Common Stock Reserved for Issuance (Detail)	12 Months Ended
Common Stock Reserved for Issuance (Detail)	Dec. 31, 2013
Components of Common Stock Reserved [Line Items]
Employee stock options and restricted stock	1,175,020
Base Warrant
Components of Common Stock Reserved [Line Items]
Common Stock Reserved for Issuance	289,187
Series B Preferred Stock
Components of Common Stock Reserved [Line Items]
Common Stock Reserved for Issuance	153
Series C Preferred Stock
Components of Common Stock Reserved [Line Items]
Common Stock Reserved for Issuance	14,515,894
Series C Preferred Stock \| Other Accrued Liabilities
Components of Common Stock Reserved [Line Items]
Common Stock Reserved for Issuance	1,013,889
Series E Preferred Stock
Components of Common Stock Reserved [Line Items]
Common Stock Reserved for Issuance	4,273,504
Series F Preferred Stock
Components of Common Stock Reserved [Line Items]
Common Stock Reserved for Issuance	1,089,775