Segment Reporting (Detail) (USD $) In Thousands, unless otherwise specified	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Segment Reporting Information [Line Items]
Product revenues	$ 811,300	$ 662,082	$ 554,979
Total product revenues in percentage	100.00%	100.00%	100.00%
United States
Segment Reporting Information [Line Items]
Product revenues	361,706	292,079	233,737
Total product revenues in percentage	45.00%	44.00%	42.00%
Germany
Segment Reporting Information [Line Items]
Product revenues	90,243	84,035	67,132
Total product revenues in percentage	11.00%	13.00%	12.00%
Korea
Segment Reporting Information [Line Items]
Product revenues	89,515	58,329	42,878
Total product revenues in percentage	11.00%	9.00%	8.00%
China
Segment Reporting Information [Line Items]
Product revenues	69,910	70,671	55,674
Total product revenues in percentage	9.00%	11.00%	10.00%
Japan
Segment Reporting Information [Line Items]
Product revenues	47,528	39,844	35,279
Total product revenues in percentage	6.00%	6.00%	6.00%
Czech Republic
Segment Reporting Information [Line Items]
Product revenues	25,738	17,247	15,361
Total product revenues in percentage	3.00%	3.00%	3.00%
United Kingdom
Segment Reporting Information [Line Items]
Product revenues	24,712	18,864	13,194
Total product revenues in percentage	3.00%	3.00%	2.00%
Canada
Segment Reporting Information [Line Items]
Product revenues	20,293	14,254	17,582
Total product revenues in percentage	2.00%	2.00%	3.00%
Mexico
Segment Reporting Information [Line Items]
Product revenues	19,590	15,670	14,988
Total product revenues in percentage	2.00%	2.00%	3.00%
Other
Segment Reporting Information [Line Items]
Product revenues	62,065	51,089	59,154
Total product revenues in percentage	8.00%	7.00%	11.00%
Non U.S.
Segment Reporting Information [Line Items]
Product revenues	$ 449,594	$ 370,003	$ 321,242
Total product revenues in percentage	56.00%	56.00%	58.00%