393
Financial Asset, 30 to 59 Days Past Due [Member] | Residential real estate [Member] | Senior Lien
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	1,503	1,934
Financial Asset, 30 to 59 Days Past Due [Member] | Residential real estate [Member] | Junior Lien
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	879	1,459
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	76	0
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Real Estate [Member] | Multifamily
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	76	0
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Real Estate [Member] | Nonowner Occupied Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	0	0
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Real Estate [Member] | Owner Occupied Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	0	0
Financial Asset, 30 to 59 Days Past Due [Member] | Loans to individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	2,265	1,611
Financial Asset, 30 to 59 Days Past Due [Member] | Loans to individuals [Member] | Automobiles
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	1,855	1,228
Financial Asset, 30 to 59 Days Past Due [Member] | Loans to individuals [Member] | Consumer Credit Cards
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	82	36
Financial Asset, 30 to 59 Days Past Due [Member] | Loans to individuals [Member] | Other Consumer Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	328	347
Financial Asset, 60 to 89 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	1,811	2,461
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial, financial, agricultural and other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	34	987
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial, financial, agricultural and other [Member] | Time and Demand Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	30	972
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial, financial, agricultural and other [Member] | Commercial Credit Cards
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	4	15
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial, financial, agricultural and other [Member] | Time and Demand Loans Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial, financial, agricultural and other [Member] | Equipment Finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
Financial Asset, 60 to 89 Days Past Due [Member] | Real estate construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	0	0
Financial Asset, 60 to 89 Days Past Due [Member] | Real estate construction [Member] | Construction Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
Financial Asset, 60 to 89 Days Past Due [Member] | Real estate construction [Member] | Construction Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
Financial Asset, 60 to 89 Days Past Due [Member] | Residential real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	1,217	983
Financial Asset, 60 to 89 Days Past Due [Member] | Residential real estate [Member] | Senior Lien
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	661	354
Financial Asset, 60 to 89 Days Past Due [Member] | Residential real estate [Member] | Junior Lien
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	556	629
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	33	74
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Real Estate [Member] | Multifamily
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	0	0
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Real Estate [Member] | Nonowner Occupied Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	0	0
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Real Estate [Member] | Owner Occupied Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	33	74
Financial Asset, 60 to 89 Days Past Due [Member] | Loans to individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	527	417
Financial Asset, 60 to 89 Days Past Due [Member] | Loans to individuals [Member] | Automobiles
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	326	175
Financial Asset, 60 to 89 Days Past Due [Member] | Loans to individuals [Member] | Consumer Credit Cards
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	65	44
Financial Asset, 60 to 89 Days Past Due [Member] | Loans to individuals [Member] | Other Consumer Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	136	198
Non Accrual Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	29,288	48,060
Non Accrual Loans [Member] | Commercial, financial, agricultural and other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	1,668	2,006
Non Accrual Loans [Member] | Commercial, financial, agricultural and other [Member] | Time and Demand Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	1,668	2,006
Non Accrual Loans [Member] | Commercial, financial, agricultural and other [Member] | Commercial Credit Cards
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	0	0
Non Accrual Loans [Member] | Commercial, financial, agricultural and other [Member] | Time and Demand Loans Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
Non Accrual Loans [Member] | Commercial, financial, agricultural and other [Member] | Equipment Finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
Non Accrual Loans [Member] | Real estate construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	0	45
Non Accrual Loans [Member] | Real estate construction [Member] | Construction Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
Non Accrual Loans [Member] | Real estate construction [Member] | Construction Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
Non Accrual Loans [Member] | Residential real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	5,369	5,608
Non Accrual Loans [Member] | Residential real estate [Member] | Senior Lien
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	2,721	2,706
Non Accrual Loans [Member] | Residential real estate [Member] | Junior Lien
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	2,648	2,902
Non Accrual Loans [Member] | Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	21,952	40,195
Non Accrual Loans [Member] | Commercial Real Estate [Member] | Multifamily
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	0	15,097
Non Accrual Loans [Member] | Commercial Real Estate [Member] | Nonowner Occupied Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	20,764	23,930
Non Accrual Loans [Member] | Commercial Real Estate [Member] | Owner Occupied Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	1,188	1,168
Non Accrual Loans [Member] | Loans to individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	299	206
Non Accrual Loans [Member] | Loans to individuals [Member] | Automobiles
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	225	148
Non Accrual Loans [Member] | Loans to individuals [Member] | Consumer Credit Cards
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	0	0
Non Accrual Loans [Member] | Loans to individuals [Member] | Other Consumer Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	74	58
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	3,155	1,606
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial, financial, agricultural and other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	699	155
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial, financial, agricultural and other [Member] | Time and Demand Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	613	144
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial, financial, agricultural and other [Member] | Commercial Credit Cards
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	82	11
