Stock incentive plan and share-based compensation (Details 2) (Warrant [Member], USD $)	3 Months Ended
Mar. 31, 2013
Warrant [Member]
Number of shares - Warrants outstanding at December 31, 2012	4,038,753
Number of shares - Issued	0
Number of shares - Exercised	0
Number of shares - Expired	0
Number of shares - Warrants outstanding at March 31, 2013	4,038,753
Weighted average exercise price - Warrants outstanding at December 31, 2012	$ 3.68
Weighted average exercise price - Issued	$ 0
Weighted average exercise price - Exercised	$ 0
Weighted average exercise price - Expired	$ 0
Weighted average exercise price - Warrants outstanding at March 31, 2013	$ 3.68

The number of share based compensation arrangement by share based payment award warrants exercised.

No definition available.

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The number of share based compensation arrangement by share based payment award warrants expired.

No definition available.

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The number of share based compensation arrangement by share based payment award warrants issued.

No definition available.

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The number of share based compensation arrangement by share based payment award warrants outstanding.

No definition available.

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Namespace Prefix:	mgt_
Data Type:	xbrli:sharesItemType
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Represents share based compensation arrangement by share based payment award weighted average exercise price warrants exercised.

No definition available.

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Data Type:	num:perShareItemType
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Represents share based compensation arrangement by share based payment award weighted average exercise price warrants expired.

No definition available.

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Represents share based compensation arrangement by share based payment award weighted average exercise price warrants issued.

No definition available.

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Namespace Prefix:	mgt_
Data Type:	num:perShareItemType
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Represents share based compensation arrangement by share based payment award weighted average exercise price warrants outstanding.

No definition available.

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Namespace Prefix:	mgt_
Data Type:	num:perShareItemType
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Period Type:	instant