Fair Value of Financial Assets and Liabilities (Schedule of Financial Assets Measured at Fair Value) (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other assets – advance payment to supplier	$ 3,357	$ 3,884
Level 3
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Other assets – advance payment to supplier	$ 3,357	$ 3,884