Shares of Common Stock Authorized and Reserved for Future Issuance (Detail)	Dec. 31, 2013
Class of Stock [Line Items]
Total common stock authorized and reserved for future issuance	13,371,980
Option To purchase common stock
Class of Stock [Line Items]
Total common stock authorized and reserved for future issuance	10,828,682
Option available for future issuance
Class of Stock [Line Items]
Total common stock authorized and reserved for future issuance	1,939,123
Series A convertible preferred stock warrant
Class of Stock [Line Items]
Total common stock authorized and reserved for future issuance	408,940
Common stock warrants
Class of Stock [Line Items]
Total common stock authorized and reserved for future issuance	195,235