Stockholders' Equity (Accumulated Other Comprehensive (Loss) 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 (Loss) Income [Roll Forward]
Unrealized Loss on Securities			$ (2,088)
Realized gain on sale of securities, net of tax			115
Amounts reclassified out of accumulated other comprehensive loss per ASU 2016-01 (a)	$ 0	$ 0	(5,020)	$ 0
Other comprehensive (loss) income, net of reclassifications and tax			(13,629)
Unrealized Loss on Securities	(20,622)		(20,622)
Unrecognized Net Pension and Postretirement Costs			(4,256)
Other Comprehensive Income (Loss), Defined Benefit Plan, Settlement and Curtailment Gain (Loss), after Tax			139
Other comprehensive (loss) income, net of reclassifications and tax			993
Unrecognized Net Pension and Postretirement Costs	(3,124)		(3,124)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax			1,129
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	514	$ (41)	2,027	$ (541)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	3,156		3,156
Accumulated Other Comprehensive Loss			(5,215)
Other Comprehensive Income (Loss), Reclassification Adjustment in Net Income, Net of Tax			115
Other Comprehensive Income (Loss), Settlement and Curtailment Costs of Pension and Other Postretirement Benefit Plan Valuation, Net of Tax			139
Other comprehensive (loss) income, net of reclassifications and tax			(10,609)
Accumulated Other Comprehensive Loss	$ (20,590)		$ (20,590)