Fixed Assets (Schedule of Depreciation and Amortization of Fixed Assets) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Cost of sales	$ 45,388	$ 39,442	$ 35,656
Selling, general and administrative expenses	14,719	12,158	10,608
Total	$ 60,107	$ 51,600	$ 46,264