Organization, basis of presentation and summary of significant policies - Additional Information (Detail) - USD ($)	9 Months Ended	12 Months Ended
	Sep. 30, 2021	Dec. 31, 2020
Accounting Policies [Abstract]
Common Stock, par value (in usd per share)	$ 0.001	$ 0.001
Preferred Stock, par value (in usd per share)	$ 0.001
Threshold limit for liquid investments	90 days
Inventory obsolescence reserved	$ 3,353,000	$ 2,254,000
Accounts receivable, after allowance for credit loss	$ 57,600,000
Percent of accounts receivable outstanding for 30 days	96.00%
Change in allowance for doubtful accounts and credit losses	$ 0	$ 0