Accumulated Other Comprehensive Loss (Components of Comprehensive Income) (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended		12 Months Ended
	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Net unrealized gains (losses), before tax	$ (4,523)			$ (9,447)			$ (5,957)	$ (34,845)
Income tax benefit/(expense) related to other comprehensive income	1,060			2,529			1,410	9,325
Other comprehensive (loss)/income, net of tax	(3,463)	$ (1,153)	$ 69	(6,918)	$ (9,009)	$ (9,593)	(4,547)	(25,520)
Accumulated Other Comprehensive Loss [Member]
Unrealized net gains (losses), net of tax	(3,748)	(1,435)	(210)						$ (13,133)
Recognized gains (losses), net of tax	(285)	(282)	(279)						(1,421)
Other comprehensive (loss)/income, net of tax	(3,463)	(1,153)	69	(6,918)	$ (9,009)	$ (9,593)
Investment securities- with OTTI [Member]
Unrealized holding (losses)/gains on investments	633			(199)			(777)	(853)
Recognized gains (losses), before tax	51			51			152	152
Net unrealized gains (losses), before tax	582			(250)			(929)	(1,005)
Unrealized tax (expense) benefit	(158)			53			183	228
Income tax benefit/(expense) related to other comprehensive income	(145)			67			220	269
Unrealized net gains (losses), net of tax	475	111	(1,180)	(146)			(594)	(625)	(614)
Recognized gains (losses), net of tax	38	40	37						148
Other comprehensive (loss)/income, net of tax	437			(183)			(709)	(736)
Investment securities- with OTTI [Member] | Accretable Yield in Income [Member]
Recognized gains (losses), before tax	51			51			152	152
Recognized tax (expense) benefit	(13)			(14)			(37)	(41)
Recognized gains (losses), net of tax	38			37			115	111
Investment securities- all other [Member]
Unrealized holding (losses)/gains on investments				(6,768)			(5,065)	(22,971)
Recognized gains (losses), before tax	(4,183)			(6,768)				3
Net unrealized gains (losses), before tax	(4,183)			(6,768)			(5,065)	(14,646)
Unrealized tax (expense) benefit				1,811				6,147
Income tax benefit/(expense) related to other comprehensive income	982			1,811			1,195	3,920
Unrealized net gains (losses), net of tax				(4,957)				(16,824)
Other comprehensive (loss)/income, net of tax	(3,201)			(4,957)			(3,870)	(10,726)
Investment securities- all other [Member] | Recognition of Gains (Losses) In Income [Member]
Recognized gains (losses), before tax								3
Recognized tax (expense) benefit								(1)
Recognized gains (losses), net of tax								2
Investment Securities HTM [Member]
Unrealized holding (losses)/gains on investments								(8,328)
Recognized gains (losses), before tax	(167)			(320)			(513)	(644)
Net unrealized gains (losses), before tax	167			227			513	(7,777)
Unrealized tax (expense) benefit								2,228
Income tax benefit/(expense) related to other comprehensive income	(37)			(60)			(121)	2,081
Unrealized net gains (losses), net of tax								(6,100)	(6,120)
Recognized gains (losses), net of tax	(130)	(129)	(133)						(551)
Other comprehensive (loss)/income, net of tax	130			167			392	(5,696)
Investment Securities HTM [Member] | Recognition of Gains (Losses) In Income [Member]
Recognized gains (losses), before tax				93				93
Recognized tax (expense) benefit				(25)				(25)
Recognized gains (losses), net of tax				68				68
Investment Securities HTM [Member] | Amortization of Recognized Income [Member]
Recognized gains (losses), before tax	(167)			(320)			(513)	(644)
Recognized tax (expense) benefit	37			85			121	172
Recognized gains (losses), net of tax	(130)			(235)			(392)	(472)
Investment Securities Transferred From AFS to HTM
Unrealized holding (losses)/gains on investments								8,328
Unrealized tax (expense) benefit								(2,228)
Unrealized net gains (losses), net of tax								6,100
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member]
Net unrealized gains (losses), before tax	14			534			30	1,622
Income tax benefit/(expense) related to other comprehensive income	(3)			(142)			(7)	(434)
Unrealized net gains (losses), net of tax	11	150	(138)						1,116
Other comprehensive (loss)/income, net of tax	11			392			23	1,188
Adjustment [Member]
Unrealized holding (losses)/gains on investments	(1,352)			(3,537)			(1,250)	(14,079)
Recognized gains (losses), before tax	(251)			(279)			(750)	(837)
Net unrealized gains (losses), before tax	(1,101)			(3,258)			(500)	(13,242)
Adjustment [Member] | Pension [Member]
Unrealized holding (losses)/gains on investments	(1,352)			(3,537)			(1,250)	(14,079)
Net unrealized gains (losses), before tax	(1,101)			(3,258)			(500)	(13,242)
Unrealized tax (expense) benefit	319			945			298	3,767
Income tax benefit/(expense) related to other comprehensive income	262			871			121	3,543
Unrealized net gains (losses), net of tax	(1,033)	(42)	123	(2,592)			(952)	(10,312)	684
Recognized gains (losses), net of tax	(194)	(195)	(184)						(821)
Other comprehensive (loss)/income, net of tax	(839)			(2,387)			(379)	(9,699)
Adjustment [Member] | SERP [Member]
Net unrealized gains (losses), before tax	(2)			68			(6)	203
Income tax benefit/(expense) related to other comprehensive income	1			(18)			2	(54)
Unrealized net gains (losses), net of tax									2,430
Recognized gains (losses), net of tax	1	$ 2	$ 1						$ (199)
Other comprehensive (loss)/income, net of tax	(1)			50			(4)	149
Adjustment [Member] | Amortization of Unrecognized Loss [Member] | Pension [Member]
Recognized gains (losses), before tax	(251)			(279)			(750)	(837)
Recognized tax (expense) benefit	57			74			177	224
Recognized gains (losses), net of tax	(194)			(205)			(573)	(613)
Adjustment [Member] | Amortization of Unrecognized Loss [Member] | SERP [Member]
Recognized gains (losses), before tax	2			(68)			6	(203)
Recognized tax (expense) benefit	(1)			18			(2)	54
Recognized gains (losses), net of tax	$ 1			$ (50)			$ 4	$ (149)