Comprehensive Income/Loss (Comprised of the following Components) (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	$ 2,183	$ 40,695
Net change in other comprehensive income (loss)	(80,385)	(13,538)
Ending Balance	(78,202)	27,157
Unrealized Gain (Loss) on Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(9,667)	13,255
Net change in other comprehensive income (loss)	(62,556)	(7,774)
Ending Balance	(72,223)	5,481
Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	14,137	33,276
Net change in other comprehensive income (loss)	(17,950)	(6,583)
Ending Balance	(3,813)	26,693
Defined Benefit Postretirement Plans
Accumulated Other Comprehensive Income (Loss) [Line Items]
Beginning Balance	(2,287)	(5,836)
Net change in other comprehensive income (loss)	121	819
Ending Balance	(2,166)	(5,017)
AOCI Attributable to Parent [Member]
Accumulated Other Comprehensive Income (Loss) [Line Items]
Net change in other comprehensive income (loss)	$ (80,385)	$ (13,538)