Summary of Significant Accounting Policies - Additional Information (Details)			12 Months Ended
	Jun. 15, 2021 USD ($) $ / shares shares	Jan. 01, 2020 USD ($)	Dec. 31, 2021 USD ($) segment plan $ / shares	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)
Summary Of Significant Accounting Policies [Line Items]
Unfunded commitments to fund low-income housing partnerships			$ 43,965,000
Variable interest entity, nonconsolidated, carrying amount, assets			22,784,941,000	$ 20,603,651,000	$ 18,095,496,000
Trading securities			$ 0	0
Number of portfolio segments of loans and leases (commercial and consumer) | segment			2
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%
Preferred Stock, par value (in dollars per share) | $ / shares			$ 0.01
Net proceeds, after underwriting discounts and expenses			$ 175,487,000
Advertising costs			$ 9,600,000	8,300,000	6,100,000
Accounting Standards Update 2016-13
Summary Of Significant Accounting Policies [Line Items]
Total reserve for credit losses					$ 116,849,000
Change in Accounting Principle, Accounting Standards Update, Adoption Date			Jan. 01, 2020
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]			true
Accounting Standards Update 2016-13 | Cumulative Effect, Period of Adoption, Adjustment
Summary Of Significant Accounting Policies [Line Items]
Total reserve for credit losses		$ (5,072,000)
Increase to retained earnings		$ 3,632,000
ASU No. 2019-12
Summary Of Significant Accounting Policies [Line Items]
Change in Accounting Principle, Accounting Standards Update, Adoption Date			Dec. 15, 2020
Change in Accounting Principle, Accounting Standards Update, Adopted [true false]			true
Change in Accounting Principle, Accounting Standards Update, Immaterial Effect [true false]			true
Depositary Shares
Summary Of Significant Accounting Policies [Line Items]
Shares issued and sold | shares	7,200,000
Preferred stock, redemption price per share | $ / shares	$ 25
4.375% Fixed Rate Non-Cumulative Perpetual Preferred Stock
Summary Of Significant Accounting Policies [Line Items]
Percentage of ownership interest in share	0.025%
Series A Preferred Stock
Summary Of Significant Accounting Policies [Line Items]
Preferred stock, dividend rate, percentage per annum	4.375%
Preferred Stock, par value (in dollars per share) | $ / shares	$ 0.01
Preferred stock, liquidation preference per share | $ / shares	$ 1,000
Net proceeds, after underwriting discounts and expenses	$ 175,500,000
Preferred stock, voting rights	Holders of the Series A Preferred Stock will not have voting rights
Preferred stock, redemption price per share | $ / shares	$ 1,000
Preferred Stock, redemption date	Aug. 01, 2026
Preferred Stock, Redemption Terms	The Company may redeem the Series A Preferred Stock at its option, (i) in whole or in part, from time to time, on any dividend payment date on or after August 1, 2026 or (ii) in whole but not in part, at any time within 90 days following a regulatory capital treatment event, in either case at a redemption price equal to $1,000 per share (equivalent to $25 per depositary share), plus any declared and unpaid dividends.
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			$ 44,000,000.0	53,000,000.0
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			$ 136,600,000	$ 143,000,000.0