Revenue - Product Revenue Allowance and Reserves (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Disclosure Of Product Revenue Reserves And Allowances [Line Items]
Beginning balance	$ 1,712	$ 2,241
Provision related to sales in the current year	9,382	2,633
Adjustments related to prior period sales	(272)	(337)
Deductions applied and payments made	(7,739)	(2,822)
Ending balance	3,083	1,715
Chargebacks, Discounts and Fees [Member]
Disclosure Of Product Revenue Reserves And Allowances [Line Items]
Beginning balance	574	1,618
Provision related to sales in the current year	4,990	1,464
Adjustments related to prior period sales	(50)	(387)
Deductions applied and payments made	(4,631)	(1,899)
Ending balance	883	796
Government and Other Rebates [Member]
Disclosure Of Product Revenue Reserves And Allowances [Line Items]
Beginning balance	535	271
Provision related to sales in the current year	3,686	479
Adjustments related to prior period sales	(22)
Deductions applied and payments made	(2,404)	(400)
Ending balance	1,795	350
Returns [Member]
Disclosure Of Product Revenue Reserves And Allowances [Line Items]
Beginning balance	603	352
Provision related to sales in the current year	706	690
Adjustments related to prior period sales	(200)	50
Deductions applied and payments made	(704)	(523)
Ending balance	$ 405	$ 569