Derivative liability - warrants (restated) (Details 1) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended	3 Months Ended
Sep. 30, 2012	Sep. 30, 2012	Sep. 30, 2012 Fair Value, Inputs, Level 3 [Member]	Dec. 31, 2011 Fair Value, Inputs, Level 3 [Member]
Balance, July 1, 2012		$ 1,461		$ 1,461
Change in fair value of warrant liability	(623)	(13)	(623)
Issuance of additional warrants due to anti-dilution provision	97		97
Transfers in and/or out of Level III	0		0
Balance, September 30, 2012	$ 935	$ 935	$ 935	$ 1,461

Represents the issuance of additional warrants during the period.

No definition available.

Name:	mgt_FairValueMeasurementIssuanceOfAdditionalWarrants
Namespace Prefix:	mgt_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of gain (loss) recognized in earnings, arising from liabilities measured at fair value on a recurring basis using unobservable inputs (level 3).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (c)(1)

-URI http://asc.fasb.org/extlink&oid=7578670&loc=d3e19207-110258

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 157

-Paragraph 32

-Subparagraph c(1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

This element represents [net] transfers in to and out of liabilities measured at fair value on a recurring basis using unobservable inputs (Level 3) which have taken place during the period.

+ References

No definition available.

+ Details

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityTransfersNet
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

This element represents a liability measured at fair value using significant unobservable inputs (Level 3) which is required for reconciliation purposes of beginning and ending balances.

+ References

+ Details

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant