Benefit Plans (Details Textuals) $ in Thousands	3 Months Ended
	Mar. 31, 2019 USD ($)
Pension Plans, Defined Benefit [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contribution to benefit plan	$ 3,700
Expected contribution to benefit plans for remainder of fiscal year	100
Postretirement Health Coverage [Member]
Defined Benefit Plans and Other Postretirement Benefit Plans Table Text Block [Line Items]
Contribution to benefit plan	165
Expected contribution to benefit plans for remainder of fiscal year	$ 55