Collaborations and Alliances - Additional Information (Detail) (USD $) In Millions, unless otherwise specified		12 Months Ended
Mar. 07, 2011	Dec. 31, 2012 Solasia	Dec. 31, 2012 Solasia Development-based milestones	Dec. 31, 2012 Solasia Sales-based milestones
Schedule Of Research And Development [Line Items]
Upfront payment received		$ 5
Expected Additional milestone payments to be received			$ 32.5	$ 53.5
Upfront payment for research and development funding earning period	75 months

Cash received from licensees for license fees during the current period.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 25

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3536-108585

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 27

-Subparagraph a

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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