Comprehensive Income/Loss (Comprised of the following Components) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ (1,337)	$ (2,452)
Net change in other comprehensive income (loss)	698	4,264
Ending Balance	(639)	1,812
Unrealized Gain on Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	173	1,306
Net change in other comprehensive income (loss)	531	4,081
Ending Balance	704	5,387
Unrealized Gain (Loss) on Cash Flow Hedge
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	361	(1,955)
Net change in other comprehensive income (loss)	125	161
Ending Balance	486	(1,794)
Deferred Gain on Hedge Transactions
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	281	427
Net change in other comprehensive income (loss)	(36)	(38)
Ending Balance	245	389
Defined Benefit Postretirement Plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(2,152)	(2,230)
Net change in other comprehensive income (loss)	78	60
Ending Balance	$ (2,074)	$ (2,170)