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, 2023	Dec. 31, 2022
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 50,210,295	$ 46,917,200
Gross loan charge-offs
Total	75,453	41,896
90 Days or More Past Due Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	13,145	26,587
Residential mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	467,178	1,302,279
Year two, fiscal year before current fiscal year	1,305,994	1,502,819
Year three, two years before current fiscal year	1,506,814	571,607
Year four, three years before current fiscal year	540,210	502,032
Year five, four years before current fiscal year	439,060	340,938
More than five years before current fiscal year	1,250,931	1,078,169
Revolving Loans Amortized Cost Basis	57,052	66,706
Revolving Loans Converted to Term Loans	1,771	0
Total	5,569,010	5,364,550
Gross loan charge-offs
Total	194	28
Residential mortgage | 90 Days or More Past Due Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	2,488	1,866
Residential mortgage | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	467,178	1,302,279
Year two, fiscal year before current fiscal year	1,304,026	1,502,622
Year three, two years before current fiscal year	1,505,133	571,390
Year four, three years before current fiscal year	538,853	500,197
Year five, four years before current fiscal year	435,669	338,062
More than five years before current fiscal year	1,244,986	1,073,995
Revolving Loans Amortized Cost Basis	57,052	66,706
Revolving Loans Converted to Term Loans	1,771	0
Total	5,554,668	5,355,251
Residential mortgage | Non-Performing Loans | 90 Days or More Past Due Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	0	0
Year two, fiscal year before current fiscal year	1,968	197
Year three, two years before current fiscal year	1,681	217
Year four, three years before current fiscal year	1,357	1,835
Year five, four years before current fiscal year	3,391	2,876
More than five years before current fiscal year	5,945	4,174
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans	0	0
Total	14,342	9,299
Home equity
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	541,513	795,819
Year two, fiscal year before current fiscal year	597,411	547,709
Year three, two years before current fiscal year	374,145	217,412
Year four, three years before current fiscal year	127,568	178,742
Year five, four years before current fiscal year	101,615	93,100
More than five years before current fiscal year	135,506	74,268
Revolving Loans Amortized Cost Basis	1,538,050	1,368,622
Revolving Loans Converted to Term Loans	24,887	39,280
Total	3,440,695	3,314,952
Gross loan charge-offs
Total	4,298	4,057
Home equity | Home equity
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	40,599	47,084
Year two, fiscal year before current fiscal year	44,944	12,432
Year three, two years before current fiscal year	14,961	4,592
Year four, three years before current fiscal year	4,096	5,024
Year five, four years before current fiscal year	4,850	5,581
More than five years before current fiscal year	47,406	13,007
Revolving Loans Amortized Cost Basis	396,960	376,884
Revolving Loans Converted to Term Loans	5,336	39,280
Total	559,152	503,884
Home equity | Automobile
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	468,242	724,595
Year two, fiscal year before current fiscal year	532,012	525,133
Year three, two years before current fiscal year	356,198	204,614
Year four, three years before current fiscal year	121,750	166,283
Year five, four years before current fiscal year	86,384	80,113
More than five years before current fiscal year	34,813	45,487
Revolving Loans Amortized Cost Basis	20,227	0
Revolving Loans Converted to Term Loans	763	0
Total	1,620,389	1,746,225
Home equity | Other consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	32,672	24,140
Year two, fiscal year before current fiscal year	20,455	10,144
Year three, two years before current fiscal year	2,986	8,206
Year four, three years before current fiscal year	1,722	7,435
Year five, four years before current fiscal year	10,381	7,406
More than five years before current fiscal year	53,287	15,774
Revolving Loans Amortized Cost Basis	1,120,863	991,738
Revolving Loans Converted to Term Loans	18,788	0
Total	1,261,154	1,064,843
Home equity | 90 Days or More Past Due Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	1,088	47
Home equity | 90 Days or More Past Due Loans | Home equity
Financing Receivable, Credit Quality Indicator [Line Items]
Total	0	0
Home equity | 90 Days or More Past Due Loans | Automobile
Financing Receivable, Credit Quality Indicator [Line Items]
Total	576	1
Home equity | 90 Days or More Past Due Loans | Other consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Total	512	46
Home equity | Performing | Home equity
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	40,599	47,084
Year two, fiscal year before current fiscal year	44,893	12,432
Year three, two years before current fiscal year	14,948	4,592
Year four, three years before current fiscal year	4,096	5,024
Year five, four years before current fiscal year	4,850	5,581
More than five years before current fiscal year	46,274	13,007
Revolving Loans Amortized Cost Basis	396,960	376,608
Revolving Loans Converted to Term Loans	4,608	38,570
Total	557,228	502,898
Home equity | Performing | Automobile
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	468,152	724,557
Year two, fiscal year before current fiscal year	531,728	525,017
Year three, two years before current fiscal year	356,144	204,578
Year four, three years before current fiscal year	121,658	166,103
Year five, four years before current fiscal year	86,147	80,012
More than five years before current fiscal year	34,504	45,415
Revolving Loans Amortized Cost Basis	20,227	0
Revolving Loans Converted to Term Loans	763	0
Total	1,619,323	1,745,682
Home equity | Performing | Other consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	32,662	24,140
Year two, fiscal year before current fiscal year	20,376	10,144
Year three, two years before current fiscal year	2,986	8,206
Year four, three years before current fiscal year	1,722	7,435
Year five, four years before current fiscal year	10,381	7,406
More than five years before current fiscal year	52,659	15,736
Revolving Loans Amortized Cost Basis	1,120,863	991,737
Revolving Loans Converted to Term Loans	18,655	0
Total	1,260,304	1,064,804
Home equity | Non-Performing 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	51	0
Year three, two years before current fiscal year	13	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	1,132	0
Revolving Loans Amortized Cost Basis	0	276
Revolving Loans Converted to Term Loans	728	710
Total	1,924	986
Home equity | Non-Performing Loans | 90 Days or More Past Due Loans | Automobile
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	90	38
Year two, fiscal year before current fiscal year	284	116
Year three, two years before current fiscal year	54	36
Year four, three years before current fiscal year	92	180
Year five, four years before current fiscal year	237	101
More than five years before current fiscal year	309	72
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans	0	0
Total	1,066	543
Home equity | Non-Performing Loans | 90 Days or More Past Due Loans | Other consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	10	0
Year two, fiscal year before current fiscal year	79	0
Year three, two years before current fiscal year	0	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	628	38
Revolving Loans Amortized Cost Basis	0	1
Revolving Loans Converted to Term Loans	133	0
Total	850	$ 39
Residential Mortgage and Consumer
Gross loan charge-offs
2023	296
2022	903
2021	357
2020	232
2019	752
Prior to 2019	1,921
Revolving Loans Amortized Cost Basis	31
Revolving Loans Converted to Term Loans	0
Total	$ 4,492