Property and Equipment, net (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2020	Mar. 31, 2019	Dec. 31, 2019
Property and equipment, net
Property and equipment, gross	$ 1,170,332		$ 1,080,389
Less accumulated depreciation and amortization	(509,116)		(455,845)
Property and equipment, net	661,216		624,544
Depreciation and amortization	66,400	$ 39,400
Furniture and computer equipment
Property and equipment, net
Property and equipment, gross	533,192		509,120
Site and software development costs
Property and equipment, net
Property and equipment, gross	332,722		297,252
Leasehold improvements
Property and equipment, net
Property and equipment, gross	277,355		228,514
Construction in progress
Property and equipment, net
Property and equipment, gross	$ 27,063		$ 45,503

Amount of accumulated depreciation, depletion and amortization for physical assets used in the normal conduct of business to produce goods and services.

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Amount before accumulated depreciation, depletion and amortization of physical assets used in the normal conduct of business and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.

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