Loans And Allowance For Credit Losses (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025	Dec. 31, 2025
Financing Receivable, Allowance for Credit Loss [Line Items]
Pledged Financial Instruments, Not Separately Reported, Loans Receivable, for Federal Home Loan Bank Debt	$ 3,700,000
Pledged Financial Instruments, Not Separately Reported, Loans Receivable, for Federal Reserve Bank Debt	2,700,000
Financing Receivable, Nonaccrual, No Allowance	9,100		$ 0
Commitments to lend additional funds to customers with restructured loans	$ 13,300		11,400
Period after which loans are deemed in default (in days)	90 days
Residential mortgage loans held for sale	$ 1,657		4,028
Unpaid Principal Balance on Personal Real Estate Loans Held for Sale	1,600
HFS Loans on non accrual status	0
HFS loans 90 days past due and still accruing	0
Foreclosed real estate	678		1,200
Residential Real Estate Acquired Through Foreclosure through Obtaining Physical Possession	678		1,000
Personal property acquired in repossession	2,800		2,300
Loans Receivable
Financing Receivable, Allowance for Credit Loss [Line Items]
Accrued Interest Receivable	78,900		74,400
Accrued Interest Receivable	78,900		$ 74,400
Commercial Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Accrued Interest, Writeoff	39	$ 112
Personal Banking Portfolio Segment [Member]
Financing Receivable, Allowance for Credit Loss [Line Items]
Financing Receivable, Accrued Interest, Writeoff	$ 1,600	$ 1,700