Summary of Significant Accounting Policies - Additional Information (Details)	12 Months Ended
	Dec. 31, 2022 USD ($) plan	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Unfunded commitments to fund low-income housing partnerships	$ 88,759,000
Variable interest entity, nonconsolidated, carrying amount, assets	23,606,877,000	$ 22,784,941,000	$ 20,603,651,000
Trading securities	$ 0	0
Period during which non-accrual loan that has been modified in a troubled debt restructuring remains on non-accrual status (in months)	6 months
Maximum original maturity period of cash and cash equivalents (in days)	90 days
Goodwill impairment	$ 0
Number of company's pension plans | plan	2
Minimum percentage of net actuarial gain (loss) will be amortized in net periodic benefit cost	10.00%
Minimum percentage of likelihood of tax position being realized upon ultimate settlement according to management's judgment	50.00%
Advertising costs	$ 10,000,000.0	9,600,000	$ 8,300,000
Maximum | Building
Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives (in years)	30 years
Maximum | Equipment
Summary Of Significant Accounting Policies [Line Items]
Estimated useful lives (in years)	10 years
Home Equity
Summary Of Significant Accounting Policies [Line Items]
Minimum maturity period to be considered to place loans and leases on non-accrual status (in days)	120 days
Home Equity | Maximum
Summary Of Significant Accounting Policies [Line Items]
Combined loan-to-value ratio, considered in determining whether the entire outstanding balance on the loan is to be charged-off or not (as a percent)	60.00%
Commercial
Summary Of Significant Accounting Policies [Line Items]
Minimum maturity period to be considered to place loans and leases on non-accrual status (in days)	90 days
Residential Mortgage and Home Equity Loan
Summary Of Significant Accounting Policies [Line Items]
Minimum maturity period to be considered to place loans and leases on non-accrual status (in days)	120 days
Automobile and Other consumer
Summary Of Significant Accounting Policies [Line Items]
Minimum maturity period to be considered for loans and leases to be charged off (in days)	120 days
Commercial and Industrial
Summary Of Significant Accounting Policies [Line Items]
Minimum maturity period to be considered for loans and leases to be charged off (in days)	120 days
Other Liabilities
Summary Of Significant Accounting Policies [Line Items]
Unfunded commitments to fund low-income housing partnerships	$ 88,800,000	44,000,000.0
Low-income Housing Partnerships
Summary Of Significant Accounting Policies [Line Items]
Period over which Federal tax credits or benefits are generally recognized (in years)	10 years
Period over which State tax credits or benefits are generally recognized (in years)	5 years
Solar Energy Partnerships
Summary Of Significant Accounting Policies [Line Items]
Period over which Federal tax credits or benefits are generally recognized (in years)	6 years
Variable Interest Entity Nonconsolidated | Other Assets
Summary Of Significant Accounting Policies [Line Items]
Variable interest entity, nonconsolidated, carrying amount, assets	$ 175,300,000	$ 136,600,000