Segment Reporting (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
Product revenues	$ 856,445	$ 811,300	$ 662,082
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	$ 393,206	$ 361,706	$ 292,079
United States | Sales Revenue, Net | Geographic Concentration Risk
Segment Reporting Information [Line Items]
Total product revenues in percentage	46.00%	45.00%	44.00%
South Korea
Segment Reporting Information [Line Items]
Product revenues	$ 84,758	$ 89,515	$ 58,329
South Korea | Sales Revenue, Net | Geographic Concentration Risk
Segment Reporting Information [Line Items]
Total product revenues in percentage	10.00%	11.00%	9.00%
China
Segment Reporting Information [Line Items]
Product revenues	$ 76,864	$ 69,910	$ 70,671
China | Sales Revenue, Net | Geographic Concentration Risk
Segment Reporting Information [Line Items]
Total product revenues in percentage	9.00%	9.00%	11.00%
Germany
Segment Reporting Information [Line Items]
Product revenues	$ 74,003	$ 90,243	$ 84,035
Germany | Sales Revenue, Net | Geographic Concentration Risk
Segment Reporting Information [Line Items]
Total product revenues in percentage	9.00%	11.00%	13.00%
Japan
Segment Reporting Information [Line Items]
Product revenues	$ 46,058	$ 47,528	$ 39,844
Japan | Sales Revenue, Net | Geographic Concentration Risk
Segment Reporting Information [Line Items]
Total product revenues in percentage	5.00%	6.00%	6.00%
Mexico
Segment Reporting Information [Line Items]
Product revenues	$ 28,274	$ 19,590	$ 15,670
Mexico | Sales Revenue, Net | Geographic Concentration Risk
Segment Reporting Information [Line Items]
Total product revenues in percentage	3.00%	2.00%	2.00%
Czech Republic
Segment Reporting Information [Line Items]
Product revenues	$ 28,273	$ 25,738	$ 17,247
Czech Republic | Sales Revenue, Net | Geographic Concentration Risk
Segment Reporting Information [Line Items]
Total product revenues in percentage	3.00%	3.00%	3.00%
Canada
Segment Reporting Information [Line Items]
Product revenues	$ 27,076	$ 20,293	$ 14,254
Canada | Sales Revenue, Net | Geographic Concentration Risk
Segment Reporting Information [Line Items]
Total product revenues in percentage	3.00%	2.00%	2.00%
United Kingdom
Segment Reporting Information [Line Items]
Product revenues	$ 25,952	$ 24,712	$ 18,864
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	$ 71,981	$ 62,065	$ 51,089
Other | Sales Revenue, Net | Geographic Concentration Risk
Segment Reporting Information [Line Items]
Total product revenues in percentage	9.00%	8.00%	7.00%
Non U.S.
Segment Reporting Information [Line Items]
Product revenues	$ 463,239	$ 449,594	$ 370,003
Non U.S. | Sales Revenue, Net | Geographic Concentration Risk
Segment Reporting Information [Line Items]
Total product revenues in percentage	54.00%	56.00%	56.00%