Income Taxes (Narrative) (Details) - USD ($) $ in Thousands		1 Months Ended		3 Months Ended									12 Months Ended
		Jan. 31, 2018	Dec. 22, 2017	Dec. 31, 2017		Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017		Dec. 31, 2016	Dec. 31, 2015
Income Taxes [Line Items]
Statutory federal tax rate													35.00%		35.00%	35.00%
Change in corporate federal statutory income tax rate			21.00%
Net operating loss carryforward	[1]			$ 76					$ 169				$ 76		$ 169
Amounts of tax benefits that would affect effective tax rate if recognized				1,464					1,225				1,464		1,225	$ 861
Income tax accrued interest				139					108				139		108	54
Increase (reduction) in accrued interest													31		54
Reduction of tax benefits over the next twelve months													299
Income tax expense				3,576	[2]	$ 2,396	$ 2,248	$ 1,665	$ 1,806	$ 1,855	$ 2,035	$ 2,020	$ 9,885	[2]	$ 7,716	$ 7,978
Percentage of pre-tax income tax rate													28.00%		24.00%	26.00%
Non-cash charge													$ 1,824
Deferred tax inventory net credit amount				462									462
Change in AOCI related to pension and unrealized gains/losses on securities available for sale													$ 2,286
Subsequent Event [Member]
Income Taxes [Line Items]
Change in corporate federal statutory income tax rate		25.00%
Minimum [Member]
Income Taxes [Line Items]
Percentage of one time charge													28.00%
Maximum [Member]
Income Taxes [Line Items]
Percentage of one time charge													25.00%
Franklin Bancorp [Member]
Income Taxes [Line Items]
Net operating loss carryforward				361									$ 361
Limitations on use				$ 122									$ 122
Net operating loss carryforward expiration date													Dec. 31, 2020

[1] As of December 31, 2017, the Company had approximately $361,000 of net operating loss carry forwards as a result of the acquisition of Franklin Bancorp. The utilization of the net operating loss carry forward is subject to Section 382 of the Internal Revenue Code and limits the Company's use to approximately $122,000 per year during the carry forward period, which expires in 2020.

[2] Includes one-time, non-cash TCJA charge of $1,824,000