Components of Net Periodic Benefit Cost (Details Textual) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Defined Benefit Plan Disclosure [Line Items]
Defined Benefits Plan Estimated Future Employer Contributions In Next Fiscal Year			$ 2,300
Defined Benefit Plan, Expected Future Benefit Payment, Remainder of Fiscal Year			715
Defined Contribution Plan Employer Accrued Discretionary Contribution Amount	$ 552	$ 412
Post Retirement Health Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefits Plan Estimated Future Employer Contributions In Next Fiscal Year			$ 240
Defined Benefit Plan, Plan Assets, Contributions by Employer	56
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Contributions by Employer	$ 0