Comprehensive Income/Loss (Comprised of the following Components) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			$ 18,169	$ (1,173)
Net change in other comprehensive income (loss)	$ (3,213)	$ 5,246	30,463	27,375
Ending Balance	48,632	26,202	48,632	26,202
Unrealized Gain (Loss) on Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			4,398	(5,947)
Net change in other comprehensive income (loss)			10,333	12,349
Ending Balance	14,731	6,402	14,731	6,402
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			16,479	6,148
Net change in other comprehensive income (loss)			20,452	14,905
Ending Balance	36,931	21,053	36,931	21,053
Defined Benefit Postretirement Plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			(2,708)	(1,374)
Net change in other comprehensive income (loss)			(322)	121
Ending Balance	(3,030)	(1,253)	(3,030)	(1,253)
AOCI Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net change in other comprehensive income (loss)	$ (3,213)	$ 5,246	$ 30,463	$ 27,375