Property and Equipment - Summary of Property and Equipment (Details) - USD ($) $ in Thousands	5 Months Ended	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2019	Jan. 01, 2019	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 264,948	$ 264,948
Property and equipment, gross				$ 205,619
Less: Accumulated depreciation and amortization	120,084	120,084
Less: Accumulated depreciation and amortization				85,440
Property and equipment, net	144,864	144,864
Property and equipment, net				120,179
Derecognized existing facility financing obligation	0	0		(59,991)
Property and equipment, net	$ 59,696	$ 59,696
Computer equipment
Property, Plant and Equipment [Line Items]
Estimated useful lives		3 years
Lessee, finance lease, term of contract	3 years	3 years
Property and equipment, gross	$ 35,190	$ 35,190
Property and equipment, gross				36,670
Property and equipment, net	30,400	30,400
Furniture and equipment
Property, Plant and Equipment [Line Items]
Property and equipment, gross	7,999	$ 7,999
Property and equipment, gross				6,574
Furniture and equipment | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives		2 years
Furniture and equipment | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives		4 years
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, gross	48,688	$ 48,688
Property and equipment, gross				10,731
Construction in progress
Property, Plant and Equipment [Line Items]
Property and equipment, gross	$ 206	$ 206
Property and equipment, gross				551
Building
Property, Plant and Equipment [Line Items]
Lessee, finance lease, term of contract	25 years	25 years
Property and equipment, gross	$ 66,650	$ 66,650
Property and equipment, gross				81,892
Website development and internal-use software
Property, Plant and Equipment [Line Items]
Property and equipment, gross	106,215	106,215
Property and equipment, gross	106,215	106,215		69,201	$ 48,333
Less: Accumulated depreciation and amortization	56,815	56,815		38,418	$ 29,991
Property and equipment, net	$ 49,400	$ 49,400		$ 30,783
Website development and internal-use software | Minimum
Property, Plant and Equipment [Line Items]
Estimated useful lives		3 years
Website development and internal-use software | Maximum
Property, Plant and Equipment [Line Items]
Estimated useful lives		5 years
Accounting Standards Update 2016-02
Property, Plant and Equipment [Line Items]
Property and equipment, net			$ (51,100)
Derecognized existing facility financing obligation			60,000
Property and equipment, net			66,700
Accounting Standards Update 2016-02 | Leasehold improvements
Property, Plant and Equipment [Line Items]
Property and equipment, net			22,100
Accounting Standards Update 2016-02 | Building
Property, Plant and Equipment [Line Items]
Property and equipment, net			$ (22,100)
Reverb Holdings Inc. | Website development and internal-use software
Property, Plant and Equipment [Line Items]
Estimated useful lives	3 years
Property and equipment, gross	$ 30,300	$ 30,300
Less: Accumulated depreciation and amortization	$ 3,800	$ 3,800
Acquired intangible asset, useful life	3 years