Quarterly report pursuant to Section 13 or 15(d)

Property and Equipment - Additional Information (Detail)

v3.8.0.1
Property and Equipment - Additional Information (Detail) - USD ($)
$ in Millions
9 Months Ended
Sep. 30, 2017
Sep. 30, 2016
Property, Plant and Equipment [Abstract]    
Fully depreciated computer software and hardware and furniture, fixtures and equipment write-off $ 2.9 $ 2.7