Other Comprehensive Income (Loss) (Components of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Accumulated other comprehensive income (loss), beginning balance			$ (23,510)	$ (19,757)
Other comprehensive income (loss) before reclassifications			(17,475)	2,620
Amounts reclassed from accumulated other comprehensive income (loss)			1,908	766
Total other comprehensive income (loss), net of tax	$ (4,015)	$ 1,298	(15,567)	3,386
Accumulated other comprehensive income (loss), ending balance	(39,077)	(16,371)	(39,077)	(16,371)
Net Unrealized Gains (Losses) on AFS Securities [Member]
Accumulated other comprehensive income (loss), beginning balance			(7,534)	(6,825)
Other comprehensive income (loss) before reclassifications			(18,057)	3,323
Amounts reclassed from accumulated other comprehensive income (loss)			0	0
Total other comprehensive income (loss), net of tax			(18,057)	3,323
Accumulated other comprehensive income (loss), ending balance	(25,591)	(3,502)	(25,591)	(3,502)
Net Unrealized Losses on Cash Flow Hedges [Member]
Accumulated other comprehensive income (loss), beginning balance			(428)	(300)
Other comprehensive income (loss) before reclassifications			582	(703)
Amounts reclassed from accumulated other comprehensive income (loss)			827	339
Total other comprehensive income (loss), net of tax			1,409	(364)
Accumulated other comprehensive income (loss), ending balance	981	(664)	981	(664)
Pension Benefit Adjustment [Member]
Accumulated other comprehensive income (loss), beginning balance			(15,548)	(12,632)
Other comprehensive income (loss) before reclassifications			0	0
Amounts reclassed from accumulated other comprehensive income (loss)			1,081	427
Total other comprehensive income (loss), net of tax			1,081	427
Accumulated other comprehensive income (loss), ending balance	$ (14,467)	$ (12,205)	$ (14,467)	$ (12,205)