Loans and Allowance for Credit Losses (Narrative) (Details)	12 Months Ended
	Dec. 31, 2023 USD ($) Loan	Dec. 31, 2022 USD ($) Loan	Dec. 31, 2021 USD ($) Loan	Jul. 03, 2023 USD ($)
Accounts Notes And Loans Receivable [Line Items]
Accrued interest	$ 124,700,000	$ 100,200,000
Related party balances of loans	23,500,000	30,400,000
Related party new loans	4,500,000
Related party repayments	11,400,000
Short-term borrowings	$ 1,154,829,000	$ 1,871,271,000
Percentage of baseline economic forecast	40.00%
Weighted average percentage of forecast		25.00%
Loans held for sale (includes $13,269 and $10,853 measured at fair value)	$ 26,124,000	$ 26,385,000
Provision for credit losses	59,103,000	(28,399,000)	$ (77,494,000)
Nonaccrual loans	$ 59,036,000	38,991,000
Real estate in process of foreclosure		26,400,000
Description of post modification defaults	A payment default occurs if the loan is either 90 days or more delinquent or has been charged off as of the end of the period presented
Libor Transition [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans receivable				$ 3,100,000,000
Modified Loans To Borrowers Experiencing Financial Difficulty [Member]
Accounts Notes And Loans Receivable [Line Items]
Nonaccrual loans	$ 100,000
Accruing and nonaccruing	24,500,000
Unfunded commitment to borrowers related to MEFD or TDR	$ 700,000
Troubled Debt Restructurings [Member]
Accounts Notes And Loans Receivable [Line Items]
Nonaccrual loans		2,600,000
Accruing and nonaccruing		4,500,000
Reduced interest rate		100,000	500,000
Unfunded commitment to borrowers related to MEFD or TDR		0
Troubled Debt Restructurings [Member] | Loans With Extended Amortization Terms Or Other Payment Concessions [Member]
Accounts Notes And Loans Receivable [Line Items]
Extended terms and other payment concessions			7,100,000
Troubled Debt Restructurings [Member] | Loans With Other Modifications [Member]
Accounts Notes And Loans Receivable [Line Items]
Other modifications			$ 1,200,000
Troubled Debt Restructurings [Member] | Loans With Other Modifications [Member]
Accounts Notes And Loans Receivable [Line Items]
Other modifications		$ 100,000
Downside Recessionary S-2 [Member]
Accounts Notes And Loans Receivable [Line Items]
Weighted average percentage of forecast		75.00%
Downside Mild Recessionary S-2 [Member]
Accounts Notes And Loans Receivable [Line Items]
Percentage of baseline economic forecast	60.00%
FHLB Borrowings [Member]
Accounts Notes And Loans Receivable [Line Items]
Short-term borrowings	$ 700,000,000	$ 1,425,000,000
Weighted Average [Member]
Accounts Notes And Loans Receivable [Line Items]
Weighted average interest rate reduction, basis points	0.80%
Weighted Average [Member] | Other Than Insignificant Payment Delays [Member]
Accounts Notes And Loans Receivable [Line Items]
Reportable modification period	3 months
Residential Mortgages [Member]
Accounts Notes And Loans Receivable [Line Items]
Nonaccrual loans	$ 26,137,000	$ 25,269,000
Loans carried at fair value option	13,300,000
Unpaid principal balance	$ 12,900,000
Residential Mortgages [Member] | Troubled Debt Restructurings [Member]
Accounts Notes And Loans Receivable [Line Items]
Number of TDRs subsequently defaulted | Loan		3	1
Recorded Investment		$ 200,000	$ 600,000
Residential Mortgages [Member] | Weighted Average [Member] | Term Extension [Member]
Accounts Notes And Loans Receivable [Line Items]
Reportable modification period	10 years
Consumer [Member]
Accounts Notes And Loans Receivable [Line Items]
Nonaccrual loans	$ 8,555,000	6,692,000
Real estate in process of foreclosure	7,100,000	4,900,000
Real estate acquired through foreclosure	$ 1,600,000	$ 400,000
Consumer [Member] | Troubled Debt Restructurings [Member]
Accounts Notes And Loans Receivable [Line Items]
Number of TDRs subsequently defaulted | Loan		3
Recorded Investment		$ 300,000
Consumer [Member] | Weighted Average [Member] | Term Extension [Member]
Accounts Notes And Loans Receivable [Line Items]
Reportable modification period	8 years
Commercial Portfolio Segment [Member] | Troubled Debt Restructurings [Member]
Accounts Notes And Loans Receivable [Line Items]
Recorded Investment			7,200,000
Commercial Portfolio Segment [Member] | Weighted Average [Member] | Term Extension [Member]
Accounts Notes And Loans Receivable [Line Items]
Reportable modification period	10 months
Residential and Consumer Portfolio Segment [Member] | Troubled Debt Restructurings [Member]
Accounts Notes And Loans Receivable [Line Items]
Recorded Investment			$ 1,600,000
Total Commercial And Industrial [Member] | Commercial Portfolio Segment [Member]
Accounts Notes And Loans Receivable [Line Items]
Nonaccrual loans	$ 23,068,000	$ 5,481,000
Commercial Non Real Estate [Member] | Troubled Debt Restructurings [Member]
Accounts Notes And Loans Receivable [Line Items]
Number of TDRs subsequently defaulted | Loan		3	4
Recorded Investment		$ 3,100,000
Commercial Non Real Estate [Member] | Consumer [Member]
Accounts Notes And Loans Receivable [Line Items]
Number of TDRs subsequently defaulted | Loan	1
Recorded Investment	$ 4,400,000
Commercial Non Real Estate [Member] | Total Commercial And Industrial [Member] | Commercial Portfolio Segment [Member]
Accounts Notes And Loans Receivable [Line Items]
Nonaccrual loans	$ 20,840,000	$ 4,020,000