Segment Reporting (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Jun. 30, 2012	Jun. 30, 2013	Jun. 30, 2012
Segment Reporting Information [Line Items]
Total product revenues	$ 160,520	$ 136,153	$ 308,610	$ 265,679
Total product revenues in percentage	100.00%	100.00%	100.00%	100.00%
United States
Segment Reporting Information [Line Items]
Total product revenues	71,569	57,510	134,627	113,221
Total product revenues in percentage	45.00%	42.00%	44.00%	43.00%
Germany
Segment Reporting Information [Line Items]
Total product revenues	20,492	15,770	40,365	33,711
Total product revenues in percentage	13.00%	12.00%	13.00%	13.00%
China
Segment Reporting Information [Line Items]
Total product revenues	15,548	14,561	29,600	25,737
Total product revenues in percentage	10.00%	11.00%	10.00%	10.00%
South Korea
Segment Reporting Information [Line Items]
Total product revenues	14,028	12,975	25,487	20,919
Total product revenues in percentage	9.00%	10.00%	8.00%	8.00%
Japan
Segment Reporting Information [Line Items]
Total product revenues	9,299	7,259	18,272	13,298
Total product revenues in percentage	6.00%	5.00%	6.00%	5.00%
Czech Republic
Segment Reporting Information [Line Items]
Total product revenues	4,118	4,103	7,756	8,695
Total product revenues in percentage	3.00%	3.00%	2.00%	3.00%
Mexico
Segment Reporting Information [Line Items]
Total product revenues	4,023	4,249	7,450	8,685
Total product revenues in percentage	2.00%	3.00%	2.00%	3.00%
United Kingdom
Segment Reporting Information [Line Items]
Total product revenues	4,007	2,865	8,131	6,548
Total product revenues in percentage	2.00%	2.00%	3.00%	2.00%
Canada
Segment Reporting Information [Line Items]
Total product revenues	3,582	4,428	7,085	8,584
Total product revenues in percentage	2.00%	3.00%	2.00%	3.00%
Other
Segment Reporting Information [Line Items]
Total product revenues	$ 13,854	$ 12,433	$ 29,837	$ 26,281
Total product revenues in percentage	8.00%	9.00%	10.00%	10.00%