Property and Equipment, Net - Additional Information (Detail) ft² in Thousands, $ in Thousands	6 Months Ended
	Jun. 30, 2018 USD ($) a ft² Building	Jun. 30, 2017 USD ($)
Property Plant And Equipment Useful Life And Values [Abstract]
Depreciation and amortization expense | $	$ 786	$ 341
Number of acres of land purchased | a	15
Number of buildings | Building	5
Gross area of acquired property | ft²	229