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	$ 321	$ 332	$ 980	$ 990
Currency Translation Adjustment	400		400
Estimated intangible asset amortization expense next twelve months	1,300		1,300
Estimated intangible asset amortization expense 2019	1,300		1,300
Estimated intangible asset amortization expense 2020	1,200		1,200
Estimated intangible asset amortization expense 2021	1,200		1,200
Estimated intangible asset amortization expense 2022	1,200		1,200
Estimated intangible asset amortization expense 2023	$ 1,100		$ 1,100