Segment Reporting (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2020	Jun. 30, 2019	Jun. 30, 2020	Jun. 30, 2019
Segment Reporting Information [Line Items]
Product revenues	$ 136,061	$ 243,326	$ 364,674	$ 501,247
Type of Revenue [Extensible List]	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember	us-gaap:ProductMember
United States
Segment Reporting Information [Line Items]
Product revenues	$ 47,097	$ 110,632	$ 153,015	$ 229,086
Germany
Segment Reporting Information [Line Items]
Product revenues	9,761	20,300	26,591	43,510
South Korea
Segment Reporting Information [Line Items]
Product revenues	20,385	15,577	36,802	30,555
Japan
Segment Reporting Information [Line Items]
Product revenues	9,349	20,003	25,486	38,594
China
Segment Reporting Information [Line Items]
Product revenues	23,517	16,410	36,520	32,007
Czech Republic
Segment Reporting Information [Line Items]
Product revenues	5,520	10,009	15,593	22,151
Canada
Segment Reporting Information [Line Items]
Product revenues	3,089	10,102	11,351	20,393
Romania
Segment Reporting Information [Line Items]
Product revenues	2,960	6,009	10,619	12,931
United Kingdom
Segment Reporting Information [Line Items]
Product revenues	1,405	6,833	8,369	15,665
Other
Segment Reporting Information [Line Items]
Product revenues	12,978	27,451	40,328	56,355
Non U.S.
Segment Reporting Information [Line Items]
Product revenues	$ 88,964	$ 132,694	$ 211,659	$ 272,161