Collaboration and License Agreements - Additional Information (Detail) (USD $)	3 Months Ended		9 Months Ended
	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Jun. 30, 1998
Collaborations And License Agreements [Line Items]
Percentage of royalty received on net sales			2.00%
License agreement date			Jun. 30, 1998
Monthly license fees					$ 2,000
Potential future development payments					800,000
Development payment	0	0	0	0
Royalty payment	0	0	0	0
Ortho-McNeil Inc. [Member]
Collaborations And License Agreements [Line Items]
Entered into a collaboration agreement			Aug. 31, 2006
Payments made under agreement	0	0	0	0
Royalties received	0	0	0	0
Ortho-McNeil Inc. [Member] \| Maximum [Member]
Collaborations And License Agreements [Line Items]
Percentage of royalty received on net sales			8.00%
Janssen Pharmaceuticals, Inc. [Member]
Collaborations And License Agreements [Line Items]
License agreement date			Jun. 30, 2010
Number of development and license agreements			2
Contingent payment eligible to receive on development and commercial events	$ 228,000,000		$ 228,000,000