Loans and Allowance for Credit Losses - Age Analysis of Past Due Loans by Segment (Detail) - USD ($) $ in Thousands	Dec. 31, 2025	Dec. 31, 2024
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	$ 9,508,039	$ 8,983,754
Loans To Individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	1,457,870	1,355,974
Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	2,044,989	1,677,989
Real Estate Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	462,786	483,384
Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	2,360,285	2,341,703
Commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	3,182,109	3,124,704
Time and demand loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	1,226,054	1,133,595
Time and demand loans | Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	1,226,054	1,133,595
Commercial credit cards
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	11,408	11,718
Commercial credit cards | Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	11,408	11,718
Senior Lien
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	1,631,019	1,670,547
Senior Lien | Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	1,631,019	1,670,547
Junior Lien
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	729,266	671,156
Junior Lien | Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	729,266	671,156
Multifamily
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	594,790	597,145
Multifamily | Commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	594,790	597,145
Nonowner Occupied Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	1,834,016	1,804,950
Nonowner Occupied Commercial Real Estate | Commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	1,834,016	1,804,950
Owner Occupied Commercial Real Estate
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	753,303	722,609
Owner Occupied Commercial Real Estate | Commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	753,303	722,609
Automobile Loan
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	1,387,195	1,280,645
Automobile Loan | Loans To Individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	1,387,195	1,280,645
Consumer Credit Cards
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	9,496	9,865
Consumer Credit Cards | Loans To Individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	9,496	9,865
Other consumer loans
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	61,179	65,464
Other consumer loans | Loans To Individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	61,179	65,464
Equipment Finance
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	693,265	427,320
Equipment Finance | Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	693,265	427,320
Time and Demand Loans Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	114,262	105,356
Time and Demand Loans Other | Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	114,262	105,356
Construction Residential
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	47,250	8,017
Construction Residential | Real Estate Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	47,250	8,017
Construction Residential | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	47,250	8,017
Construction Other
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	415,536	475,367
Construction Other | Real Estate Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	415,536	475,367
Construction Other | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	415,536	475,367
Financial Asset, 30 to 59 Days Past Due [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	22,032	14,673
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	6,733	5,020
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	5,127	2,379
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	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	8,197	5,677
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	1,975	1,597
Financial Asset, 30 to 59 Days Past Due [Member] | Time and demand loans | Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	2,666	649
Financial Asset, 30 to 59 Days Past Due [Member] | Commercial credit cards | Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	75	61
Financial Asset, 30 to 59 Days Past Due [Member] | Senior Lien | Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	5,054	3,904
Financial Asset, 30 to 59 Days Past Due [Member] | Junior Lien | Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	3,143	1,773
Financial Asset, 30 to 59 Days Past Due [Member] | Multifamily | Commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	417	212
Financial Asset, 30 to 59 Days Past Due [Member] | Nonowner Occupied Commercial Real Estate | Commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	534	72
Financial Asset, 30 to 59 Days Past Due [Member] | Owner Occupied Commercial Real Estate | Commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	1,024	1,313
Financial Asset, 30 to 59 Days Past Due [Member] | Automobile Loan | Loans To Individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	6,262	4,667
Financial Asset, 30 to 59 Days Past Due [Member] | Consumer Credit Cards | Loans To Individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	50	24
Financial Asset, 30 to 59 Days Past Due [Member] | Other consumer loans | Loans To Individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	421	329
Financial Asset, 30 to 59 Days Past Due [Member] | Equipment Finance | Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	2,382	1,659
Financial Asset, 30 to 59 Days Past Due [Member] | Time and Demand Loans Other | Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	4	10
Financial Asset, 30 to 59 Days Past Due [Member] | Construction Residential | Construction
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] | Construction Other | Construction
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]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	13,760	5,445
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	1,225	1,143
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	595	1,544
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] | Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	1,870	1,659
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	10,070	1,099
Financial Asset, 60 to 89 Days Past Due [Member] | Time and demand loans | Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	125	1,126
Financial Asset, 60 to 89 Days Past Due [Member] | Commercial credit cards | Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	32	26
Financial Asset, 60 to 89 Days Past Due [Member] | Senior Lien | Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	1,456	1,184
Financial Asset, 60 to 89 Days Past Due [Member] | Junior Lien | Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	414	475
Financial Asset, 60 to 89 Days Past Due [Member] | Multifamily | Commercial real estate [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] | Nonowner Occupied Commercial Real Estate | Commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	10,070	742
Financial Asset, 60 to 89 Days Past Due [Member] | Owner Occupied Commercial Real Estate | Commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	0	357
Financial Asset, 60 to 89 Days Past Due [Member] | Automobile Loan | Loans To Individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	1,022	930
Financial Asset, 60 to 89 Days Past Due [Member] | Consumer Credit Cards | Loans To Individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	35	28
Financial Asset, 60 to 89 Days Past Due [Member] | Other consumer loans | Loans To Individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	168	185
Financial Asset, 60 to 89 Days Past Due [Member] | Equipment Finance | Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	438	392
Financial Asset, 60 to 89 Days Past Due [Member] | Time and Demand Loans Other | Commercial Loan [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] | Construction Residential | Construction
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] | Construction Other | Construction
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]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	1,288	2,064
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	490	450
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	217	26
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	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	581	1,588
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	0	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Time and demand loans | Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	107	26
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Commercial credit cards | Commercial Loan [Member]
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] | Senior Lien | Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	317	1,134
