Quarterly report pursuant to Section 13 or 15(d)

Amortizable Intangible Assets - Additional Information (Detail)

v3.10.0.1
Amortizable Intangible Assets - Additional Information (Detail) - USD ($)
$ in Millions
3 Months Ended 9 Months Ended
Sep. 30, 2018
Sep. 30, 2017
Sep. 30, 2018
Sep. 30, 2017
Goodwill and Intangible Assets Disclosure [Abstract]        
Amortization of intangible assets $ 1.6 $ 1.1 $ 4.6 $ 3.4