Segment Reporting (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Product revenues	$ 917,600	$ 856,445	$ 811,300
Sales Revenue, Net | Geographic Concentration Risk
Segment Reporting Information [Line Items]
Total product revenues in percentage	100.00%	100.00%	100.00%
United States
Segment Reporting Information [Line Items]
Product revenues	$ 449,065	$ 393,206	$ 361,706
United States | Sales Revenue, Net | Geographic Concentration Risk
Segment Reporting Information [Line Items]
Total product revenues in percentage	49.00%	46.00%	45.00%
South Korea
Segment Reporting Information [Line Items]
Product revenues	$ 75,396	$ 84,758	$ 89,515
South Korea | Sales Revenue, Net | Geographic Concentration Risk
Segment Reporting Information [Line Items]
Total product revenues in percentage	8.00%	10.00%	11.00%
China
Segment Reporting Information [Line Items]
Product revenues	$ 80,493	$ 76,864	$ 69,910
China | Sales Revenue, Net | Geographic Concentration Risk
Segment Reporting Information [Line Items]
Total product revenues in percentage	9.00%	9.00%	9.00%
Germany
Segment Reporting Information [Line Items]
Product revenues	$ 70,258	$ 74,003	$ 90,243
Germany | Sales Revenue, Net | Geographic Concentration Risk
Segment Reporting Information [Line Items]
Total product revenues in percentage	8.00%	9.00%	11.00%
Japan
Segment Reporting Information [Line Items]
Product revenues	$ 45,103	$ 46,058	$ 47,528
Japan | Sales Revenue, Net | Geographic Concentration Risk
Segment Reporting Information [Line Items]
Total product revenues in percentage	5.00%	5.00%	6.00%
Mexico
Segment Reporting Information [Line Items]
Product revenues	$ 22,767	$ 28,274	$ 19,590
Mexico | Sales Revenue, Net | Geographic Concentration Risk
Segment Reporting Information [Line Items]
Total product revenues in percentage	2.00%	3.00%	2.00%
Czech Republic
Segment Reporting Information [Line Items]
Product revenues	$ 38,164	$ 28,273	$ 25,738
Czech Republic | Sales Revenue, Net | Geographic Concentration Risk
Segment Reporting Information [Line Items]
Total product revenues in percentage	4.00%	3.00%	3.00%
Canada
Segment Reporting Information [Line Items]
Product revenues	$ 37,954	$ 27,076	$ 20,293
Canada | Sales Revenue, Net | Geographic Concentration Risk
Segment Reporting Information [Line Items]
Total product revenues in percentage	4.00%	3.00%	2.00%
United Kingdom
Segment Reporting Information [Line Items]
Product revenues	$ 28,540	$ 25,952	$ 24,712
United Kingdom | Sales Revenue, Net | Geographic Concentration Risk
Segment Reporting Information [Line Items]
Total product revenues in percentage	3.00%	3.00%	3.00%
Other
Segment Reporting Information [Line Items]
Product revenues	$ 69,860	$ 71,981	$ 62,065
Other | Sales Revenue, Net | Geographic Concentration Risk
Segment Reporting Information [Line Items]
Total product revenues in percentage	8.00%	9.00%	8.00%
Non U.S.
Segment Reporting Information [Line Items]
Product revenues	$ 468,535	$ 463,239	$ 449,594
Non U.S. | Sales Revenue, Net | Geographic Concentration Risk
Segment Reporting Information [Line Items]
Total product revenues in percentage	51.00%	54.00%	56.00%