Goodwill and Intangible Assets - Additional Information (Details) - USD ($) $ / shares in Units, shares in Millions							1 Months Ended		3 Months Ended			12 Months Ended
	Feb. 19, 2020	Dec. 26, 2019	Oct. 29, 2019	Oct. 28, 2019	Jun. 01, 2019	Sep. 04, 2018	Oct. 31, 2018	Sep. 30, 2018	Dec. 31, 2019	Sep. 30, 2019	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Business Acquisition [Line Items]
Amortization expense relating to intangible assets												$ 66,800,000	$ 100,000
Number of shares exchange												15.9
Impairment loss												$ 5,700,000	0
Amortization of Intangible Assets												66,800,000	100,000
Amortization expense relating to purchased intangible assets												$ 2,100,000	200,000
DBOT
Business Acquisition [Line Items]
Equity Method Investment, Ownership Percentage								90.00%
Finite-lived Intangible Assets Acquired										$ 8,300,000
SolidOpinion, Inc ("SolidOpinion")
Business Acquisition [Line Items]
Total purchase price paid											$ 7,200,000
Cash paid to acquire entity											$ 2,500,000
Number of shares exchange	0.5										4.5
Fintalk
Business Acquisition [Line Items]
Total purchase price paid							$ 6,400,000	$ 7,000,000
Cash paid to acquire entity							1,000,000	1,000,000
Number of shares exchange					2.9
Value of capital stock issued							$ 5,400,000	$ 6,000,000
Impairment loss									$ 5,700,000
Grapevine Logic, Inc. ("Grapevine")
Business Acquisition [Line Items]
Equity Method Investment, Ownership Percentage								65.70%
Cash paid to acquire entity						$ 2,400,000
Tree Technologies
Business Acquisition [Line Items]
Equity Method Investment, Ownership Percentage									51.00%			51.00%
Cash paid to acquire entity		$ 900,000
Website name
Business Acquisition [Line Items]
Amortization expense relating to intangible assets													100,000
Amortization of Intangible Assets													$ 100,000
GTB Tokens
Business Acquisition [Line Items]
Number of shares exchange											8.3
Impairment loss									$ 61,100,000
Quote price of GTB			$ 1.84	$ 17.00					$ 0.23