General and Administrative Expenses - Schedule of General and Administrative Expenses (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
General And Administrative Expense [Abstract]
Salaries	$ 8,323	$ 8,637	$ 24,365	$ 22,289
Other expenses	2,367	4,261	12,803	10,651
Professional fees	1,407	6,051	9,750	12,716
Loss on disposal of property and equipment	457		885	112
Travel expenses	132	1,448	939	3,330
Credit loss expenses	(21)	(275)	288	520
Total	$ 12,665	$ 20,122	$ 49,030	$ 49,618