Comprehensive Income/Loss (Comprised of the following Components) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			$ 40,695	$ 18,169
Net change in other comprehensive income (loss)	$ (11,000)	$ (3,213)	(22,128)	30,463
Ending Balance	18,567	48,632	18,567	48,632
Unrealized Gain (Loss) on Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			13,255	4,398
Net change in other comprehensive income (loss)			(11,878)	10,333
Ending Balance	1,377	14,731	1,377	14,731
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			33,276	16,479
Net change in other comprehensive income (loss)			(11,559)	20,452
Ending Balance	21,717	36,931	21,717	36,931
Defined Benefit Postretirement Plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance			(5,836)	(2,708)
Net change in other comprehensive income (loss)			1,309	(322)
Ending Balance	(4,527)	(3,030)	(4,527)	(3,030)
AOCI Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net change in other comprehensive income (loss)	$ (11,000)	$ (3,213)	$ (22,128)	$ 30,463