Property and Equipment

6 Months Ended

Jun. 30, 2020

Property Plant And Equipment [Abstract]

Property and Equipment

5. PROPERTY AND EQUIPMENT

Property and equipment are stated at cost or estimated fair value for assets acquired through business combinations. Depreciation and amortization is 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 June 30, 2020 and December 31, 2019 consisted of the following:

	Estimated Useful Life	June 30, 2020			December 31, 2019
Lab and test equipment	7 years	$	17,219		$	14,810
Vehicles	5 years		12,658			11,073
Equipment	3–7 years		30,747			29,922
Furniture and fixtures	7 years		2,798			1,119
Leasehold improvements	7 years		6,633			5,954
Aircraft	10 years		834			—
Building	39 years		2,975			—
			73,864			62,878
Land			725			—
Construction in progress			—			796
Less accumulated depreciation			(39,818	)		(36,638	)
Total property and equipment—net		$	34,771		$	27,036

Total depreciation expense included on the condensed consolidated statements of operations was $2.0 million and 4.0 million for the three and six months ended June 30, 2020, respectively. Total depreciation expense included on the condensed consolidated statements of operations was $1.9 million and $3.8 million for the three and six months ended June 30, 2019, respectively.