Derivative Instruments (Details 1) - USD ($) $ in Thousands		Dec. 31, 2019	Dec. 31, 2018
Schedule of fair value of outstanding derivative instruments recorded as assets and liability
Asset Derivatives, not designated or not qualifying as hedging instruments		$ 327	$ 1,574
Liability Derivatives, not designated or not qualifying as hedging instruments		1,979	2,348
Energy contracts and options [Member] | Other current assets [Member]
Schedule of fair value of outstanding derivative instruments recorded as assets and liability
Asset Derivatives, not designated or not qualifying as hedging instruments	[1]	324	1,116
Energy contracts and options [Member] | Other Assets [Member]
Schedule of fair value of outstanding derivative instruments recorded as assets and liability
Asset Derivatives, not designated or not qualifying as hedging instruments		3	458
Energy contracts and options [Member] | Other current liabilities [Member]
Schedule of fair value of outstanding derivative instruments recorded as assets and liability
Liability Derivatives, not designated or not qualifying as hedging instruments	[1]	1,909	2,028
Energy contracts and options [Member] | Other Liabilities [Member]
Schedule of fair value of outstanding derivative instruments recorded as assets and liability
Liability Derivatives, not designated or not qualifying as hedging instruments		$ 70	$ 320

[1] The Company classifies derivative assets and liabilities as current based on the cash flows expected to be incurred within the following 12 months.