Other Comprehensive Income (Loss) (Components of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Accumulated other comprehensive income (loss), beginning balance	$ (28,309)	$ (23,510)
Other comprehensive income (loss) before reclassifications	10,603	(9,702)
Amounts reclassed from accumulated other comprehensive income (loss)	203	537
Total other comprehensive income (loss), net of tax	10,806	(9,165)
Accumulated other comprehensive income (loss), ending balance	(17,503)	(32,675)
Net Unrealized Gains (Losses) on AFS Securities [Member]
Accumulated other comprehensive income (loss), beginning balance	(16,762)	(7,534)
Other comprehensive income (loss) before reclassifications	11,021	(10,414)
Amounts reclassed from accumulated other comprehensive income (loss)	0	0
Total other comprehensive income (loss), net of tax	11,021	(10,414)
Accumulated other comprehensive income (loss), ending balance	(5,741)	(17,948)
Net Unrealized Losses on Cash Flow Hedges [Member]
Accumulated other comprehensive income (loss), beginning balance	191	(428)
Other comprehensive income (loss) before reclassifications	(418)	712
Amounts reclassed from accumulated other comprehensive income (loss)	(24)	177
Total other comprehensive income (loss), net of tax	(442)	889
Accumulated other comprehensive income (loss), ending balance	(251)	461
Pension Benefit Adjustment [Member]
Accumulated other comprehensive income (loss), beginning balance	(11,738)	(15,548)
Other comprehensive income (loss) before reclassifications	0	0
Amounts reclassed from accumulated other comprehensive income (loss)	227	360
Total other comprehensive income (loss), net of tax	227	360
Accumulated other comprehensive income (loss), ending balance	$ (11,511)	$ (15,188)