Accumulated Other Comprehensive Loss (Components of Comprehensive Income) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Available for sale securities - all other: Net unrealized losses on all other AFS securities, Net of tax	$ 608	$ 1,577	$ 1,992	$ 2,482
Cash flow hedges: Unrealized holding (losses) gains, Net of Tax	(81)	(486)	(1,044)	(801)
Unrealized net actuarial loss, Net of Tax	3,399	707	(1,516)	2,836
Other Comprehensive Income, Before Tax Amount	5,626		(2,064)	6,041
Other Comprehensive Income, Tax (Expense) Benefit	(1,506)		552	(1,638)
Other Comprehensive (loss) Income, Net	4,120		(1,512)	4,403
Investment securities- with OTTI [Member]
Available for sale (AFS) securities with OTTI: Unrealized holding (losses) gains, Before Tax Amount	(333)	(216)	(1,956)	(276)
Available for sale (AFS) securities with OTTI: Unrealized holding (losses) gains, tax effect	89	59	524	75
Available for sale (AFS) securities with OTTI: Unrealized holding (losses) gains, Net of Tax	(244)	(157)	(1,432)	(201)
Available for sale (AFS) securities with OTTI: Less: accretable yield recognized in income, Before Tax Amount	51	50	101	99
Available for sale (AFS) securities with OTTI: Less: accretable yield recognized in income, Tax Effect	(14)	(13)	(27)	(26)
Available for sale (AFS) securities with OTTI: Less: accretable yield recognized in income, Net of Tax	37	37	74	73
Available for sale (AFS) securities with OTTI: Net unrealized losses on investments with OTTI, Before Tax Amount	(384)	(266)	(2,057)	(375)
Available for sale (AFS) securities with OTTI: Net unrealized losses on investments with OTTI, Tax Effect	103	72	551	101
Available for sale (AFS) securities with OTTI: Net unrealized losses on investments with OTTI, Net of Tax	(281)	(194)	(1,506)	(274)
Investment Securities -All Other AFS [Member]
Securities: Unrealized holding gains, Before Tax	877	2,169	2,767	3,405
Securities: Unrealized holding gains, Tax Effect	(235)	(588)	(741)	(923)
Securities: Unrealized holding gains, Net of Tax	642	1,581	2,026	2,482
Less: amortization recognized in income, Before Tax	47	6	47
Less: amortization recognized in income, Tax Effect	(13)	(2)	(13)
Less: amortization recognized in income, Net of Tax	34	4	34
Available for sale securities - all other: Net unrealized losses on all other AFS securities, Before Tax	830	2,163	2,720	3,405
Available for sale securities - all other: Net unrealized losses on all other AFS securities, Tax Effect	(222)	(586)	(728)	(923)
Available for sale securities - all other: Net unrealized losses on all other AFS securities, Net of tax	608	1,577	1,992	2,482
Investment Securities HTM [Member]
Less: amortization recognized in income, Before Tax	60	(86)	60	(161)
Less: amortization recognized in income, Tax Effect	(16)	23	(16)	43
Less: amortization recognized in income, Net of Tax	44	(63)	44	(118)
Held to maturity securities: Net unrealized gains on all HTM securities, Before tax	602	86	675	161
Held to maturity securities: Net unrealized gains on all HTM securities, Tax	(161)	(23)	(181)	(43)
Held to maturity securities: Net unrealized gains on all HTM securities, After tax	441	63	494	118
Investment Securities HTM [Member] | Amortization of Recognized Income [Member]
Less: amortization recognized in income, Before Tax	(662)		(735)
Less: amortization recognized in income, Tax Effect	177		197
Less: amortization recognized in income, Net of Tax	(485)		(538)
Cash Flow Hedge (OCI) [Member]
Cash flow hedges: Unrealized holding (losses) gains, Before Tax	(111)	(666)	(1,425)	(1,098)
Cash flow hedges: Unrealized holding (losses) gains, Tax Effect	30	180	381	297
Cash flow hedges: Unrealized holding (losses) gains, Net of Tax	(81)	(486)	(1,044)	(801)
Pension Plan [Member]
Unrealized net actuarial loss, Before Tax	4,284	701	(2,786)	(3,353)
Unrealized net actuarial loss, Tax Effect	(1,147)	(190)	746	(909)
Unrealized net actuarial loss, Net of Tax	3,137	511	(2,040)	(2,444)
Net plan liability adjustment, Before Tax	4,642	970	(2,070)	3,891
Net plan liability adjustment, Tax Effect	(1,243)	(263)	554	(1,055)
Net plan liability adjustment, Net of Tax	3,399	707	(1,516)	2,836
Pension Plan [Member] | Amortization of Unrecognized Loss [Member]
Less: amortization of unrecognized loss, Before Tax	(358)	(269)	(716)	(538)
Less: amortization of unrecognized loss, Tax Effect	96	73	192	146
Less: amortization of unrecognized loss, Net of Tax	(262)	(196)	(524)	(392)
SERP [Member]
Net plan liability adjustment, Before Tax	47	29	93	57
Net plan liability adjustment, Tax Effect	(13)	(8)	(25)	(15)
Net plan liability adjustment, Net of Tax	34	21	68	42
Other Comprehensive Income, Before Tax Amount		2,316
Other Comprehensive Income, Tax (Expense) Benefit		(628)
Other Comprehensive (loss) Income, Net		1,688
SERP [Member] | Amortization of Unrecognized Loss [Member]
Less: amortization of unrecognized loss, Before Tax	(47)	(29)	(94)	(58)
Less: amortization of unrecognized loss, Tax Effect	13	8	25	15
Less: amortization of unrecognized loss, Net of Tax	$ (34)	$ (21)	(69)	(43)
SERP [Member] | Amortization of Prior Service Costs [Member]
Less: amortization of prior service costs, Before Tax			1	1
Less: amortization of prior service costs, Net of Tax			$ 1	$ 1