Summary of Significant Accounting Policies - Common Stock Equivalents Excluded in Calculation of Diluted Loss Per Share (Detail) (Stock Options [Member])
12 Months Ended
Dec. 31, 2013
Dec. 31, 2012
Stock Options [Member]
   
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Number of anti-dilutive securities excluded from computation of earnings per share 898,982 905,284