Segment Reporting (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Segment Reporting Information [Line Items]
Product revenues	$ 206,012	$ 171,182	$ 606,132	$ 479,792
Total product revenues in percentage	100.00%	100.00%	100.00%	100.00%
United States
Segment Reporting Information [Line Items]
Product revenues	96,680	76,543	270,597	211,462
Total product revenues in percentage	47.00%	45.00%	45.00%	44.00%
Germany
Segment Reporting Information [Line Items]
Product revenues	22,529	20,847	70,491	61,332
Total product revenues in percentage	11.00%	12.00%	12.00%	13.00%
South Korea
Segment Reporting Information [Line Items]
Product revenues	21,339	13,546	67,293	39,069
Total product revenues in percentage	10.00%	8.00%	11.00%	8.00%
China
Segment Reporting Information [Line Items]
Product revenues	17,557	18,285	50,850	47,972
Total product revenues in percentage	9.00%	11.00%	8.00%	10.00%
Japan
Segment Reporting Information [Line Items]
Product revenues	11,970	10,281	34,291	28,591
Total product revenues in percentage	6.00%	6.00%	6.00%	6.00%
Czech Republic
Segment Reporting Information [Line Items]
Product revenues	6,457	4,114	19,398	11,893
Total product revenues in percentage	3.00%	2.00%	3.00%	3.00%
United Kingdom
Segment Reporting Information [Line Items]
Product revenues	5,363	5,180	18,162	13,319
Total product revenues in percentage	3.00%	3.00%	3.00%	3.00%
Mexico
Segment Reporting Information [Line Items]
Product revenues	4,991	4,230	14,752	11,696
Total product revenues in percentage	2.00%	2.00%	2.00%	2.00%
Canada
Segment Reporting Information [Line Items]
Product revenues	4,811	3,432	12,542	10,533
Total product revenues in percentage	2.00%	2.00%	2.00%	2.00%
Other
Segment Reporting Information [Line Items]
Product revenues	14,315	14,724	47,756	43,925
Total product revenues in percentage	7.00%	9.00%	8.00%	9.00%
Non U.S.
Segment Reporting Information [Line Items]
Product revenues	$ 109,332	$ 94,639	$ 335,535	$ 268,330
Total product revenues in percentage	53.00%	55.00%	55.00%	56.00%