Components of Net Periodic Benefit Cost (Details Textual) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Defined Benefits Plan Estimated Future Employer Contributions In Next Fiscal Year			$ 1,800
Defined Benefit Plan, Expected Future Benefit Payment, Remainder of Fiscal Year			814
Defined Contribution Plan Employer Accrued Discretionary Contribution Amount	$ 1,063	$ 1,300
Post Retirement Health Benefits [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefits Plan Estimated Future Employer Contributions In Next Fiscal Year			$ 233
Defined Benefit Plan, Plan Assets, Contributions by Employer	188
Pension Plan [Member]
Defined Benefit Plan Disclosure [Line Items]
Defined Benefit Plan, Plan Assets, Contributions by Employer	$ 1,767