Debt (Schedule of Equipment Financings) (Details) - Loans Payable - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020	Dec. 30, 2020
Equipment Financing Due March 31 2028
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage	0.0385%
Total debt	$ 3,630
2021 Equipment Financing Due April 30 2021
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage	0.0325%
Total debt	$ 2,559
2020 Equipment Financing Due April 30, 2021
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage		0.0325%
Total debt		$ 3,899
Equipment Financing Due December, 2027
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage			0.0373%
Total debt			$ 3,905
Equipment Financings
Debt Instrument [Line Items]
Total debt	$ 13,993