Allowance For Loan Losses And Credit Quality Of Financing Receivables - Troubled Debt Restructured On Recorded Investment (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Dec. 31, 2016
Financing Receivable, Modifications [Line Items]
Total investment in troubled debt	$ 2,830	$ 2,937
Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Total investment in troubled debt	2,702	2,808
Residential Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Total investment in troubled debt	128	129
Performing [Member]
Financing Receivable, Modifications [Line Items]
Total investment in troubled debt	587	679
Performing [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Total investment in troubled debt	459	550
Performing [Member] | Residential Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Total investment in troubled debt	128	129
Non-performing [Member]
Financing Receivable, Modifications [Line Items]
Total investment in troubled debt	2,243	2,258
Non-performing [Member] | Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Total investment in troubled debt	2,243	2,258
Non-performing [Member] | Residential Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Total investment in troubled debt	$ 0	$ 0