Summary of Significant Accounting Policies - Additinal Information (Details) - USD ($)		3 Months Ended	12 Months Ended
	Dec. 21, 2017	Dec. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018	Oct. 29, 2019	Jan. 01, 2019
Summary Of Significant Accounting Policies [Line Items]
Impairment loss recognized from intangible assets				$ 0
Depreciation		$ 368,000	$ 460,000	368,000
Impaired related asset retirement costs		$ 1,500,000	2,000,000.0	1,500,000
Impairment loss of intangible assets			20,400,000	5,700,000
Impairment loss related to goodwill			9,300,000
Digital currency transaction amount received				$ 61,100,000
Share Price		$ 0.23		$ 0.23
Recorded impairment losses			200,000	$ 3,000,000.0
Impairment losses right of use assets			6,300,000
Impairment of equity method investments			16,650,000	13,068,000
Advertising and marketing costs			$ 200,000	$ 24,394
U. S. statutory income tax rate	34.00%		21.00%	21.00%	35.00%
Operating right of use assets		$ 6,934,000	$ 7,117,000	$ 6,934,000
Lease liabilities			$ 7,189,000
Digital Currency
Summary Of Significant Accounting Policies [Line Items]
Impairment loss of intangible assets		$ 61,100,000
Digital currency transaction amount received				8,300,000
ASU 2016-02 | Cumulative Effect, Period of Adoption, Adjustment
Summary Of Significant Accounting Policies [Line Items]
Operating right of use assets							$ 3,600,000
Lease liabilities							$ 3,700,000
Minimum | Digital Currency
Summary Of Significant Accounting Policies [Line Items]
Share Price						$ 17.00
Maximum | Digital Currency
Summary Of Significant Accounting Policies [Line Items]
Share Price						$ 1.84
Furnitures and office equipment
Summary Of Significant Accounting Policies [Line Items]
Property Plant And Equipment Estimated Useful Live			3 years
Electronic equipment
Summary Of Significant Accounting Policies [Line Items]
Property Plant And Equipment Estimated Useful Live			3 years
Vehicle
Summary Of Significant Accounting Policies [Line Items]
Property Plant And Equipment Estimated Useful Live			3 years
Construction in progress (Fintech Village)
Summary Of Significant Accounting Policies [Line Items]
Depreciation			$ 0
Impairment of assets			$ 3,300,000	$ 2,300,000