Employee Benefit Plans - Summary of Change in Projected Benefit Obligation (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Change in projected benefit obligation:
Projected benefit obligation at the beginning of the year	$ 10,305	$ 9,711
Acquisition	326	0
Service cost	1,735	1,933	$ 1,601
Interest cost	714	645	599
Benefits paid	(1,066)	(1,001)
Actuarial (gain)/loss	(134)	(1,471)
Effect of exchange rate changes	(836)	488
Projected benefit obligation at the end of the year	11,044	10,305	$ 9,711
Unfunded amount–non-current	3,616	3,377
Unfunded amount–current	8	13
Total accrued liability	3,624	3,390
Accumulated benefit obligation	$ 7,239	$ 7,022