Equity Plans and Stock-Based Compensation - Stock-Based Compensation Expense (Detail) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Deferred Compensation Arrangement With Individual Share Based Payments [Line Items]
Stock-based compensation expense	$ 5,376	$ 4,102	$ 15,123	$ 9,968
Research and Development
Deferred Compensation Arrangement With Individual Share Based Payments [Line Items]
Stock-based compensation expense	798	778	2,607	(21)
Selling, General and Administrative
Deferred Compensation Arrangement With Individual Share Based Payments [Line Items]
Stock-based compensation expense	3,930	2,504	10,519	7,437
Cost of Sales - Product
Deferred Compensation Arrangement With Individual Share Based Payments [Line Items]
Stock-based compensation expense	124	137	448	452
Inventory
Deferred Compensation Arrangement With Individual Share Based Payments [Line Items]
Stock-based compensation expense	$ 524	$ 683	$ 1,549	$ 2,100

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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