Derivatives and Fair Value Measurement (Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis) (Details) - Fair Value, Measurements, Recurring [Member] $ in Thousands	Dec. 31, 2020 USD ($)
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets/(Liabilities) Total	$ (2,898)
Forward Commodity Contract [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities	(2,898)
Fair Value, Inputs, Level 1 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets/(Liabilities) Total	0
Fair Value, Inputs, Level 1 [Member] | Forward Commodity Contract [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities	0
Fair Value, Inputs, Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets/(Liabilities) Total	(2,898)
Fair Value, Inputs, Level 2 [Member] | Forward Commodity Contract [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities	(2,898)
Fair Value, Inputs, Level 3 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Assets/(Liabilities) Total	0
Fair Value, Inputs, Level 3 [Member] | Forward Commodity Contract [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Liabilities	$ 0