Property, Equipment and Software, Net
 12 Months Ended
Dec. 31, 2015
Property, Plant and Equipment [Abstract]  
Property, Equipment and Software, Net
Property, Equipment and Software, Net
Property, equipment and software, net consisted of the following as of December 31 (in thousands):
 
2014
 
2015
Capitalized internal-use software costs
$
8,271

 
$
14,800

Computer hardware and software
8,620

 
16,028

Furniture and office equipment
156

 
340

Leasehold improvements
186

 
863

Total
17,233

 
32,031

Less: accumulated depreciation
(6,580
)
 
(12,646
)
Property, equipment and software, net
$
10,653

 
$
19,385


Depreciation and amortization expense for the years ended December 31, 2013, 2014 and 2015 was $2.0 million, $3.1 million and $6.1 million, respectively.