Benefit Plan Schedule of balances of AOCI (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019
Defined Benefit Plans and Other Postretirement Benefit Plans Disclosures [Abstract]
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), after Tax	$ 152	$ 168
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss) Arising During Period, after Tax	43,723	33,933
Other Comprehensive (Income) Loss, Defined Benefit Plan, after Reclassification Adjustment, before Tax	(43,571)	(33,765)
Deferred Tax Assets, Tax Deferred Expense, Other	9,150	7,091
Defined Benefit Plan, Accumulated Other Comprehensive (Income) Loss, before Tax	$ (34,421)	$ (26,674)