Summary of Common Stock Reserved for Future Issuance (Detail)	Mar. 31, 2016 shares
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Common stock reserved for future issuance	2,497,587
Warrant
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Common stock reserved for future issuance	471,878
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	1,480,584
Bluehill AG
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Common stock reserved for future issuance	10,355
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	240,882
ESPP
Share Based Compensation Shares Authorized Under Stock Option Plans Exercise Price Range [Line Items]
Common stock reserved for future issuance	293,888