Acquisitions - Additional Information (Detail) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2013	Mar. 31, 2013	Jun. 30, 2013
Business Acquisition [Line Items]
License fees received			$ 3,000,000
Transaction costs expensed	$ 0	$ 15,000
In-process research and development [Member]
Business Acquisition [Line Items]
Estimated cash flow period			10 years
Estimated cash flow discount rate	25.00%		25.00%