Property and Equipment, Net - Property and Equipment, Net (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2021	Dec. 31, 2020
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 80,043	$ 77,642
Less accumulated depreciation	(46,316)	(44,187)
Total property and equipment— net	$ 34,941	34,399
Lab and test equipment
Property Plant And Equipment [Line Items]
Estimated Useful Life	7 years
Property and equipment, gross	$ 19,017	18,631
Vehicles
Property Plant And Equipment [Line Items]
Estimated Useful Life	5 years
Property and equipment, gross	$ 14,047	13,320
Equipment
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 33,263	32,177
Equipment \| Minimum
Property Plant And Equipment [Line Items]
Estimated Useful Life	3 years
Equipment \| Maximum
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	$ 3,023	2,938
Leasehold improvements
Property Plant And Equipment [Line Items]
Estimated Useful Life	7 years
Property and equipment, gross	$ 6,884	6,767
Aircraft
Property Plant And Equipment [Line Items]
Estimated Useful Life	10 years
Property and equipment, gross	$ 834	834
Building
Property Plant And Equipment [Line Items]
Estimated Useful Life	39 years
Property and equipment, gross	$ 2,975	2,975
Land
Property Plant And Equipment [Line Items]
Property and equipment, gross	725	725
Construction in Progress
Property Plant And Equipment [Line Items]
Property and equipment, gross	$ 489	$ 219

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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