Other Comprehensive Income (Components Of Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands	3 Months Ended				9 Months Ended
	Sep. 30, 2017		Sep. 30, 2016		Sep. 30, 2017		Sep. 30, 2016
Unrealized (loss) gain on investment securities:
Unrealized (loss) gain on investment securities, Before-Tax Amount	$ (186)		$ (605)		$ 117		$ 860
Defined benefit pension plan adjustments:
Amortization of prior service cost, Before-Tax Amount	7	[1]	8	[1]	23	[2]	24	[2]
Amortization of actuarial loss, Before-Tax Amount	44	[1]	56	[1]	130	[2]	168	[2]
Net change, Before-Tax Amount	51		64		153		192
Other Comprehensive Income (Loss), Before-Tax Amount	(135)		(541)		270		1,052
Unrealized gain (loss) on investment securities, Income Tax (Provision) Benefit	74		229		(39)	[3]	(327)
Amortization of prior service cost, Income Tax (Provision) Benefit	(3)	[1]	(3)	[1]	(4)	[2],[3]	(9)	[2]
Amortization of actuarial loss, Income Tax (Provision) Benefit	(16)	[1]	(21)	[1]	(23)	[2],[3]	(63)	[2]
Net change, Income Tax (Provision) Benefit	(19)		(24)		(27)	[3]	(72)
Other Comprehensive Income (Loss), Income Tax (Provision) Benefit	55		205		(66)	[3]	(399)
Unrealized gain (loss) on investment securities, Net-of-Tax Amount	(112)		(376)		78		533
Amortization of prior service cost, Net-of-Tax Amount	4	[1]	5	[1]	19	[2]	15	[2]
Amortization of actuarial loss, Net-of-Tax Amount	28	[1]	35	[1]	107	[2]	105	[2]
Net change, Net-of-Tax Amount	32		40		126		120
OTHER COMPREHENSIVE INCOME (LOSS), NET OF TAX	$ (80)		$ (336)		$ 204		$ 653
Federal income tax rate					35.00%		34.00%

[1] Included in net periodic pension cost, as described in Note 9 - "Net Periodic Benefit Costs"

[2] Included in net periodic pension cost, as described in Note 9 - "Net Periodic Benefit Costs"

[3] Tax benefit includes impact of re-valuation of deferred tax asset due to increase in marginal federal income tax ratefrom 34% to 35%.