Loans and Allowance for Credit Losses (Narrative) (Details)	12 Months Ended
	Dec. 31, 2022 USD ($) Loan	Dec. 31, 2021 USD ($) Loan	Dec. 31, 2020 USD ($) Loan
Accounts Notes And Loans Receivable [Line Items]
Accrued interest	$ 100,200,000	$ 67,800,000
Related party balances of loans	30,400,000	62,900,000
Related party new loans	3,000,000.0
Related party repayments	35,300,000
Short-term borrowings	$ 1,871,271,000	$ 1,665,061,000
Percentage of baseline economic forecast	25.00%
Weighted average percentage of forecast		40.00%
Loans held for sale (includes $10,853 and $41,022 measured at fair value)	$ 26,385,000	$ 93,069,000
Provision for credit losses	(28,399,000)	(77,494,000)	$ 602,904,000
Nonaccrual loans	38,991,000	55,523,000
TDRs both accruing and nonaccruing	4,500,000	10,600,000
Unfunded commitment to borrowers related to modified TDR	0	0
Troubled Debt Restructurings [Member]
Accounts Notes And Loans Receivable [Line Items]
Nonaccrual loans	2,600,000	6,800,000
Reduced interest rate	100,000	500,000	1,100,000
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	1,000,000.0
Troubled Debt Restructurings [Member] | Loans With Other Modifications [Member]
Accounts Notes And Loans Receivable [Line Items]
Other modifications	$ 100,000	$ 1,200,000	2,100,000
Troubled Debt Restructurings [Member] | Loans With Significant Covenant Waivers [Member]
Accounts Notes And Loans Receivable [Line Items]
Covenant waivers			$ 400,000
Slower Near Term Growth S-2 [Member]
Accounts Notes And Loans Receivable [Line Items]
Weighted average percentage of forecast		60.00%
Downside Recessionary S-2 [Member]
Accounts Notes And Loans Receivable [Line Items]
Percentage of baseline economic forecast	75.00%
FHLB Borrowings [Member]
Accounts Notes And Loans Receivable [Line Items]
Short-term borrowings	$ 1,425,000,000	$ 1,100,000,000
Residential Mortgages [Member]
Accounts Notes And Loans Receivable [Line Items]
Nonaccrual loans	25,269,000	$ 25,439,000
Loans carried at fair value option	10,800,000
Unpaid principal balance	$ 10,600,000
Residential Mortgages [Member] | Troubled Debt Restructurings [Member]
Accounts Notes And Loans Receivable [Line Items]
Number of TDRs subsequently defaulted | Loan	2	1	2
Recorded Investment		$ 600,000	$ 800,000
Consumer [Member]
Accounts Notes And Loans Receivable [Line Items]
Nonaccrual loans	$ 6,692,000	11,887,000
Real estate in process of foreclosure	4,900,000	4,400,000
Real estate acquired through foreclosure	$ 400,000	2,400,000
Consumer [Member] | Troubled Debt Restructurings [Member]
Accounts Notes And Loans Receivable [Line Items]
Number of TDRs subsequently defaulted | Loan	4		1
Recorded Investment	$ 300,000		$ 100,000
Total Commercial And Industrial [Member] | Total Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Nonaccrual loans	5,481,000	11,895,000
Commercial Non Real Estate [Member]
Accounts Notes And Loans Receivable [Line Items]
Paycheck protection program loans	$ 38,800,000	531,100,000
Commercial Non Real Estate [Member] | Troubled Debt Restructurings [Member]
Accounts Notes And Loans Receivable [Line Items]
Number of TDRs subsequently defaulted | Loan	3		2
Recorded Investment	$ 3,100,000		$ 13,400,000
Commercial Non Real Estate [Member] | Total Commercial And Industrial [Member] | Total Commercial [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans interest bearing rate	1.00%
Loans receivable percentage of origination fee description	These loans also earn an origination fee of 1%, 3%, or 5%, depending on the loan size
Nonaccrual loans	$ 4,020,000	$ 6,974,000
Commercial Non Real Estate [Member] | Total Commercial And Industrial [Member] | Total Commercial [Member] | Minimum [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans term	2 years
Loans percentage of origination fee	1.00%
Commercial Non Real Estate [Member] | Total Commercial And Industrial [Member] | Total Commercial [Member] | Maximum [Member]
Accounts Notes And Loans Receivable [Line Items]
Loans term	5 years
Loans percentage of origination fee	5.00%