Property and Equipment

9 Months Ended

Sep. 30, 2017

Property, Plant and Equipment [Abstract]

Property and Equipment

Property and Equipment:

A summary of property and equipment at December 31, 2016 and September 30, 2017 is as follows:

		December 31,	September 30,
	Useful Lives	2016	2017
	(years)
Leasehold improvements	Shorter of lease term or economic life	$4,911	$15,369
Website and software development costs	1-3	10,114	13,301
Computer and office equipment	3	2,846	2,862
Software	3	1,367	1,235
Furniture	7	2,406	2,862
Construction in progress		10,856	—
		32,500	35,629
Accumulated depreciation and amortization		(13,274)	(14,029)
Property and equipment, net		$19,226	$21,600

Depreciation and amortization expense for property and equipment amounted to $1,475 and $1,665 for the three months ended September 30,2016 and 2017, respectively, and $4,166 and $4,960 for the nine months ended September 30,2016 and 2017, respectively.