Summary of Significant Accounting Policies (Policies)	3 Months Ended
Mar. 31, 2018
Accounting Policies [Abstract]
Principles of Consolidation	Principles of consolidation The unaudited condensed consolidated financial statements include the accounts of MGT and its wholly owned subsidiaries. All intercompany transactions and balances have been eliminated. Non-controlling interest represents the non-controlling equity investment in MGT subsidiaries, plus the minority investors’ share of the net operating results and other components of equity relating to the non-controlling interest.
Reclassification	Reclassification Certain amounts in prior periods have been reclassified to conform to current period presentation. These reclassifications had no effect on the previously reported net loss.
Use of Estimates and Assumptions and Critical Accounting Estimates and Assumptions	Use of estimates and assumptions and critical accounting estimates and assumptions The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities as of the date of the financial statements, and also affect the amounts of revenues and expenses reported for each period. Actual results could differ from those which result from using such estimates. Management utilizes various other estimates, including but not limited to determining the estimated lives of long-lived assets, determining the potential impairment of intangibles, the fair value of warrants issued, the fair value of stock options, the fair value of conversion features, the fair value of the deemed dividend, the recognition of revenue, the valuation allowance for deferred tax assets and other legal claims and contingencies. The results of any changes in accounting estimates are reflected in the financial statements in the period in which the changes become evident. Estimates and assumptions are reviewed periodically and the effects of revisions are reflected in the period that they are determined to be necessary.
Revenue Recognition	Revenue recognition The Company recognizes revenue when it is realized or realizable and earned. The Company considers revenue realized or realizable and earned when there is persuasive evidence of an arrangement, delivery has occurred, the sales price is fixed or determinable and collectability is probable. The Company’s primary revenue stream is related to the mining of digital currencies. The Company derives its revenue by solving “blocks” to be added to the blockchain and providing transaction verification services within the digital currency networks of cryptocurrencies, such as Bitcoin and Ethereum, commonly termed “cryptocurrency mining.” In consideration for these services, the Company receives digital currency (“Coins”). The Coins are recorded as revenue, using the average spot price of Bitcoin on the date of receipt. The Coins are recorded on the balance sheet at their fair value and re–measured at each reporting date. Costs of revenues includes equipment depreciation, rent, and electricity costs. Revaluation gains or losses, as well gains or losses on sale of Coins are also recorded cost of revenue in the unaudited condensed consolidated statements of operations.
Income Taxes	Income taxes The Company accounts for income taxes in accordance with Accounting Standards Codification (“ASC”) 740, “Income Taxes”. ASC 740 requires an asset and liability approach for financial accounting and reporting for income taxes and established for all the entities a minimum threshold for financial statement recognition of the benefit of tax positions, and requires certain expanded disclosures. The provision for income taxes is based upon income or loss after adjustment for those permanent items that are not considered in the determination of taxable income. Deferred income taxes represent the tax effects of differences between the financial reporting and tax basis of the Company’s assets and liabilities at the enacted tax rates in effect for the years in which the differences are expected to reverse. The Company evaluates the recoverability of deferred tax assets and establishes a valuation allowance when it is more likely than not that some portion or all the deferred tax assets will not be realized. Management makes judgments as to the interpretation of the tax laws that might be challenged upon an audit and cause changes to previous estimates of tax liability. In management’s opinion, adequate provisions for income taxes have been made. If actual taxable income by tax jurisdiction varies from estimates, additional allowances or reversals of reserves may be necessary. The Tax Cuts and Jobs Act (the “Tax Act”) was enacted on December 22, 2017. The Tax Act reduces the U.S. federal corporate tax rate from 35% to 21%. As of the completion of these unaudited condensed consolidated financial statements and related disclosures, we have made a reasonable estimate of the effects of the Tax Act. This estimate incorporates assumptions made based upon the Company’s current interpretation of the Tax Act, and may change as the Company may receive additional clarification and implementation guidance and as the interpretation of the Tax Act evolves. In accordance with the Securities and Exchange Commission (the “SEC”) Staff Accounting Bulletin No. 118, the Company will finalize the accounting for the effects of the Tax Act no later than the fourth quarter of 2018. Future adjustments made to the provisional effects will be reported as a component of income tax expense in the reporting period in which any such adjustments are determined. Based on the new tax law that lowers corporate tax rates, the Company revalued its deferred tax assets. Future tax benefits are expected to be lower, with the corresponding one time charge being recorded as a component of income tax expense. The Company is currently delinquent in the filing of its U.S. federal and state income tax returns for the years ended December 31, 2016 and 2015. The Company anticipates filing these returns on or before June 30, 2018.
