Accumulated Other Comprehensive Loss (Components of Comprehensive Income) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Available for sale securities - all other: Net unrealized losses on all other AFS securities, Net of tax	$ 1,384	$ 905
Cash flow hedges: Unrealized holding (losses) gains, Before Tax	(1,315)	(432)
Cash flow hedges: Unrealized holding (losses) gains, Tax Effect	352	117
Cash flow hedges: Unrealized holding (losses) gains, Net of Tax	(963)	(315)
Unrealized net actuarial loss, Net of Tax	(4,915)	2,129
Other Comprehensive Income, Before Tax Amount	(7,692)	3,725
Other Comprehensive Income, Tax (Expense) Benefit	2,060	(1,010)
Other Comprehensive (loss) Income, Net	(5,632)	2,715
Investment securities- with OTTI [Member]
Available for sale (AFS) securities with OTTI: Unrealized holding (losses) gains, Before Tax Amount	(1,623)	(60)
Available for sale (AFS) securities with OTTI: Unrealized holding (losses) gains, tax effect	435	16
Available for sale (AFS) securities with OTTI: Unrealized holding (losses) gains, Net of Tax	(1,188)	(44)
Available for sale (AFS) securities with OTTI: Less: accretable yield recognized in income, Before Tax Amount	50	49
Available for sale (AFS) securities with OTTI: Less: accretable yield recognized in income, Tax Effect	(13)	(13)
Available for sale (AFS) securities with OTTI: Less: accretable yield recognized in income, Net of Tax	37	36
Available for sale (AFS) securities with OTTI: Net unrealized losses on investments with OTTI, Before Tax Amount	(1,673)	(109)
Available for sale (AFS) securities with OTTI: Net unrealized losses on investments with OTTI, Tax Effect	448	29
Available for sale (AFS) securities with OTTI: Net unrealized losses on investments with OTTI, Net of Tax	(1,225)	(80)
Investment Securities -All Other AFS [Member]
Securities: Unrealized holding gains, Before Tax	1,890	1,236
Securities: Unrealized holding gains, Tax Effect	(506)	(335)
Securities: Unrealized holding gains, Net of Tax	1,384	901
Less: amortization recognized in income, Before Tax		(6)
Less: amortization recognized in income,, Tax Effect		2
Less: amortization recognized in income, Net of Tax		(4)
Available for sale securities - all other: Net unrealized losses on all other AFS securities, Before Tax	1,890	1,242
Available for sale securities - all other: Net unrealized losses on all other AFS securities, Tax Effect	(506)	(337)
Available for sale securities - all other: Net unrealized losses on all other AFS securities, Net of tax	1,384	905
Investment Securities HTM [Member]
Less: amortization recognized in income, Before Tax	(72)	(75)
Less: amortization recognized in income,, Tax Effect	19	20
Less: amortization recognized in income, Net of Tax	(53)	(55)
Held to maturity securities: Net unrealized gains on all HTM securities, Before tax	72	75
Held to maturity securities: Net unrealized gains on all HTM securities, Tax	19	20
Held to maturity securities: Net unrealized gains on all HTM securities, After tax	53	55
Pension Plan [Member]
Unrealized net actuarial loss, Before Tax	(7,070)	2,652
Unrealized net actuarial loss, Tax Effect	1,893	(719)
Unrealized net actuarial loss, Net of Tax	(5,177)	1,933
Net plan liability adjustment, Before Tax	(6,712)	2,921
Net plan liability adjustment, Tax Effect	1,797	(792)
Net plan liability adjustment, Net of Tax	(4,915)	2,129
Pension Plan [Member] | Amortization of Unrecognized Loss [Member]
Less: amortization of unrecognized loss, Before Tax	(358)	(269)
Less: amortization of unrecognized loss, Tax Effect	96	73
Less: amortization of unrecognized loss, Net of Tax	(262)	(196)
SERP [Member]
Net plan liability adjustment, Before Tax	46	28
Net plan liability adjustment, Tax Effect	(12)	(7)
Net plan liability adjustment, Net of Tax	34	21
SERP [Member] | Amortization of Unrecognized Loss [Member]
Less: amortization of unrecognized loss, Before Tax	(47)	(29)
Less: amortization of unrecognized loss, Tax Effect	12	7
Less: amortization of unrecognized loss, Net of Tax	(35)	(22)
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