Property and Equipment, Net

12 Months Ended

Dec. 31, 2017

Property, Plant and Equipment [Abstract]

Property and equipment, net, consists of the following as of:



	December 31,
	2017			2016
	(in thousands)
Land and land improvements	$	151,286		$	104,318
Data center equipment	784,290			591,085
Capitalized leased assets	35,974			36,408
Buildings, building improvements, and leasehold improvements	338,763			248,680
Substation equipment	4,247			—
Cloud computing equipment	5,661			5,661
Fiber facilities	8,459			6,344
Computer equipment, furniture and fixtures	30,745			21,007
Vehicles	1,573			1,241
Construction in progress	90,059			97,368
Core network equipment	31,472			23,859
Deferred installation charges	4,436			3,858
Property and equipment, gross	1,486,965			1,139,829
Less: accumulated depreciation and amortization	(353,393		)	(265,570		)
Total property and equipment, net	$	1,133,572		$	874,259

During the years ended December 31, 2017, 2016, and 2015, depreciation and amortization expense was $89.1 million, $66.6 million, and $55.4 million, respectively. Accumulated amortization for the capitalized leased assets totaled $8.3 million and $6.6 million as of December 31, 2017 and December 31, 2016, respectively.

During the years ended December 31, 2017, 2016, and 2015, capitalized interest was $2.9 million, $2.7 million, and $1.4 million, respectively.