Comprehensive Income/Loss (Comprehensive Income/(Loss) Presented Net of Taxes) (Details) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2009
Equity [Abstract]
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification, before Tax		$ (564)	$ 182	$ (425)	$ 14
Other Comprehensive Income (Loss), Derivative, Excluded Component, Increase (Decrease), after Adjustments, Tax		159	(73)	123	(6)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), after Reclassification and Tax		(405)	109	(302)	8
Deferred Gain Loss On Cash Flow Hedge		34		34		$ 137	$ 1,400
COMPREHENSIVE INCOME
Change in fair value of securities available for sale, pre tax amount		(2,988)	347	(12,761)	2,520
Change in fair value of securities available for sale, tax (expense) benefit		726	(152)	3,107	(1,001)
Change in fair value of securities available for sale, after tax amount		(2,262)	195	(9,654)	1,519
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, before Tax		0	11	0	13
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Tax		0	(4)	0	(5)
Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI for Sale of Securities, Net of Tax		0	7	0	8
Change in fair value of securities available for sale, pre tax amount		(2,988)	336	(12,761)	2,507
Change in fair value of securities available for sale, tax (expense) benefit		726	(148)	3,107	(996)
Change in fair value of securities available for sale, after tax amount		(2,262)	188	(9,654)	1,511
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification and Tax		(296)	91	100	(250)
Other Comprehensive Income (Loss), Derivative, Excluded Component, Increase (Decrease), before Adjustments, Tax		83	(36)	(25)	102
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), before Reclassification, after Tax		(213)	55	75	(148)
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, before Tax	[1]	268	(91)	525	(264)
Other Comprehensive Income (Loss), Derivative, Excluded Component, Increase (Decrease), Adjustments, Tax	[1]	(76)	37	(148)	108
Other Comprehensive Income (Loss), Cash Flow Hedge, Gain (Loss), Reclassification, after Tax	[1]	192	(54)	377	(156)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, before Tax			(6)		(20)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, Tax			2		8
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, after Tax			(4)		(12)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, before Tax		94	69	281	208
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, Tax		(26)	(28)	(79)	(85)
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), Reclassification Adjustment from AOCI, after Tax		68	41	202	123
Amortization of certain costs included in net periodic retirement costs, pre tax amount		69	70	207	208
Amortization of certain costs included in net periodic retirement costs, tax (expense) benefit		(20)	(29)	(58)	(85)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), Reclassification Adjustment from AOCI, after Tax		49	41	149	123
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax	[2]	163	133	488	396
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, Tax	[2]	(46)	(55)	(137)	(162)
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, after Tax	[2]	117	78	351	234
Total other comprehensive income, pre tax amount		(3,389)	651	(12,698)	2,917
Total other comprehensive income, tax (expense) benefit		839	(276)	3,093	(1,164)
Total other comprehensive income, after tax amount		$ (2,550)	$ 375	$ (9,605)	$ 1,753

[1] Includes the amortization of the remaining balance of a realized but unrecognized gain, net of tax, from the termination of interest rate swaps in 2009. The original gain of $1.4 million, net of tax, is being recognized in earnings through December 2018, the original maturity date of the swap. The balance of this gain has amortized to $34,000 and $137,000 at September 30, 2018 and December 31, 2017, respectively.

[2] The amortization of prior service costs is included in the computation of net periodic pension cost as disclosed in the Employee Benefit Plans footnote in the Company's Annual Report on Form 10-K for the year ended December 31, 2017, filed with the Securities and Exchange Commission.