Commitments and Contingencies (Schedule of Changes in Warranty Obligations) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Jan. 01, 2018
Movement in Standard Product Warranty Accrual [Roll Forward]
Balance as of beginning of the period	$ 10,556	$ 14,412	$ 44,068
Reclassified to sales returns upon adoption of ASC 606	0	0	(29,147)
Provision for warranty liability made during the period	7,330	7,050	12,783
Settlements made during the period	(8,646)	(10,906)	(13,292)
Balance as of end of the period	9,240	10,556	$ 14,412
Sales returns	$ 66,972	$ 52,612
Difference between Revenue Guidance in Effect before and after Topic 606 | Accounting Standards Update 2014-09
Movement in Standard Product Warranty Accrual [Roll Forward]
Sales returns				$ 29,100