Amount, excluding tax collected from customer, of revenue from satisfaction of performance obligation by transferring promised good or service to customer. Tax collected from customer is tax assessed by governmental authority that is both imposed on and concurrent with specific revenue-producing transaction, including, but not limited to, sales, use, value added and excise.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 4
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130543-203045

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130539-203045

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 606
-SubTopic 10
-Section 50
-Paragraph 5
-URI http://asc.fasb.org/extlink&oid=109196051&loc=SL49130545-203045

Name:	us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

Revenue Recognition - Disaggregated Revenues by Timing of Transfer of Goods or Services (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Disaggregation of Revenue [Line Items]
Disaggregated Revenue	$ 14,177	$ 3,828	$ 24,832	$ 12,743
Product Revenue, net
Disaggregation of Revenue [Line Items]
Disaggregated Revenue	7,176		10,047
Collaboration and License Revenue
Disaggregation of Revenue [Line Items]
Disaggregated Revenue	7,001		14,785
Transferred at a point in time
Disaggregation of Revenue [Line Items]
Disaggregated Revenue	7,176		10,047
Transferred at a point in time \| Product Revenue, net
Disaggregation of Revenue [Line Items]
Disaggregated Revenue	7,176		10,047
Transferred over time
Disaggregation of Revenue [Line Items]
Disaggregated Revenue	7,001		14,785
Transferred over time \| Collaboration and License Revenue
Disaggregation of Revenue [Line Items]
Disaggregated Revenue	$ 7,001		$ 14,785