Segment Reporting (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2013	Mar. 31, 2012
Segment Reporting Information [Line Items]
Total product revenues	$ 148,090	$ 129,526
Total product revenues in percentage	100.00%	100.00%
United States
Segment Reporting Information [Line Items]
Total product revenues	63,312	55,711
Total product revenues in percentage	43.00%	43.00%
Germany
Segment Reporting Information [Line Items]
Total product revenues	19,985	17,941
Total product revenues in percentage	13.00%	14.00%
China
Segment Reporting Information [Line Items]
Total product revenues	14,129	11,176
Total product revenues in percentage	10.00%	9.00%
South Korea
Segment Reporting Information [Line Items]
Total product revenues	11,488	7,945
Total product revenues in percentage	8.00%	6.00%
Japan
Segment Reporting Information [Line Items]
Total product revenues	9,007	6,039
Total product revenues in percentage	6.00%	5.00%
United Kingdom
Segment Reporting Information [Line Items]
Total product revenues	4,131	3,683
Total product revenues in percentage	3.00%	3.00%
Czech Republic
Segment Reporting Information [Line Items]
Total product revenues	3,658	4,592
Total product revenues in percentage	2.00%	3.00%
Canada
Segment Reporting Information [Line Items]
Total product revenues	3,518	4,156
Total product revenues in percentage	2.00%	3.00%
Mexico
Segment Reporting Information [Line Items]
Total product revenues	3,441	4,436
Total product revenues in percentage	2.00%	3.00%
Other
Segment Reporting Information [Line Items]
Total product revenues	$ 15,421	$ 13,847
Total product revenues in percentage	11.00%	11.00%