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial, financial, agricultural and other [Member] | Time and Demand Loans Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	4
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial, financial, agricultural and other [Member] | Equipment Finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Real estate construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	0	448
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Real estate construction [Member] | Construction Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Real estate construction [Member] | Construction Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Residential real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	920	218
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Residential real estate [Member] | Senior Lien
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	447	51
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Residential real estate [Member] | Junior Lien
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	473	167
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	1,002	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Real Estate [Member] | Multifamily
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Real Estate [Member] | Nonowner Occupied Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	1,002	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Real Estate [Member] | Owner Occupied Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Loans to individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	534	785
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Loans to individuals [Member] | Automobiles
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	100	199
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Loans to individuals [Member] | Consumer Credit Cards
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	46	63
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Loans to individuals [Member] | Other Consumer Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	388	523
Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	39,098	58,577
Financial Asset, Past Due | Commercial, financial, agricultural and other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	2,522	3,781
Financial Asset, Past Due | Commercial, financial, agricultural and other [Member] | Time and Demand Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	2,325	3,727
Financial Asset, Past Due | Commercial, financial, agricultural and other [Member] | Commercial Credit Cards
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	193	54
Financial Asset, Past Due | Commercial, financial, agricultural and other [Member] | Time and Demand Loans Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	4
Financial Asset, Past Due | Commercial, financial, agricultural and other [Member] | Equipment Finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
Financial Asset, Past Due | Real estate construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	0	1,306
Financial Asset, Past Due | Real estate construction [Member] | Construction Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
Financial Asset, Past Due | Real estate construction [Member] | Construction Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	0
Financial Asset, Past Due | Residential real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	9,888	10,202
Financial Asset, Past Due | Residential real estate [Member] | Senior Lien
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	5,332	5,045
Financial Asset, Past Due | Residential real estate [Member] | Junior Lien
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	4,556	5,157
Financial Asset, Past Due | Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	23,063	40,269
Financial Asset, Past Due | Commercial Real Estate [Member] | Multifamily
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	76	15,097
Financial Asset, Past Due | Commercial Real Estate [Member] | Nonowner Occupied Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	21,766	23,930
Financial Asset, Past Due | Commercial Real Estate [Member] | Owner Occupied Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	1,221	1,242
Financial Asset, Past Due | Loans to individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	3,625	3,019
Financial Asset, Past Due | Loans to individuals [Member] | Automobiles
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	2,506	1,750
Financial Asset, Past Due | Loans to individuals [Member] | Consumer Credit Cards
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	193	143
Financial Asset, Past Due | Loans to individuals [Member] | Other Consumer Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	926	1,126
Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	7,080,656	6,780,653
Financial Asset, Not Past Due | Commercial, financial, agricultural and other [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	1,168,061	1,169,671
Financial Asset, Not Past Due | Commercial, financial, agricultural and other [Member] | Time and Demand Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	1,029,605	1,155,797
Financial Asset, Not Past Due | Commercial, financial, agricultural and other [Member] | Commercial Credit Cards
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	16,136	13,874
Financial Asset, Not Past Due | Commercial, financial, agricultural and other [Member] | Time and Demand Loans Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	101,258
Financial Asset, Not Past Due | Commercial, financial, agricultural and other [Member] | Equipment Finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	21,062
Financial Asset, Not Past Due | Real estate construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	392,992	493,150
Financial Asset, Not Past Due | Real estate construction [Member] | Construction Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	100,592
Financial Asset, Not Past Due | Real estate construction [Member] | Construction Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	292,400
Financial Asset, Not Past Due | Residential real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	2,090,313	1,910,048
Financial Asset, Not Past Due | Residential real estate [Member] | Senior Lien
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	1,454,529	1,294,489
Financial Asset, Not Past Due | Residential real estate [Member] | Junior Lien
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	635,784	615,559
Financial Asset, Not Past Due | Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	2,296,031	2,210,828
Financial Asset, Not Past Due | Commercial Real Estate [Member] | Multifamily
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	360,259	370,335
Financial Asset, Not Past Due | Commercial Real Estate [Member] | Nonowner Occupied Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	1,489,038	1,441,317
Financial Asset, Not Past Due | Commercial Real Estate [Member] | Owner Occupied Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	446,734	399,176
Financial Asset, Not Past Due | Loans to individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	1,133,259	996,956
Financial Asset, Not Past Due | Loans to individuals [Member] | Automobiles
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	1,044,598	899,530
Financial Asset, Not Past Due | Loans to individuals [Member] | Consumer Credit Cards
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	8,524	11,008
Financial Asset, Not Past Due | Loans to individuals [Member] | Other Consumer Loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing Receivable, before Allowance for Credit Loss	$ 80,137	$ 86,418