Stockholders' Equity (Accumulated Other Comprehensive (Loss) Income) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Accumulated Other Comprehensive (Loss) Income [Roll Forward]
Unrealized Loss on Securities	$ (10,082)
Realized gain on sale of securities, net of tax	(24)
Other comprehensive income (loss), net of reclassifications and tax	6,893
Unrealized Loss on Securities	(3,213)
Unrecognized Net Pension and Postretirement Costs	(3,711)
Other comprehensive income (loss), net of reclassifications and tax	15
Unrecognized Net Pension and Postretirement Costs	(3,696)
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	860
Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax	(1,448)	$ 1,089
Other Comprehensive Income (Loss), Derivatives Qualifying as Hedges, Net of Tax	(588)
Accumulated Other Comprehensive Loss	(12,933)
Other Comprehensive Income (Loss), Reclassification Adjustment in Net Income, Net of Tax	(24)
Other comprehensive income (loss), net of reclassifications and tax	5,460
Accumulated Other Comprehensive Loss	$ (7,497)