Acquisitions - 2018 Acquisitions Asset Allocation (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Aug. 31, 2018	Apr. 30, 2018	Dec. 31, 2017	Dec. 31, 2016
Business Acquisition [Line Items]
Cash			$ 18,012
Funds and accounts receivable			1,068
Creator advances			532
Prepaid expenses and other current assets			181
Property and equipment			42
Other noncurrent assets			28
Accounts payable, creators			(19,671)
Other current liabilities			(650)
Intangible assets			3,601
Goodwill	$ 170,560	$ 170,560	11,156		$ 158,766	$ 9,725
Total purchase price			14,299
Picatic
Business Acquisition [Line Items]
Cash			160
Funds and accounts receivable			10
Creator advances			0
Prepaid expenses and other current assets			87
Property and equipment			0
Other noncurrent assets			0
Accounts payable, creators			0
Other current liabilities			(121)
Intangible assets			507
Goodwill			2,219
Total purchase price			$ 2,862
Ticketea
Business Acquisition [Line Items]
Cash				$ 17,852
Funds and accounts receivable				1,058
Creator advances				532
Prepaid expenses and other current assets				94
Property and equipment				42
Other noncurrent assets				28
Accounts payable, creators				(19,671)
Other current liabilities				(529)
Intangible assets				3,094
Goodwill				8,937
Total purchase price				$ 11,437