Quarterly report pursuant to Section 13 or 15(d)

Intangible Assets - Additional Information (Detail)

v3.8.0.1
Intangible Assets - Additional Information (Detail) - USD ($)
$ in Millions
3 Months Ended
Mar. 31, 2018
Mar. 31, 2017
Finite-Lived Intangible Assets [Line Items]    
Amortization of intangible assets $ 0.9 $ 1.4