Loans and Allowance for Loan and Lease Losses (Schedule of Accretion of Purchased Impaired Loan) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2017 USD ($)
Accounts Notes Loans And Financing Receivable Gross Allowance And Net [Abstract]
Accretable yield, beginning balance	$ 67
Accretable yield amortized to interest income	(23)
Reclassification from nonaccretable difference	23	[1]
Accretable yield, ending balance	$ 67

[1] Reclassification from non-accretable difference represents an increase to the estimated cash flows to be collected on the underlying portfolio.