Summary of Significant Accounting Policies - Equity at the Market Offering, Income Taxes, Inventory and Property and Equipment (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended		3 Months Ended	9 Months Ended
	Apr. 30, 2021	Jun. 30, 2020	Sep. 30, 2021	Sep. 30, 2021	Sep. 30, 2020
Class of Stock [Line Items]
Shares sold under at-the-market offering program			$ 2,504
Income tax cash refunds	$ 3,700	$ 2,700
CARES Act, cash benefits for the fiscal year 2020			6,800	$ 6,800
Inventory write-down					$ 24,200
Common Stock
Class of Stock [Line Items]
Shares sold under at-the-market offering program			8
Minimum
Property, Plant and Equipment [Abstract]
Property and equipment, useful life				2 years
Maximum
Property, Plant and Equipment [Abstract]
Property and equipment, useful life				39 years
At the Market Offerings | Common Stock
Class of Stock [Line Items]
Shares sold under at-the-market offering program			2,500	$ 2,500
Offering cost			$ 100	$ 100
Shares sold under at-the-market offering program (in shares)			86,323	86,323
Shares sold at the market (in dollars per share)			$ 30.67	$ 30.67