Property and Equipment
 12 Months Ended
Dec. 31, 2014
Property, Plant and Equipment [Abstract]  
Property and Equipment
Property and Equipment
Net property and equipment was made up of the following at December 31, 2014 and 2013 (in thousands):
December 31, 2014
Cost
 
Accumulated
Depreciation
 
Net Book Value
Furniture and equipment
$
39,690

 
$
(13,577
)
 
$
26,113

Computer equipment and software
208,628

 
(107,565
)
 
101,063

Leasehold improvements
96,784

 
(23,078
)
 
73,706

Construction in progress
9,145

 
—

 
9,145

 
$
354,247

 
$
(144,220
)
 
$
210,027

December 31, 2013
Cost
 
Accumulated
Depreciation
 
Net Book Value
Furniture and equipment
$
30,374

 
$
(10,815
)
 
$
19,559

Computer equipment and software
168,463

 
(77,880
)
 
90,583

Leasehold improvements
91,294

 
(15,163
)
 
76,131

Construction in progress
10,734

 
—

 
10,734

 
$
300,865

 
$
(103,858
)
 
$
197,007



Depreciation expense, including property and equipment acquired under capital leases, totaled $63.5 million, $42.2 million, and $20.2 million for the years ended December 31, 2014, 2013, and 2012, respectively. Of the total depreciation expense, $4.0 million, $4.3 million, and $3.5 million was related to the data center operations and allocated to cost of revenue for the years ended December 31, 2014, 2013 and 2012, respectively.