Pension and Postretirement Benefits (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Estimated Future Employer Contributions in Current Fiscal Year	$ 8,000
Defined Benefit Plan Effect Of Settlements And Curtailments On Accumulated Benefit Obligation	22,700
Pension Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	1,174	$ 986
Defined Benefit Plan, Interest Cost	1,769	1,111
Defined Benefit Plan, Expected Return on Plan Assets	(1,959)	(984)
Defined Benefit Plan, Settlement Charge	22,667	0
Defined Benefit Plan, Amortization of Losses	1,047	775
Defined Benefit Plan, Amortization of Prior Service Cost	(40)	(42)
Defined Benefit Plan, Net Periodic Benefit Cost	24,658	1,846
Defined Benefit Plan, Contributions by Employer	3,800
Pension Plans, Defined Benefit [Member] | 2019 Year [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Contributions In Current Fiscal Year	10,000
Other Postretirement Benefit Plans, Defined Benefit [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Service Cost	2	2
Defined Benefit Plan, Interest Cost	26	35
Defined Benefit Plan, Expected Return on Plan Assets	0	0
Defined Benefit Plan, Settlement Charge	0	0
Defined Benefit Plan, Amortization of Losses	15	0
Defined Benefit Plan, Amortization of Prior Service Cost	0	0
Defined Benefit Plan, Net Periodic Benefit Cost	43	$ 37
Defined Benefit Plan, Contributions by Employer	100
Other Postretirement Benefit Plans, Defined Benefit [Member] | 2019 Year [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Expected Contributions In Current Fiscal Year	400
Defined Benefit Plan Settlement on Legacy Quaker Plan[Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Contributions by Employer	$ 1,800