Summary of Common Stock Reserved for Future Issuance (Detail)	Sep. 30, 2014	Mar. 13, 2014
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Common stock reserved for future issuance	3,595,891	300,000
Contingent Consideration Classified as Equity
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Common stock reserved for future issuance	372,856
Warrant
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Common stock reserved for future issuance	963,917
Stock Options And Restricted Stock Units
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Common stock reserved for future issuance	1,298,246
Bluehill I D
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Common stock reserved for future issuance	126,142
Employee Stock Purchase Plan
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Common stock reserved for future issuance	293,888
Stock Incentive Plan Twenty Eleven
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Common stock reserved for future issuance	540,842