Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018
Cash Flows From Operating Activities
Net loss	$ (8,781)	$ (23,283)
Adjustments to reconcile net loss to net cash used in operating activities
Depreciation	170	3,291
(Gain) loss on sale of property and equipment	(599)	47
Termination of management agreements	536
Change in fair value of liability	(176)
Impairment of property and equipment	64	6,345
Stock-based compensation expense	2,301	6,402
Warrant modification expense		139
Extinguishment of note payable	(3,540)	(1,875)
Loss on sale of business unit		127
Amortization of note discount	5,605	919
Change in operating assets and liabilities
Prepaid expenses and other current assets	80	514
Intangible digital assets	12	18
Management agreement termination liability	(45)
Right of use asset	9
Operating lease liability	(6)
Other assets	66	(204)
Accounts payable	352	210
Accrued expenses	(8)	(1,413)
Net cash used in operating activities	(3,960)	(8,763)
Cash Flows From Investing Activities
Proceeds from sale of cybersecurity assets		60
Deposits on property and equipment	(203)
Purchase of property and equipment	(3,646)	(6,994)
Proceeds from sale of property and equipment	535	427
Net cash used in investing activities	(3,314)	(6,507)
Cash Flows From Financing Activities
Proceeds from sale of common stock	525	80
Payment of deferred offering costs	(70)
Proceeds from the issuance of notes payable, net of original issue discount		5,200
Proceeds from sale of stock under equity purchase agreement, net of issuance costs	5,053	1,309
Sale of preferred stock, net of issuance costs	1,990
Repayment of notes payable	(210)	(1,649)
Proceeds from exercise of warrants	120	907
Warrant Buybacks	(14)
Net cash provided by financing activities	7,394	5,847
Net change in cash and cash equivalents	120	(9,423)
Cash and cash equivalents, beginning of year	96	9,519
Cash and cash equivalents, end of year	216	96
Supplemental disclosure of cash flow information
Cash paid for interest	3	14
Cash paid for income tax
Non-cash investing and financing activities
Deemed dividend on warrant modification and beneficial conversion feature of preferred stock	1,005
Deemed dividend on trigger of down round provision		2,514
Cumulative effect adjustment related to ASU adoption	3
Conversion of notes payable into common stock	2,738
Repayment of note payable and interest through the issuance of shares under the equity purchase agreement	354	1,310
Acquisition of miners through common stock	311
Reclassification of NCI to accumulated deficit		22
Reclassification of deferred offering costs	70	160
Conversion of Series C convertible preferred stock into common stock	$ 28