Property and Equipment, net (Tables)

12 Months Ended

Dec. 31, 2018

Property, Plant and Equipment [Abstract]

Schedule of property and equipment, net

The following table summarizes property and equipment, net as of December 31, 2018 and 2017 (in thousands):

	December 31,
	2018			2017
Furniture and computer equipment	$	339,761		$	213,790
Site and software development costs	172,653			118,356
Leasehold improvements	109,929			82,614
Construction in progress	90,104			46,826
Building (leased - see Note 7)	184,694			83,681
	897,141			545,267
Less accumulated depreciation and amortization	(290,164		)	(184,126		)
Property and equipment, net	$	606,977		$	361,141