Commitments - Additional Information (Detail) - Eli Lilly [Member] - USD ($)			9 Months Ended
	Oct. 23, 2013	Feb. 10, 2005	Sep. 30, 2015
Research and Development Arrangement, Contract to Perform for Others [Line Items]
License agreement date		Dec. 16, 2005
Upfront license fee			$ 1,000,000
Upfront payment received	$ 1,500,000
Aggregate potential milestone payments receivable	$ 3,500,000
Percentage of payment received upon manufacturing cost per tablet	5.00%
Agreement expiration period			15 years
US Food and Drug Administration or European Medicines Agency [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Potential milestone payment receivable upon submission of drug	$ 1,000,000
Potential milestone payment receivable upon approval of drug	1,500,000
Republic of Korea [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Potential milestone payment receivable upon approval of drug	$ 1,000,000
Minimum [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Royalty percentage obligated for payment			8.00%
Percentage of purchase price per unit on net sales	31.50%
Maximum [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
Percentage of purchase price per unit on net sales	36.50%
First Indication [Member] | Maximum [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
License agreement fee			$ 32,000,000
Royalty percentage obligated for payment			11.00%
Subsequent Indication [Member] | Maximum [Member]
Research and Development Arrangement, Contract to Perform for Others [Line Items]
License agreement fee			$ 3,000,000