Intangible Assets - Additional Information (Detail) $ in Thousands	9 Months Ended
Sep. 30, 2015 USD ($) Candidate
Finite Lived Intangible Assets [Line Items]
Impairment charge \| $	$ 1,870
Ceregene, Inc. [Member]
Finite Lived Intangible Assets [Line Items]
Number of clinical product candidates	2

Amount of impairment loss resulting from write-down of assets, excluding financial assets and goodwill, lacking physical substance and having a projected indefinite period of benefit to fair value.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 350

-SubTopic 30

-Section 50

-Paragraph 3

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=26713463&loc=d3e16373-109275

Name:	us-gaap_ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration