Property and Equipment

9 Months Ended

12 Months Ended

Sep. 30, 2020

Dec. 31, 2019

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 September 30, 2020 and December 31, 2019 consisted of the following:

	Estimated Useful Life		September 30, 2020			December 31, 2019
Lab and test equipment		7 years	$	17,755		$	14,810
Vehicles		5 years		12,869			11,073
Equipment		3–7 years		31,539			29,922
Furniture and fixtures		7 years		2,854			1,119
Leasehold improvements		7 years		6,758			5,954
Aircraft		10 years		834			—
Building		39 years		2,975			—
				75,584			62,878
Land				725			—
Construction in progress				156			796
Less accumulated depreciation				(41,906	)		(36,638	)
Total property and equipment—net			$	34,559		$	27,036

Total depreciation expense included on the condensed consolidated statements of operations was $2.1 million and $6.1 million for the three and nine months ended September 30, 2020, respectively. Total depreciation expense included on the condensed consolidated statements of operations was $2.1 million and $5.9 million for the three and nine months ended September 30, 2019, respectively.

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 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 December 31, 2019 and 2018 consisted of the following:

	Estimated Useful Life		2019			2018
Lab and test equipment		7 years	$	14,810		$	10,275
Vehicles		5 years		11,073			8,122
Equipment		3-7 years		29,922			25,468
Furniture and fixtures		7 years		1,119			1,004
Leasehold improvements		7 years		5,954			5,137
				62,878			50,006
Construction in progress				796
Less accumulated depreciation and amortization				(36,638	)		(29,214	)
Total property and equipment—net			$	27,036		$	20,792

Total depreciation expense included on the consolidated statements of operations was $7.7 million and $7.6 million for the years ended December 31, 2019 and 2018, respectively.