Accumulated Other Comprehensive Loss (Components of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2024	Jun. 30, 2024	Mar. 31, 2024	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Sep. 30, 2024	Sep. 30, 2023
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	$ 467,667	$ 445,734	$ 454,796	$ 425,873	$ 422,823	$ 405,605	$ 454,796	$ 405,605
Net current period other comprehensive income (loss)	23,745	490	(6,323)	(26,917)	(7,100)	10,115	17,912	(23,902)
Balance	500,342	467,667	445,734	408,716	425,873	422,823	500,342	408,716
Hedging Derivative Instruments [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	4,381		3,911	5,476		4,735	3,911	4,735
Other comprehensive income (loss) before reclassifications	(1,851)			385			(1,381)	1,126
Amounts reclassified from accumulated other comprehensive income	0			0			0	0
Net current period other comprehensive income (loss)	(1,851)			385			(1,381)	1,126
Balance	2,530	4,381		5,861	5,476		2,530	5,861
Securities Available-For-Sale and Transferred Securities [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	(118,541)		(111,906)	(126,648)		(128,634)	(111,906)	(128,634)
Other comprehensive income (loss) before reclassifications	25,420			(27,457)			18,765	(25,497)
Amounts reclassified from accumulated other comprehensive income	10			12			30	38
Net current period other comprehensive income (loss)	25,430			(27,445)			18,795	(25,459)
Balance	(93,111)	(118,541)		(154,093)	(126,648)		(93,111)	(154,093)
Pension And Post-Retirement Obligations [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	(11,614)		(11,946)	(13,300)		(13,588)	(11,946)	(13,588)
Other comprehensive income (loss) before reclassifications	0			0			0	0
Amounts reclassified from accumulated other comprehensive income	166			143			498	431
Net current period other comprehensive income (loss)	166			143			498	431
Balance	(11,448)	(11,614)		(13,157)	(13,300)		(11,448)	(13,157)
Accumulated Other Comprehensive (Loss) Income [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Balance	(125,774)	(126,264)	(119,941)	(134,472)	(127,372)	(137,487)	(119,941)	(137,487)
Other comprehensive income (loss) before reclassifications	23,569			(27,072)			17,384	(24,371)
Amounts reclassified from accumulated other comprehensive income	176			155			528	469
Net current period other comprehensive income (loss)	23,745	490	(6,323)	(26,917)	(7,100)	10,115	17,912	(23,902)
Balance	$ (102,029)	$ (125,774)	$ (126,264)	$ (161,389)	$ (134,472)	$ (127,372)	$ (102,029)	$ (161,389)