Property and Equipment

9 Months Ended

Sep. 29, 2018

Property, Plant and Equipment [Abstract]

Property and equipment, net, consists of the following (in thousands):



	September 29, 2018			December 30, 2017
Building and building improvements	$	88,403		$	87,999
Machinery and equipment	53,160			47,556
Aircraft and vehicles	25,554			25,329
Land	23,762			23,762
Computer equipment	16,426			15,789
Leasehold improvements	16,323			15,326
Tooling	14,124			13,754
Furniture and office equipment	10,371			9,967
Demonstration units	471			486
Construction-in-progress (CIP)	9,698			6,365
Total property and equipment	258,292			246,333
Accumulated depreciation and amortization	(93,687		)	(82,237		)
Property and equipment, net	$	164,605		$	164,096

For the three months ended September 29, 2018 and September 30, 2017, depreciation expense of property and equipment was $4.0 million and $3.8 million, respectively. For the nine months ended September 29, 2018 and September 30, 2017, depreciation expense of property and equipment was $12.1 million and $10.8 million, respectively.

The balances in CIP at September 29, 2018 and December 30, 2017 related primarily to capitalized costs associated with the implementation of a new enterprise resource planning software system and manufacturing equipment, the underlying assets for which have not been completed or placed into service.