Loans, Allowance for Loan Losses and Credit Quality (Modifications which occurred during the period & change in recorded investment) (Details) $ in Thousands		3 Months Ended
		Mar. 31, 2019 USD ($) contract	Mar. 31, 2018 USD ($) contract
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | contract		2	3
TROUBLED DEBT RESTRUCTURINGS:
Financing Receivable, Modifications, Pre-Modification Recorded Investment		$ 225	$ 687
Financing Receivable, Modifications, Post-Modification Recorded Investment	[1]	$ 225	$ 687
Commercial Real Estate [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | contract		1	1
TROUBLED DEBT RESTRUCTURINGS:
Financing Receivable, Modifications, Pre-Modification Recorded Investment		$ 150	$ 445
Financing Receivable, Modifications, Post-Modification Recorded Investment	[1]	$ 150	$ 445
Consumer Home Equity [Member]
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Number of Contracts | contract		1	2
TROUBLED DEBT RESTRUCTURINGS:
Financing Receivable, Modifications, Pre-Modification Recorded Investment		$ 75	$ 242
Financing Receivable, Modifications, Post-Modification Recorded Investment	[1]	$ 75	$ 242

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