Basis of Presentation (Details Textual) (USD $) In Thousands, unless otherwise specified	3 Months Ended	6 Months Ended
Jun. 30, 2012 Investor	Jun. 30, 2012
Basis of Presentation (Textual) [Abstract]
Number of investors that sold stock resulting in cumulative participation securities payments in excess of original investment basis	1
Investor payment to Walmart for full settlement under the Participation Agreement		$ 347

Noncash capital contribution resulting from one or more of the entity's investors selling its interest in the entity's common stock to an unrelated third party causing a liquidity event.

No definition available.

Name:	mgi_AdjustmentsToAdditionalPaidInCapitalContributionOfCapitalFromInvestors
Namespace Prefix:	mgi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration