Property and Equipment - Property and Equipment, Net (Detail) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 77,642	$ 62,878
Less accumulated depreciation and amortization	(44,187)	(36,638)
Total property and equipment—net	$ 34,399	27,036
Lab and test equipment
Property Plant And Equipment [Line Items]
Estimated Useful Life	7 years
Property and equipment, gross	$ 18,631	14,810
Vehicles
Property Plant And Equipment [Line Items]
Estimated Useful Life	5 years
Property and equipment, gross	$ 13,320	11,073
Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 32,177	29,922
Equipment \| Minimum
Property Plant And Equipment [Line Items]
Estimated Useful Life	3 years
Equipment \| Maximum [Member]
Property Plant And Equipment [Line Items]
Estimated Useful Life	7 years
Furniture and fixtures
Property Plant And Equipment [Line Items]
Estimated Useful Life	7 years
Property and equipment, gross	$ 2,938	1,119
Leasehold improvements
Property Plant And Equipment [Line Items]
Estimated Useful Life	7 years
Property and equipment, gross	$ 6,767	5,954
Aircraft
Property Plant And Equipment [Line Items]
Estimated Useful Life	10 years
Property and equipment, gross	$ 834
Building
Property Plant And Equipment [Line Items]
Estimated Useful Life	39 years
Property and equipment, gross	$ 2,975
Land
Property Plant And Equipment [Line Items]
Property and equipment, gross	725
Construction in Progress
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 219	$ 796

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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