Quarterly report pursuant to Section 13 or 15(d)

Net Loss Per Share - Additional Information (Detail)

v3.8.0.1
Net Loss Per Share - Additional Information (Detail) - shares
shares in Millions
9 Months Ended
Sep. 30, 2017
Sep. 30, 2016
Stock Compensation Plan [Member]    
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]    
Antidilutive securities excluded from computation of earnings per share amount 0.7 7.4