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Junior Lien | Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	264	454
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Multifamily | Commercial real estate [Member]
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] | Nonowner Occupied Commercial Real Estate | Commercial real estate [Member]
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] | Owner Occupied Commercial Real Estate | Commercial real estate [Member]
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] | Automobile Loan | Loans To Individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	168	149
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Consumer Credit Cards | Loans To Individuals [Member]
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] | Other consumer loans | Loans To Individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	322	301
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Equipment Finance | Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	110	0
Financial Asset, Equal to or Greater than 90 Days Past Due [Member] | Time and Demand Loans Other | Commercial Loan [Member]
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] | Construction Residential | Construction
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] | Construction Other | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	0	0
Nonaccrual Commercial Loans [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	91,756	61,456
Nonaccrual Commercial Loans [Member] | Loans To Individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	32	250
Nonaccrual Commercial Loans [Member] | Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	46,618	14,987
Nonaccrual Commercial Loans [Member] | Real Estate Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	1,475	2,529
Nonaccrual Commercial Loans [Member] | Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	13,019	11,587
Nonaccrual Commercial Loans [Member] | Commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	30,612	32,103
Nonaccrual Commercial Loans [Member] | Time and demand loans | Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	45,288	14,181
Nonaccrual Commercial Loans [Member] | Commercial credit cards | Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	0	0
Nonaccrual Commercial Loans [Member] | Senior Lien | Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	8,364	7,134
Nonaccrual Commercial Loans [Member] | Junior Lien | Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	4,655	4,453
Nonaccrual Commercial Loans [Member] | Multifamily | Commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	10	20
Nonaccrual Commercial Loans [Member] | Nonowner Occupied Commercial Real Estate | Commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	14,156	24,550
Nonaccrual Commercial Loans [Member] | Owner Occupied Commercial Real Estate | Commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	16,446	7,533
Nonaccrual Commercial Loans [Member] | Automobile Loan | Loans To Individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	30	147
Nonaccrual Commercial Loans [Member] | Consumer Credit Cards | Loans To Individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	0	0
Nonaccrual Commercial Loans [Member] | Other consumer loans | Loans To Individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	2	103
Nonaccrual Commercial Loans [Member] | Equipment Finance | Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	1,330	806
Nonaccrual Commercial Loans [Member] | Time and Demand Loans Other | Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	0	0
Nonaccrual Commercial Loans [Member] | Construction Residential | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	0	0
Nonaccrual Commercial Loans [Member] | Construction Other | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	1,475	2,529
Financial Asset, Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	128,836	83,638
Financial Asset, Past Due | Loans To Individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	8,480	6,863
Financial Asset, Past Due | Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	52,557	18,936
Financial Asset, Past Due | Real Estate Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	1,475	2,529
Financial Asset, Past Due | Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	23,667	20,511
Financial Asset, Past Due | Commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	42,657	34,799
Financial Asset, Past Due | Time and demand loans | Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	48,186	15,982
Financial Asset, Past Due | Commercial credit cards | Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	107	87
Financial Asset, Past Due | Senior Lien | Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	15,191	13,356
Financial Asset, Past Due | Junior Lien | Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	8,476	7,155
Financial Asset, Past Due | Multifamily | Commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	427	232
Financial Asset, Past Due | Nonowner Occupied Commercial Real Estate | Commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	24,760	25,364
Financial Asset, Past Due | Owner Occupied Commercial Real Estate | Commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	17,470	9,203
Financial Asset, Past Due | Automobile Loan | Loans To Individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	7,482	5,893
Financial Asset, Past Due | Consumer Credit Cards | Loans To Individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	85	52
Financial Asset, Past Due | Other consumer loans | Loans To Individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	913	918
Financial Asset, Past Due | Equipment Finance | Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	4,260	2,857
Financial Asset, Past Due | Time and Demand Loans Other | Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	4	10
Financial Asset, Past Due | Construction Residential | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	0	0
Financial Asset, Past Due | Construction Other | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	1,475	2,529
Financial Asset, Not Past Due
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	9,379,203	8,900,116
Financial Asset, Not Past Due | Loans To Individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	1,449,390	1,349,111
Financial Asset, Not Past Due | Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	1,992,432	1,659,053
Financial Asset, Not Past Due | Real Estate Construction [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	461,311	480,855
Financial Asset, Not Past Due | Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	2,336,618	2,321,192
Financial Asset, Not Past Due | Commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	3,139,452	3,089,905
Financial Asset, Not Past Due | Time and demand loans | Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	1,177,868	1,117,613
Financial Asset, Not Past Due | Commercial credit cards | Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	11,301	11,631
Financial Asset, Not Past Due | Senior Lien | Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	1,615,828	1,657,191
Financial Asset, Not Past Due | Junior Lien | Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	720,790	664,001
Financial Asset, Not Past Due | Multifamily | Commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	594,363	596,913
Financial Asset, Not Past Due | Nonowner Occupied Commercial Real Estate | Commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	1,809,256	1,779,586
Financial Asset, Not Past Due | Owner Occupied Commercial Real Estate | Commercial real estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	735,833	713,406
Financial Asset, Not Past Due | Automobile Loan | Loans To Individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	1,379,713	1,274,752
Financial Asset, Not Past Due | Consumer Credit Cards | Loans To Individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	9,411	9,813
Financial Asset, Not Past Due | Other consumer loans | Loans To Individuals [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	60,266	64,546
Financial Asset, Not Past Due | Equipment Finance | Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	689,005	424,463
Financial Asset, Not Past Due | Time and Demand Loans Other | Commercial Loan [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	114,258	105,346
Financial Asset, Not Past Due | Construction Residential | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	47,250	8,017
Financial Asset, Not Past Due | Construction Other | Construction
Accounts, Notes, Loans and Financing Receivable [Line Items]
Financing receivable, before allowance for credit loss	$ 414,061	$ 472,838