Segment Reporting (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Segment Reporting Information [Line Items]
Total product revenues	$ 171,182	$ 141,058	$ 479,792	$ 406,737
Total product revenues in percentage	100.00%	100.00%	100.00%	100.00%
United States
Segment Reporting Information [Line Items]
Total product revenues	76,543	60,012	211,462	173,233
Total product revenues in percentage	45.00%	42.00%	44.00%	43.00%
Germany
Segment Reporting Information [Line Items]
Total product revenues	20,847	17,773	61,332	49,405
Total product revenues in percentage	12.00%	13.00%	13.00%	12.00%
China
Segment Reporting Information [Line Items]
Total product revenues	18,285	15,694	47,972	43,510
Total product revenues in percentage	11.00%	11.00%	10.00%	11.00%
South Korea
Segment Reporting Information [Line Items]
Total product revenues	13,546	10,716	39,069	31,213
Total product revenues in percentage	8.00%	8.00%	8.00%	8.00%
Japan
Segment Reporting Information [Line Items]
Total product revenues	10,281	10,294	28,591	24,014
Total product revenues in percentage	6.00%	7.00%	6.00%	6.00%
United Kingdom
Segment Reporting Information [Line Items]
Total product revenues	5,180	3,407	13,319	12,959
Total product revenues in percentage	3.00%	2.00%	3.00%	3.00%
Mexico
Segment Reporting Information [Line Items]
Total product revenues	4,230	3,581	11,696	11,467
Total product revenues in percentage	2.00%	3.00%	2.00%	3.00%
Czech Republic
Segment Reporting Information [Line Items]
Total product revenues	4,114	4,375	11,893	12,102
Total product revenues in percentage	2.00%	3.00%	3.00%	3.00%
Canada
Segment Reporting Information [Line Items]
Total product revenues	3,432	2,782	10,533	9,527
Total product revenues in percentage	2.00%	2.00%	2.00%	2.00%
Other
Segment Reporting Information [Line Items]
Total product revenues	$ 14,724	$ 12,424	$ 43,925	$ 39,307
Total product revenues in percentage	9.00%	9.00%	9.00%	10.00%