Loans and Allowance for Credit Losses for Loans - Amortized Cost per Loan Class Based on Payment Activity by Origination Year (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 48,799,711	$ 50,210,295
Gross loan charge-offs
Total	215,112	75,453
90 Days or More Past Due Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	5,889	13,145
Residential mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	428,668	467,178
Year two, fiscal year before current fiscal year	414,299	1,305,994
Year three, two years before current fiscal year	1,283,554	1,506,814
Year four, three years before current fiscal year	1,422,368	540,210
Year five, four years before current fiscal year	499,716	439,060
More than five years before current fiscal year	1,506,797	1,250,931
Revolving Loans Amortized Cost Basis	75,479	57,052
Revolving Loans Converted to Term Loans	1,635	1,771
Total	5,632,516	5,569,010
Gross loan charge-offs
Total	29	194
Residential mortgage | 90 Days or More Past Due Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	3,533	2,488
Residential mortgage | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	428,138	467,178
Year two, fiscal year before current fiscal year	413,528	1,304,026
Year three, two years before current fiscal year	1,282,524	1,505,133
Year four, three years before current fiscal year	1,420,835	538,853
Year five, four years before current fiscal year	494,430	435,669
More than five years before current fiscal year	1,490,512	1,244,986
Revolving Loans Amortized Cost Basis	75,479	57,052
Revolving Loans Converted to Term Loans	954	1,771
Total	5,606,400	5,554,668
Residential mortgage | Nonperforming financial loans | 90 Days or More Past Due Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	530	0
Year two, fiscal year before current fiscal year	771	1,968
Year three, two years before current fiscal year	1,030	1,681
Year four, three years before current fiscal year	1,533	1,357
Year five, four years before current fiscal year	5,286	3,391
More than five years before current fiscal year	16,285	5,945
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans	681	0
Total	26,116	14,342
Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	901,463	541,513
Year two, fiscal year before current fiscal year	398,761	597,411
Year three, two years before current fiscal year	418,714	374,145
Year four, three years before current fiscal year	223,255	127,568
Year five, four years before current fiscal year	62,967	101,615
More than five years before current fiscal year	165,116	135,506
Revolving Loans Amortized Cost Basis	1,395,156	1,538,050
Revolving Loans Converted to Term Loans	25,405	24,887
Total	3,590,837	3,440,695
Gross loan charge-offs
Total	8,289	4,298
Consumer | Home equity
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	22,947	40,599
Year two, fiscal year before current fiscal year	29,493	44,944
Year three, two years before current fiscal year	38,825	14,961
Year four, three years before current fiscal year	10,303	4,096
Year five, four years before current fiscal year	3,340	4,850
More than five years before current fiscal year	51,468	47,406
Revolving Loans Amortized Cost Basis	438,817	396,960
Revolving Loans Converted to Term Loans	9,240	5,336
Total	604,433	559,152
Consumer | Automobile
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	863,352	468,242
Year two, fiscal year before current fiscal year	343,325	532,012
Year three, two years before current fiscal year	364,041	356,198
Year four, three years before current fiscal year	211,364	121,750
Year five, four years before current fiscal year	59,290	86,384
More than five years before current fiscal year	59,693	34,813
Revolving Loans Amortized Cost Basis	0	20,227
Revolving Loans Converted to Term Loans	0	763
Total	1,901,065	1,620,389
Consumer | Other consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	15,164	32,672
Year two, fiscal year before current fiscal year	25,943	20,455
Year three, two years before current fiscal year	15,848	2,986
Year four, three years before current fiscal year	1,588	1,722
Year five, four years before current fiscal year	337	10,381
More than five years before current fiscal year	53,955	53,287
Revolving Loans Amortized Cost Basis	956,339	1,120,863
Revolving Loans Converted to Term Loans	16,165	18,788
Total	1,085,339	1,261,154
Consumer | 90 Days or More Past Due Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	1,049	1,088
Consumer | 90 Days or More Past Due Loans | Home equity
Financing Receivable, Credit Quality Indicator [Line Items]
Total	0	0
Consumer | 90 Days or More Past Due Loans | Automobile
Financing Receivable, Credit Quality Indicator [Line Items]
Total	407	576
Consumer | 90 Days or More Past Due Loans | Other consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Total	642	512
Consumer | Performing | Home equity
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	22,947	40,599
Year two, fiscal year before current fiscal year	29,445	44,893
Year three, two years before current fiscal year	38,774	14,948
Year four, three years before current fiscal year	10,302	4,096
Year five, four years before current fiscal year	3,340	4,850
More than five years before current fiscal year	50,613	46,274
Revolving Loans Amortized Cost Basis	438,817	396,960
Revolving Loans Converted to Term Loans	9,061	4,608
Total	603,299	557,228
Consumer | Performing | Automobile
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	863,281	468,152
Year two, fiscal year before current fiscal year	343,203	531,728
Year three, two years before current fiscal year	363,901	356,144
Year four, three years before current fiscal year	211,294	121,658
Year five, four years before current fiscal year	59,288	86,147
More than five years before current fiscal year	59,512	34,504
Revolving Loans Amortized Cost Basis	0	20,227
Revolving Loans Converted to Term Loans	0	763
Total	1,900,479	1,619,323
Consumer | Performing | Other consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	15,164	32,662
Year two, fiscal year before current fiscal year	25,884	20,376
Year three, two years before current fiscal year	15,787	2,986
Year four, three years before current fiscal year	1,588	1,722
Year five, four years before current fiscal year	337	10,381
More than five years before current fiscal year	53,917	52,659
Revolving Loans Amortized Cost Basis	956,339	1,120,863
Revolving Loans Converted to Term Loans	15,917	18,655
Total	1,084,933	1,260,304
Consumer | Nonperforming financial loans | 90 Days or More Past Due Loans | Home equity
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	0	0
Year two, fiscal year before current fiscal year	48	51
Year three, two years before current fiscal year	51	13
Year four, three years before current fiscal year	1	0
Year five, four years before current fiscal year	0	0
More than five years before current fiscal year	855	1,132
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans	179	728
Total	1,134	1,924
Consumer | Nonperforming financial loans | 90 Days or More Past Due Loans | Automobile
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	71	90
Year two, fiscal year before current fiscal year	122	284
Year three, two years before current fiscal year	140	54
Year four, three years before current fiscal year	70	92
Year five, four years before current fiscal year	2	237
More than five years before current fiscal year	181	309
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans	0	0
Total	586	1,066
Consumer | Nonperforming financial loans | 90 Days or More Past Due Loans | Other consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	0	10
Year two, fiscal year before current fiscal year	59	79
Year three, two years before current fiscal year	61	0
Year four, three years before current fiscal year	0	0
Year five, four years before current fiscal year	0	0
More than five years before current fiscal year	38	628
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans	248	133
Total	406	850
Residential Mortgage and Consumer
Gross loan charge-offs
Year one, gross loan charge-offs	1,014	296
Year two, gross loan charge-offs	1,883	903
Year three, gross loan charge-offs	1,511	357
Year four, gross loan charge-offs	1,015	232
Year five, gross loan charge-offs	519	752
More than five years gross loan charge-offs	2,245	1,921
Revolving Loans Amortized Cost Basis	0	31
Revolving Loans Converted to Term Loans	131	0
Total	$ 8,318	$ 4,492