Royalty Agreement - Additional Information (Detail) (USD $) In Millions, unless otherwise specified	12 Months Ended	1 Months Ended
	Dec. 31, 2013	Sep. 30, 2012 Royalty Agreement [Member]	Sep. 30, 2012 Royalty Agreement Terms [Member]
Royalty Agreement [Line Items]
Acquisition price of revenue participation right			$ 25.0
Fair value of warrants issued in connection with royalty agreement		$ 3.1
Revenue participation right payment, rate	6.75%
Revenue participation right payment, term	10 years from the date of first commercial sale
Maximum term of revenue participation right payments	10 years