Commitments and Contingencies (Details Textual 3) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012
Loss Contingencies [Line Items]
Cash payment required if petition is denied	$ 110.1
Goldman Sachs & Co. [Member]
Loss Contingencies [Line Items]
Percentage of common stock on diluted basis	19.00%

Cash payment required if the entity's petition in the United States Tax Court is denied in its entirety.

No definition available.

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Namespace Prefix:	mgi_
Data Type:	xbrli:monetaryItemType
Balance Type:	na
Period Type:	instant