Goodwill and Intangible Assets - Summary Of Amortization Expense (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2019	Mar. 31, 2018
Finite Lived Intangible Assets [Line Items]
Amortization expense, total	$ 240	$ 290
Cost of Revenues [Member]
Finite Lived Intangible Assets [Line Items]
Amortization expense, total	167	166
Operating Expense [Member]
Finite Lived Intangible Assets [Line Items]
Amortization expense, total	$ 73	$ 124