Benefit Plan Schedule of components of net periodic benefit cost and other amounts recognized in OCI (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Defined Benefit Plan [Abstract]
Defined Benefit Plan, Service Cost	$ (5,873,000)	$ (6,547,000)	$ (5,270,000)
Defined Benefit Plan, Interest Cost	(5,491,000)	(5,236,000)	(5,085,000)
Defined Benefit Plan, Expected Return (Loss) on Plan Assets	12,105,000	13,417,000	11,455,000
Defined Benefit Plan, Actuarial Gain (Loss), Immediate Recognition as Component in Net Periodic Benefit (Cost) Credit	(1,882,000)	(1,361,000)	(576,000)
Defined Benefit Plan, Net Periodic Benefit Cost (Credit), Total	1,141,000	(273,000)	(524,000)
Other Comprehensive (Income) Loss, Defined Benefit Plan, Prior Service Cost (Credit), before Tax	1,913,000	(5,122,000)	(11,698,000)
Defined Benefit Plan, Amortization of Gain (Loss)	1,882,000	1,361,000	576,000
Other Comprehensive Income (Loss), Defined Benefit Plan, Gain (Loss), after Reclassification Adjustment, before Tax	3,795,000	(3,761,000)	(11,122,000)
Total Recognized In Net Benefit Cost And Other Comprehensive Loss Income	$ 2,654,000	$ (3,488,000)	$ (10,598,000)