Revenue - Summary of Revenue Disaggregated by Types and Geography (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Disaggregation Of Revenue [Line Items]
Product, service and distribution rights revenue	$ 14,224	$ 30,167	$ 28,474	$ 50,451
Product
Disaggregation Of Revenue [Line Items]
Product, service and distribution rights revenue	10,615	27,905	22,085	46,779
Service
Disaggregation Of Revenue [Line Items]
Product, service and distribution rights revenue	3,490	2,143	6,151	3,434
Distribution Rights
Disaggregation Of Revenue [Line Items]
Product, service and distribution rights revenue	119	119	238	238
U.S.
Disaggregation Of Revenue [Line Items]
Product, service and distribution rights revenue	7,714	23,608	10,798	24,242
U.S. | Product
Disaggregation Of Revenue [Line Items]
Product, service and distribution rights revenue	5,685	22,288	7,303	22,288
U.S. | Service
Disaggregation Of Revenue [Line Items]
Product, service and distribution rights revenue	2,029	1,320	3,495	1,954
Outside of U.S. ("OUS")
Disaggregation Of Revenue [Line Items]
Product, service and distribution rights revenue	6,510	6,559	17,676	26,209
Outside of U.S. ("OUS") | Product
Disaggregation Of Revenue [Line Items]
Product, service and distribution rights revenue	4,930	5,617	14,782	24,491
Outside of U.S. ("OUS") | Service
Disaggregation Of Revenue [Line Items]
Product, service and distribution rights revenue	1,461	823	2,656	1,480
Outside of U.S. ("OUS") | Distribution Rights
Disaggregation Of Revenue [Line Items]
Product, service and distribution rights revenue	$ 119	$ 119	$ 238	$ 238