Loss Per Share	Loss per share Basic loss per share is calculated by dividing net loss applicable to common shareholders by the weighted average number of common shares outstanding during the period. Diluted loss per share is calculated by dividing the net loss attributable to common shareholders by the sum of the weighted average number of common shares outstanding plus potential dilutive common shares outstanding during the period. Potential dilutive securities, comprised of unvested restricted shares, convertible debt stock warrants and stock options, are not reflected in diluted net loss per share because such potential shares are anti–dilutive due to the Company’s net loss. Accordingly, the computation of diluted loss per share for the three months ended March 31, 2018 excludes 2,000,000 shares issuable to the investors of the December 2017 private placement, 3,250,000 unvested restricted shares, 6,000,000 shares issuable under stock options, and 10,034,642 shares issuable under warrants. The computation of diluted loss per share for the three months ended March 31, 2017 excludes 1,500,000 unvested restricted shares, 6,000,000 shares issuable under options and 5,375,000 shares issuable under warrants, as they are anti–dilutive due to the Company’s net loss.
Stock-Based Compensation	Stock–based compensation The Company recognizes compensation expense for all equity–based payments in accordance with ASC 718 “Compensation – Stock Compensation”. Under fair value recognition provisions, the Company recognizes equity–based compensation net of an estimated forfeiture rate and recognizes compensation cost only for those shares expected to vest over the requisite service period of the award. Restricted stock awards are granted at the discretion of the compensation committee of the board of directors of the Company. These awards are restricted as to the transfer of ownership and generally vest over the requisite service periods, typically over a 12 to 24-month period (vesting on a straight–line basis). The fair value of a stock award is equal to the fair market value of a share of the Company’s common stock on the grant date. The fair value of an option award is estimated on the date of grant using the Black–Scholes option valuation model. The Black–Scholes option valuation model requires the development of assumptions that are inputs into the model. These assumptions are the expected stock volatility, the risk–free interest rate, the expected life of the option, the dividend yield on the underlying stock and the expected forfeiture rate. Expected volatility is calculated based on the historical volatility of the Company’s common stock over the expected term of the option. Risk–free interest rates are calculated based on continuously compounded risk–free rates for the appropriate term. Determining the appropriate fair value model and calculating the fair value of equity–based payment awards requires the input of the subjective assumptions described above. The assumptions used in calculating the fair value of equity–based payment awards represent management’s best estimates, which involve inherent uncertainties and the application of management’s judgment. The Company is required to estimate the expected forfeiture rate and recognize expense only for those shares expected to vest. The fair value of unvested equity instruments is re-measured each reporting period and such re-measured value is amortized over the requisite remaining service period. The Company accounts for share–based payments granted to non–employees in accordance with ASC 505–50, “Equity Based Payments to Non–Employees.” The Company determines the fair value of the stock–based payment as either the fair value of the consideration received or the fair value of the equity instruments issued, whichever is more readily determinable. If the fair value of the equity instruments issued is used, it is measured using the stock price and other measurement assumptions as of the earlier of either (1) the date at which a commitment for performance by the counterparty to earn the equity instruments is reached, or (2) the date at which the counterparty’s performance is complete.
Equity-linked Instruments	Equity-linked instruments The Company accounts for equity-linked instruments with certain anti-dilution provisions in accordance with ASC 815 and ASC 260. Under this guidance, the Company excludes instruments with certain down round features when determining whether a financial instrument (or embedded conversion feature) is considered indexed to the Company’s own stock. As a result, financial instruments (or embedded conversion features) with down round features are not required to be classified as derivative liabilities. The Company recoognizes the value of a down round feature only when it is triggered and the exercise or conversion price has been adjusted downward. For equity-classified freestanding financial instruments, such as warrants, the Company treats the value of the effect of the down round, when triggered, as a deemed dividend and a reduction of income available to common stockholders in computing basic earnings per share. For convertible instruments with embedded conversion features containing down round provisions, the Company recognizes the value of the down round as a beneficial conversion discount to be amortized to earnings.
Recent Accounting Pronouncements	Recent accounting pronouncements Management does not believe that any recently issued, but not yet effective accounting pronouncements, when adopted, will have a material effect on the accompanying unaudited condensed consolidated financial statements, other than those disclosed in the Company’s Annual Report on Form 10-K, filed with the SEC on April 2, 2018.
Management's Evaluation of Subsequent Events	Management’s Evaluation of Subsequent Events The Company evaluates events that have occurred after the balance sheet date but before the financial statements are issued. Based upon the review, other than what is described in Note 11 – Subsequent Events, the Company did not identify any recognized or non-recognized subsequent events that would have required adjustment or disclosure in the unaudited condensed consolidated financial statements.

