Other Comprehensive Income (Loss) (Components of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022
Accumulated other comprehensive income (loss), beginning balance			$ (157,800)
Net other comprehensive income (loss)	$ (29,907)	$ (53,714)	(20,934)	$ (151,774)
Accumulated other comprehensive income (loss), ending balance	(178,734)		(178,734)
Net Unrealized Gains (Losses) on AFS Securities [Member]
Accumulated other comprehensive income (loss), beginning balance	(127,662)	(92,197)	(131,033)	(6,795)
Other comprehensive income (loss) before reclassifications	(32,785)	(47,067)	(29,414)	(132,469)
Amounts reclassed from accumulated other comprehensive income (loss)	0	0	0	0
Net other comprehensive income (loss)	(32,785)	(47,067)	(29,414)	(132,469)
Accumulated other comprehensive income (loss), ending balance	(160,447)	(139,264)	(160,447)	(139,264)
Net Unrealized Losses on Cash Flow Hedges [Member]
Accumulated other comprehensive income (loss), beginning balance	(17,133)	(17,321)	(22,645)	(4,013)
Other comprehensive income (loss) before reclassifications	1,669	(7,790)	3,753	(20,820)
Amounts reclassed from accumulated other comprehensive income (loss)	1,164	817	4,592	539
Net other comprehensive income (loss)	2,833	(6,973)	8,345	(20,281)
Accumulated other comprehensive income (loss), ending balance	(14,300)	(24,294)	(14,300)	(24,294)
Pension Benefit Adjustment [Member]
Accumulated other comprehensive income (loss), beginning balance	(4,032)	(8,523)	(4,122)	(9,173)
Other comprehensive income (loss) before reclassifications	0	0	0	0
Amounts reclassed from accumulated other comprehensive income (loss)	45	326	135	976
Net other comprehensive income (loss)	45	326	135	976
Accumulated other comprehensive income (loss), ending balance	(3,987)	(8,197)	(3,987)	(8,197)
Accumulated Other Comprehensive Income (Loss) [Member]
Accumulated other comprehensive income (loss), beginning balance	(148,827)	(118,041)	(157,800)	(19,981)
Other comprehensive income (loss) before reclassifications	(31,116)	(54,857)	(25,661)	(153,289)
Amounts reclassed from accumulated other comprehensive income (loss)	1,209	1,143	4,727	1,515
Net other comprehensive income (loss)	(29,907)	(53,714)	(20,934)	(151,774)
Accumulated other comprehensive income (loss), ending balance	$ (178,734)	$ (171,755)	$ (178,734)	$ (171,755)