Other Comprehensive Income (Loss) (Components of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Accumulated other comprehensive income (loss), beginning balance			$ (141,153)
Net other comprehensive income (loss)	$ 29,168	$ (29,907)	23,995	$ (20,934)
Accumulated other comprehensive income (loss), ending balance	(117,158)		(117,158)
Net Unrealized Gains (Losses) on AFS Securities
Accumulated other comprehensive income (loss), beginning balance	(126,830)	(127,662)	(116,591)	(131,033)
Other comprehensive income (loss) before reclassifications	30,254	(32,785)	20,015	(29,414)
Amounts reclassed from accumulated other comprehensive income (loss)	0	0	0	0
Net other comprehensive income (loss)	30,254	(32,785)	20,015	(29,414)
Accumulated other comprehensive income (loss), ending balance	(96,576)	(160,447)	(96,576)	(160,447)
Net Unrealized Losses on Cash Flow Hedges
Accumulated other comprehensive income (loss), beginning balance	(10,599)	(17,133)	(15,619)	(22,645)
Other comprehensive income (loss) before reclassifications	(2,358)	1,669	210	3,753
Amounts reclassed from accumulated other comprehensive income (loss)	1,250	1,164	3,702	4,592
Net other comprehensive income (loss)	(1,108)	2,833	3,912	8,345
Accumulated other comprehensive income (loss), ending balance	(11,707)	(14,300)	(11,707)	(14,300)
Net Unrealized Losses on Defined Benefit Plan Obligations
Accumulated other comprehensive income (loss), beginning balance	(8,897)	(4,032)	(8,943)	(4,122)
Other comprehensive income (loss) before reclassifications	0	0	0	0
Amounts reclassed from accumulated other comprehensive income (loss)	22	45	68	135
Net other comprehensive income (loss)	22	45	68	135
Accumulated other comprehensive income (loss), ending balance	(8,875)	(3,987)	(8,875)	(3,987)
Accumulated Other Comprehensive Income (Loss)
Accumulated other comprehensive income (loss), beginning balance	(146,326)	(148,827)	(141,153)	(157,800)
Other comprehensive income (loss) before reclassifications	27,896	(31,116)	20,225	(25,661)
Amounts reclassed from accumulated other comprehensive income (loss)	1,272	1,209	3,770	4,727
Net other comprehensive income (loss)	29,168	(29,907)	23,995	(20,934)
Accumulated other comprehensive income (loss), ending balance	$ (117,158)	$ (178,734)	$ (117,158)	$ (178,734)