Acquisition of Assets - Additional Information (Detail) (USD $)	0 Months Ended	9 Months Ended
	Jul. 15, 2014	Sep. 30, 2014	May 22, 2014	Dec. 31, 2013
Asset Acquisition [Line Items]
Purchase and sales agreement date		May 22, 2014
Aggregate purchase price, including certain fees and taxes			$ 15,100,000
Purchase price, paid at closing	10,100,000
Purchase agreement closing date		Jul. 15, 2014
Current portion of notes payable		2,415,000		0
Notes payable		2,262,000		0
July 15, 2015 and January 15, 2016 [Member]
Asset Acquisition [Line Items]
Purchase price, remaining amount		5,000,000
Eisai, Inc. [Member]
Asset Acquisition [Line Items]
Property and equipment		14,800,000
Current portion of notes payable		2,400,000
Notes payable		$ 2,300,000