License Agreements (Additional Information) (Detail) - USD ($)	9 Months Ended
Sep. 30, 2015	Sep. 30, 2014
License And Collaboration Agreements [Line Items]
Payments to Acquire Businesses, Gross	$ 0	$ 2,315,000
M D Anderson Cancer Center [Member]
License And Collaboration Agreements [Line Items]
Annual maintenance fee	200,000
Milestone payment for Phase 3	$ 200,000

The cash outflow associated with the acquisition of business during the period. The cash portion only of the acquisition price.

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Investing Activities

-URI http://asc.fasb.org/extlink&oid=6516133

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 13

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3213-108585

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