Revenue - Product Revenue Allowance and Reserves (Detail) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 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	5,394	1,547
Adjustments related to prior period sales	(172)	(337)
Deductions applied and payments made	(3,931)	(1,909)
Ending balance	3,003	1,542
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	2,932	864
Adjustments related to prior period sales	(50)	(387)
Deductions applied and payments made	(2,229)	(1,185)
Ending balance	1,227	910
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	1,965	247
Adjustments related to prior period sales	(22)
Deductions applied and payments made	(1,121)	(400)
Ending balance	1,357	118
Returns [Member]
Disclosure Of Product Revenue Reserves And Allowances [Line Items]
Beginning balance	603	352
Provision related to sales in the current year	497	436
Adjustments related to prior period sales	(100)	50
Deductions applied and payments made	(581)	(324)
Ending balance	$ 419	$ 514