Summary of Significant Accounting Policies (Policies)

3 Months Ended

Mar. 31, 2018

Principles of consolidation

The unaudited condensed consolidated financial statements include the accounts of MGT and its wholly owned subsidiaries. All intercompany transactions and balances have been eliminated. Non-controlling interest represents the non-controlling equity investment in MGT subsidiaries, plus the minority investors’ share of the net operating results and other components of equity relating to the non-controlling interest.

Reclassification

Reclassification

Certain amounts in prior periods have been reclassified to conform to current period presentation. These reclassifications had no effect on the previously reported net loss.

Use of Estimates and Assumptions and Critical Accounting Estimates and Assumptions

Use of estimates and assumptions and critical accounting estimates and assumptions

The preparation of financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and the disclosure of contingent assets and liabilities as of the date of the financial statements, and also affect the amounts of revenues and expenses reported for each period. Actual results could differ from those which result from using such estimates. Management utilizes various other estimates, including but not limited to determining the estimated lives of long-lived assets, determining the potential impairment of intangibles, the fair value of warrants issued, the fair value of stock options, the fair value of conversion features, the fair value of the deemed dividend, the recognition of revenue, the valuation allowance for deferred tax assets and other legal claims and contingencies. The results of any changes in accounting estimates are reflected in the financial statements in the period in which the changes become evident. Estimates and assumptions are reviewed periodically and the effects of revisions are reflected in the period that they are determined to be necessary.

Revenue Recognition

Revenue recognition

The Company recognizes revenue when it is realized or realizable and earned. The Company considers revenue realized or realizable and earned when there is persuasive evidence of an arrangement, delivery has occurred, the sales price is fixed or determinable and collectability is probable. The Company’s primary revenue stream is related to the mining of digital currencies. The Company derives its revenue by solving “blocks” to be added to the blockchain and providing transaction verification services within the digital currency networks of cryptocurrencies, such as Bitcoin and Ethereum, commonly termed “cryptocurrency mining.” In consideration for these services, the Company receives digital currency (“Coins”). The Coins are recorded as revenue, using the average spot price of Bitcoin on the date of receipt. The Coins are recorded on the balance sheet at their fair value and re–measured at each reporting date. Costs of revenues includes equipment depreciation, rent, and electricity costs. Revaluation gains or losses, as well gains or losses on sale of Coins are also recorded cost of revenue in the unaudited condensed consolidated statements of operations.

Income Taxes

Income taxes

The Company accounts for income taxes in accordance with Accounting Standards Codification (“ASC”) 740, “Income Taxes”. ASC 740 requires an asset and liability approach for financial accounting and reporting for income taxes and established for all the entities a minimum threshold for financial statement recognition of the benefit of tax positions, and requires certain expanded disclosures. The provision for income taxes is based upon income or loss after adjustment for those permanent items that are not considered in the determination of taxable income. Deferred income taxes represent the tax effects of differences between the financial reporting and tax basis of the Company’s assets and liabilities at the enacted tax rates in effect for the years in which the differences are expected to reverse. The Company evaluates the recoverability of deferred tax assets and establishes a valuation allowance when it is more likely than not that some portion or all the deferred tax assets will not be realized. Management makes judgments as to the interpretation of the tax laws that might be challenged upon an audit and cause changes to previous estimates of tax liability. In management’s opinion, adequate provisions for income taxes have been made. If actual taxable income by tax jurisdiction varies from estimates, additional allowances or reversals of reserves may be necessary.

The Tax Cuts and Jobs Act (the “Tax Act”) was enacted on December 22, 2017. The Tax Act reduces the U.S. federal corporate tax rate from 35% to 21%. As of the completion of these unaudited condensed consolidated financial statements and related disclosures, we have made a reasonable estimate of the effects of the Tax Act. This estimate incorporates assumptions made based upon the Company’s current interpretation of the Tax Act, and may change as the Company may receive additional clarification and implementation guidance and as the interpretation of the Tax Act evolves. In accordance with the Securities and Exchange Commission (the “SEC”) Staff Accounting Bulletin No. 118, the Company will finalize the accounting for the effects of the Tax Act no later than the fourth quarter of 2018. Future adjustments made to the provisional effects will be reported as a component of income tax expense in the reporting period in which any such adjustments are determined. Based on the new tax law that lowers corporate tax rates, the Company revalued its deferred tax assets. Future tax benefits are expected to be lower, with the corresponding one time charge being recorded as a component of income tax expense.

The Company is currently delinquent in the filing of its U.S. federal and state income tax returns for the years ended December 31, 2016 and 2015. The Company anticipates filing these returns on or before June 30, 2018.

