Summary Of Significant Accounting Policies (Narrative) (Details) shares in Thousands	12 Months Ended
	Dec. 31, 2016 store item shares	Dec. 31, 2015 shares	Dec. 31, 2014 shares
Summary Of Significant Accounting Policies [Line Items]
Number of banking offices \| store	14
Loan returned to accrual status period	6 months
Number of reporting units \| item	1
Total anti-dilutive stock options, in shares \| shares	60	86	43
Residential Real Estate And Home Equity Loans [Member]
Summary Of Significant Accounting Policies [Line Items]
Loan non-accrual status period	90 days
Consumer Loans [Member]
Summary Of Significant Accounting Policies [Line Items]
Loan non-accrual status period	90 days
Loan charged-off period	120 days
Commercial Real Estate And Commercial Business Loans [Member]
Summary Of Significant Accounting Policies [Line Items]
Loan non-accrual status period	90 days
Minimum [Member] \| Land and Building [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life	25 years
Minimum [Member] \| Furniture And Equipment [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life	3 years
Maximum [Member] \| Land and Building [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life	40 years
Maximum [Member] \| Furniture And Equipment [Member]
Summary Of Significant Accounting Policies [Line Items]
Property, plant and equipment, useful life	7 years