Property and Equipment, Net

12 Months Ended

Dec. 31, 2021

Property Plant And Equipment [Abstract]

6. PROPERTY AND EQUIPMENT, NET

Property and equipment are stated at cost or estimated fair value for assets acquired through business combinations. Depreciation and amortization are provided using the straight-line method over the estimated useful lives of the assets. Leasehold improvements are amortized using the straight-line method over the shorter of the remaining lease term, including options that are deemed to be reasonably assured, or the estimated useful life of the improvement.

Property and equipment, net, as of December 31, consisted of the following:

	Estimated Useful Life	2021			2020
Lab and test equipment	7 years	$	18,581		$	18,631
Vehicles	5 years		5,414			13,320
Equipment	3-7 years		35,148			32,177
Furniture and fixtures	7 years		2,844			2,938
Leasehold improvements	7 years		7,268			6,767
Aircraft	10 years		931			834
Building	39 years		2,975			2,975
			73,161			77,642
Land			725			725
Construction in progress			2,342			219
Less accumulated depreciation			(44,707	)		(44,187	)
Total property and equipment—net		$	31,521		$	34,399

Total depreciation expense for property and equipment, net included on the consolidated statements of operations was $6.4 million, $8.4 million and $7.7 million for the years ended December 31, 2021, 2020, and 2019, respectively.

Total property and equipment, net as of December 31, 2020 included $7.2 million related to financed assets, which, following the adoption of ASC 842, are presented as part of finance lease right -of-use asset, net (Note 7) and excluded from property and equipment, net on the face of the consolidated statement of financial position as of December 31, 2021.