Segment Customer and Geographic Information - Additional Information (Detail) (Government Grants And Cooperative Agreements)	12 Months Ended
Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2010
Government Grants And Cooperative Agreements
Revenue, Major Customer [Line Items]
Company's total product revenue from significant customers	1.00%	7.00%	6.00%

Percentage of revenue generated from a single external customer that accounts for 10 percent or more of an entity's revenues.

No definition available.

Name:	us-gaap_EntityWideRevenueMajorCustomerPercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration