Goodwill and Intangible Assets - Additional Information (Detail) - USD ($) $ in Thousands	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 expense of finite life intangible assets	$ 2,300	$ 2,900	$ 7,355	$ 8,666
Amortization expense of finite life intangibles for 2018	2,300		2,300
Amortization expense of finite life intangibles for 2019	8,100		8,100
Amortization expense of finite life intangibles for 2020	6,500		6,500
Amortization expense of finite life intangibles for 2021	5,400		5,400
Amortization expense of finite life intangibles for 2022	$ 4,500		$ 4,500