Other Comprehensive Income (Loss) (Components of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Accumulated other comprehensive income (loss), beginning balance	$ (462)	$ (11,866)	$ (11,237)	$ (28,309)
Other comprehensive income (loss) before reclassifications	(3,612)	2,669	5,972	18,614
Amounts reclassed from accumulated other comprehensive income (loss)	671	273	1,862	771
Total other comprehensive income (loss), net of tax	(2,941)	2,942	7,834	19,385
Accumulated other comprehensive income (loss), ending balance	(3,403)	(8,924)	(3,403)	(8,924)
Net Unrealized Gains (Losses) on AFS Securities [Member]
Accumulated other comprehensive income (loss), beginning balance	14,224	292	3,226	(16,762)
Other comprehensive income (loss) before reclassifications	(3,505)	2,886	7,493	19,879
Amounts reclassed from accumulated other comprehensive income (loss)	0	0	0	61
Total other comprehensive income (loss), net of tax	(3,505)	2,886	7,493	19,940
Accumulated other comprehensive income (loss), ending balance	10,719	3,178	10,719	3,178
Net Unrealized Losses on Cash Flow Hedges [Member]
Accumulated other comprehensive income (loss), beginning balance	(1,835)	(873)	(793)	191
Other comprehensive income (loss) before reclassifications	(107)	(217)	(1,521)	(1,265)
Amounts reclassed from accumulated other comprehensive income (loss)	261	46	633	30
Total other comprehensive income (loss), net of tax	154	(171)	(888)	(1,235)
Accumulated other comprehensive income (loss), ending balance	(1,681)	(1,044)	(1,681)	(1,044)
Pension Benefit Adjustment [Member]
Accumulated other comprehensive income (loss), beginning balance	(12,851)	(11,285)	(13,670)	(11,738)
Other comprehensive income (loss) before reclassifications	0	0	0	0
Amounts reclassed from accumulated other comprehensive income (loss)	410	227	1,229	680
Total other comprehensive income (loss), net of tax	410	227	1,229	680
Accumulated other comprehensive income (loss), ending balance	$ (12,441)	$ (11,058)	$ (12,441)	$ (11,058)