Loans and Allowance for Credit Losses for Loans - Amortized Cost per Loan Class Based on Payment Activity by Origination Year (Details) - USD ($) $ in Thousands	Dec. 31, 2021	Dec. 31, 2020
Financing Receivable, Credit Quality Indicator [Line Items]
Total	$ 34,153,657	$ 32,217,112
90 Days or More Past Due Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	2,771	13,541
Residential mortgage
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	1,448,602	730,764
Year two, fiscal year before current fiscal year	635,888	781,246
Year three, two years before current fiscal year	575,538	688,973
Year four, three years before current fiscal year	427,208	586,114
Year five, four years before current fiscal year	370,958	384,867
More than five years before current fiscal year	1,016,528	946,981
Revolving Loans Amortized Cost Basis	70,342	64,798
Revolving Loans Converted to Term Loans	0	0
Total	4,545,064	4,183,743
Residential mortgage | 90 Days or More Past Due Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	677	3,170
Residential mortgage | Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	1,448,602	730,764
Year two, fiscal year before current fiscal year	635,531	778,161
Year three, two years before current fiscal year	572,911	684,761
Year four, three years before current fiscal year	425,152	582,650
Year five, four years before current fiscal year	368,164	380,723
More than five years before current fiscal year	1,014,190	943,616
Revolving Loans Amortized Cost Basis	70,342	64,798
Revolving Loans Converted to Term Loans	0	0
Total	4,534,892	4,165,473
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	357	3,085
Year three, two years before current fiscal year	2,627	4,212
Year four, three years before current fiscal year	2,056	3,464
Year five, four years before current fiscal year	2,794	4,144
More than five years before current fiscal year	2,338	3,365
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans	0	0
Total	10,172	18,270
Consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	752,371	446,991
Year two, fiscal year before current fiscal year	322,296	454,481
Year three, two years before current fiscal year	292,368	290,819
Year four, three years before current fiscal year	172,014	161,744
Year five, four years before current fiscal year	79,202	57,330
More than five years before current fiscal year	43,367	37,456
Revolving Loans Amortized Cost Basis	1,265,942	1,200,000
Revolving Loans Converted to Term Loans	43,416	52,017
Total	2,970,976	2,700,838
Consumer | Home equity
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	13,847	8,580
Year two, fiscal year before current fiscal year	5,723	10,634
Year three, two years before current fiscal year	6,994	11,756
Year four, three years before current fiscal year	7,384	8,886
Year five, four years before current fiscal year	5,359	5,365
More than five years before current fiscal year	13,632	15,476
Revolving Loans Amortized Cost Basis	304,424	319,247
Revolving Loans Converted to Term Loans	43,416	51,609
Total	400,779	431,553
Consumer | Automobile
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	735,575	426,140
Year two, fiscal year before current fiscal year	309,856	438,289
Year three, two years before current fiscal year	278,906	272,248
Year four, three years before current fiscal year	157,613	151,746
Year five, four years before current fiscal year	72,834	50,888
More than five years before current fiscal year	15,252	16,644
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans	0	0
Total	1,570,036	1,355,955
Consumer | Other consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	2,949	12,271
Year two, fiscal year before current fiscal year	6,717	5,558
Year three, two years before current fiscal year	6,468	6,815
Year four, three years before current fiscal year	7,017	1,112
Year five, four years before current fiscal year	1,009	1,077
More than five years before current fiscal year	14,483	5,336
Revolving Loans Amortized Cost Basis	961,518	880,753
Revolving Loans Converted to Term Loans	0	408
Total	1,000,161	913,330
Consumer | 90 Days or More Past Due Loans
Financing Receivable, Credit Quality Indicator [Line Items]
Total	789	271
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	271	245
Consumer | 90 Days or More Past Due Loans | Other consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Total	518	26
Consumer | Performing | Home equity
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	13,847	8,580
Year two, fiscal year before current fiscal year	5,723	10,634
Year three, two years before current fiscal year	6,994	11,756
Year four, three years before current fiscal year	7,384	8,886
Year five, four years before current fiscal year	5,359	5,340
More than five years before current fiscal year	13,597	15,393
Revolving Loans Amortized Cost Basis	303,888	318,869
Revolving Loans Converted to Term Loans	42,822	50,879
Total	399,614	430,337
Consumer | Performing | Automobile
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	735,446	426,121
Year two, fiscal year before current fiscal year	309,856	438,181
Year three, two years before current fiscal year	278,828	272,075
Year four, three years before current fiscal year	157,450	151,523
Year five, four years before current fiscal year	72,753	50,853
More than five years before current fiscal year	15,171	16,550
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans	0	0
Total	1,569,504	1,355,303
Consumer | Performing | Other consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	2,949	12,271
Year two, fiscal year before current fiscal year	6,717	5,558
Year three, two years before current fiscal year	6,468	6,815
Year four, three years before current fiscal year	7,017	1,112
Year five, four years before current fiscal year	1,009	1,077
More than five years before current fiscal year	14,483	5,314
Revolving Loans Amortized Cost Basis	961,027	880,748
Revolving Loans Converted to Term Loans	0	0
Total	999,670	912,895
Consumer | 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	0	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	25
More than five years before current fiscal year	35	83
Revolving Loans Amortized Cost Basis	536	378
Revolving Loans Converted to Term Loans	594	730
Total	1,165	1,216
Consumer | Non-Performing Loans | 90 Days or More Past Due Loans | Automobile
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	129	19
Year two, fiscal year before current fiscal year	0	108
Year three, two years before current fiscal year	78	173
Year four, three years before current fiscal year	163	223
Year five, four years before current fiscal year	81	35
More than five years before current fiscal year	81	94
Revolving Loans Amortized Cost Basis	0	0
Revolving Loans Converted to Term Loans	0	0
Total	532	652
Consumer | Non-Performing Loans | 90 Days or More Past Due Loans | Other consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Year one, current fiscal year	0	0
Year two, fiscal year before current fiscal year	0	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	0	22
Revolving Loans Amortized Cost Basis	491	5
Revolving Loans Converted to Term Loans	0	408
Total	$ 491	$ 435