Loss Per Share

Loss per share

Basic loss per share is calculated by dividing net loss applicable to common shareholders by the weighted average number of common shares outstanding during the period. Diluted loss per share is calculated by dividing the net loss attributable to common shareholders by the sum of the weighted average number of common shares outstanding plus potential dilutive common shares outstanding during the period. Potential dilutive securities, comprised of unvested restricted shares, convertible debt stock warrants and stock options, are not reflected in diluted net loss per share because such potential shares are anti–dilutive due to the Company’s net loss.

Accordingly, the computation of diluted loss per share for the three months ended March 31, 2018 excludes 2,000,000 shares issuable to the investors of the December 2017 private placement, 3,250,000 unvested restricted shares, 6,000,000 shares issuable under stock options, and 10,034,642 shares issuable under warrants. The computation of diluted loss per share for the three months ended March 31, 2017 excludes 1,500,000 unvested restricted shares, 6,000,000 shares issuable under options and 5,375,000 shares issuable under warrants, as they are anti–dilutive due to the Company’s net loss.

Stock-Based Compensation

Stock–based compensation

The Company recognizes compensation expense for all equity–based payments in accordance with ASC 718 “Compensation – Stock Compensation”. Under fair value recognition provisions, the Company recognizes equity–based compensation net of an estimated forfeiture rate and recognizes compensation cost only for those shares expected to vest over the requisite service period of the award.

Restricted stock awards are granted at the discretion of the compensation committee of the board of directors of the Company. These awards are restricted as to the transfer of ownership and generally vest over the requisite service periods, typically over a 12 to 24-month period (vesting on a straight–line basis). The fair value of a stock award is equal to the fair market value of a share of the Company’s common stock on the grant date.

The fair value of an option award is estimated on the date of grant using the Black–Scholes option valuation model. The Black–Scholes option valuation model requires the development of assumptions that are inputs into the model. These assumptions are the expected stock volatility, the risk–free interest rate, the expected life of the option, the dividend yield on the underlying stock and the expected forfeiture rate. Expected volatility is calculated based on the historical volatility of the Company’s common stock over the expected term of the option. Risk–free interest rates are calculated based on continuously compounded risk–free rates for the appropriate term.

Determining the appropriate fair value model and calculating the fair value of equity–based payment awards requires the input of the subjective assumptions described above. The assumptions used in calculating the fair value of equity–based payment awards represent management’s best estimates, which involve inherent uncertainties and the application of management’s judgment. The Company is required to estimate the expected forfeiture rate and recognize expense only for those shares expected to vest. The fair value of unvested equity instruments is re-measured each reporting period and such re-measured value is amortized over the requisite remaining service period.

The Company accounts for share–based payments granted to non–employees in accordance with ASC 505–50, “Equity Based Payments to Non–Employees.” The Company determines the fair value of the stock–based payment as either the fair value of the consideration received or the fair value of the equity instruments issued, whichever is more readily determinable. If the fair value of the equity instruments issued is used, it is measured using the stock price and other measurement assumptions as of the earlier of either (1) the date at which a commitment for performance by the counterparty to earn the equity instruments is reached, or (2) the date at which the counterparty’s performance is complete.

Equity-linked Instruments

Equity-linked instruments

The Company accounts for equity-linked instruments with certain anti-dilution provisions in accordance with ASC 815 and ASC 260. Under this guidance, the Company excludes instruments with certain down round features when determining whether a financial instrument (or embedded conversion feature) is considered indexed to the Company’s own stock. As a result, financial instruments (or embedded conversion features) with down round features are not required to be classified as derivative liabilities. The Company recoognizes the value of a down round feature only when it is triggered and the exercise or conversion price has been adjusted downward. For equity-classified freestanding financial instruments, such as warrants, the Company treats the value of the effect of the down round, when triggered, as a deemed dividend and a reduction of income available to common stockholders in computing basic earnings per share. For convertible instruments with embedded conversion features containing down round provisions, the Company recognizes the value of the down round as a beneficial conversion discount to be amortized to earnings.

Recent Accounting Pronouncements

Recent accounting pronouncements

Management does not believe that any recently issued, but not yet effective accounting pronouncements, when adopted, will have a material effect on the accompanying unaudited condensed consolidated financial statements, other than those disclosed in the Company’s Annual Report on Form 10-K, filed with the SEC on April 2, 2018.

Management's Evaluation of Subsequent Events

Management’s Evaluation of Subsequent Events

The Company evaluates events that have occurred after the balance sheet date but before the financial statements are issued. Based upon the review, other than what is described in Note 11 – Subsequent Events, the Company did not identify any recognized or non-recognized subsequent events that would have required adjustment or disclosure in the unaudited condensed consolidated financial statements.