Loans, Allowance for Loan Losses and Credit Quality (Activity in the Accretable Yield for PCI loans) (Details) - USD ($) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2018		Jun. 30, 2017		Jun. 30, 2018	Jun. 30, 2017
Certain Loans Acquired in Transfer Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Certain Loans Acquired in Transfer Accounted for as Debt Securities, Accretable Yield, Beginning of Period	$ 1,642		$ 2,279		$ 1,791	$ 2,370
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield, Accretion	(198)		(302)		(413)	(609)
Certainloansacquiredinatransfernotaccountedforasdebtsecuritiesaccretableyieldadjustmentchangesinexpectedcashflow	160	[1]	190	[1]	204	406
Certain Loans Acquired in Transfer Accounted for as Debt Securities, Accretable Yield, Reclassifications from Nonaccretable Difference	0	[2]	18	[2]	22	18
Certain Loans Acquired in Transfer Accounted for as Debt Securities, Accretable Yield, End of Period	$ 1,604		$ 2,185		$ 1,604	$ 2,185

[1] (1) Represents changes in cash flows expected to be collected and resulting in increased interest income as a prospective yield adjustment over the remaining life of the loan(s).

[2] (2) Results in increased interest income during the period in which the loan paid off at amount greater than originally expected.