Loans And Allowance For Credit Losses (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Dec. 31, 2024
Financing Receivable, Allowance for Credit Loss [Line Items]
Pledged Financial Instruments, Not Separately Reported, Loans Receivable, for Federal Home Loan Bank Debt	$ 3,300,000
Pledged Financial Instruments, Not Separately Reported, Loans Receivable, for Federal Reserve Bank Debt	2,600,000
Financing Receivable, Nonaccrual, No Allowance	5,900		$ 2,000
Commitments to lend additional funds to customers with restructured loans	$ 11,800		14,900
Period after which loans are deemed in default (in days)	90 days
Residential mortgage loans held for sale	$ 2,702		2,981
Unpaid Principal Balance on Personal Real Estate Loans Held for Sale	2,700
HFS Loans on non accrual status	0
HFS loans 90 days past due and still accruing	0
Foreclosed real estate	642		343
Residential Real Estate Acquired Through Foreclosure through Obtaining Physical Possession	642		343
Personal property acquired in repossession	2,300		2,200
Loans Receivable
Financing Receivable, Allowance for Credit Loss [Line Items]
Accrued Interest Receivable	66,200		70,600
Accrued Interest Receivable	66,200		$ 70,600
Commercial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Accrued Interest, Writeoff	112	$ 94
Personal Banking Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Accrued Interest, Writeoff	$ 1,700	$ 1,600