Basis rate for fees on unused availability under revolving credit facility.

No definition available.

Name:	mgi_BasisRateForFeesOnUnusedAvailabilityUnderRevolvingCreditFacility
Namespace Prefix:	mgi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Deferred financing costs capitalized during the reporting period.

+ References

No definition available.

+ Details

Name:	mgi_CapitalizedDeferredFinancingCosts
Namespace Prefix:	mgi_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Basis point spread added to the treasury rate used to calculate the greater of two different prepayment premiums.

+ References

No definition available.

+ Details

Name:	mgi_DebtInstrumentBasisPointSpreadForPrepaymentPremium
Namespace Prefix:	mgi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage of the principal amount of the debt instrument used to calculate the greater of two different prepayment premiums.

+ References

No definition available.

+ Details

Name:	mgi_DebtInstrumentPercentageOfPrincipalForPrepaymentPremium
Namespace Prefix:	mgi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The principal amount of the debt instrument to be paid in quarterly increments.

+ References

No definition available.

+ Details

Name:	mgi_DebtInstrumentPrincipalAmountToBePaidInQuarterlyIncrements
Namespace Prefix:	mgi_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of incremental debt payments due on a quarterly basis.

+ References

No definition available.

+ Details

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

- Details

Name:	mgi_DebtTextualAbstract
Namespace Prefix:	mgi_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Minimum liquidity ratio.

+ References

No definition available.

+ Details

Name:	mgi_MinimumLiquidityRatio
Namespace Prefix:	mgi_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Redemption price expressed as a percentage of the principal amount of the debt instrument.

+ References

No definition available.

+ Details

Name:	mgi_RedemptionPriceAsPercentageOfPrincipal
Namespace Prefix:	mgi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Repurchase price of the debt instrument upon a change of control, stated as a percentage of the principal balance.

+ References

No definition available.

+ Details

Name:	mgi_RepurchasePriceUponChangeOfControlPercentage
Namespace Prefix:	mgi_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

The percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

When presenting a range of interest rates, the lowest stated (contractual) rate for funds borrowed under the debt agreement as of the balance sheet date.

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 22

-Article 5

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.22(a)(2))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_DebtInstrumentInterestRateStatedPercentageRateRangeMinimum
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Details

Name:	us-gaap_DebtInstrumentLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of cash paid for interest during the period.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6367179&loc=d3e4297-108586

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 95

-Paragraph 29

-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.

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 25

-Subparagraph (e)

-URI http://asc.fasb.org/extlink&oid=6943989&loc=d3e3536-108585

+ Details

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

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

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

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.19(b),22(b))

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 19, 22

-Article 5

+ Details

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

- Definition

Amount of long-term debt, sinking fund requirements, and other securities redeemable at fixed or determinable prices and dates maturing after the fifth fiscal year following the latest fiscal year.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 470

-SubTopic 10

-Section 50

-Paragraph 1

-URI http://asc.fasb.org/extlink&oid=6802200&loc=d3e1835-112601

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 47

-Paragraph 10

-Subparagraph b

-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

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

- Definition

Amount of long-term debt, sinking fund requirements, and other securities redeemable at fixed or determinable prices and dates maturing in the fifth fiscal year following the latest fiscal year.

+ References

+ Details

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

Debt (Details Textual) (USD $) In Millions, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2012	Jun. 30, 2011	Jun. 30, 2012	Jun. 30, 2011
Debt (Textual) [Abstract]
Outstanding letters of credit	$ 12.7		$ 12.7
Interest paid	15.9	20.0	32.4	38.7
Debt maturing in 2017	481.0		481.0
Debt maturing in 2018	325.0		325.0
Incremental payment of debt principal	7.9		7.9
Increment paid			0.4
2011 Credit Agreement [Member]
Debt Instrument [Line Items]
Capitalized deferred financing costs		12.8
Second lien notes [Member]
Debt Instrument [Line Items]
Repurchase price upon change of control			101.00%
Minimum liquidity ratio			1
Capitalized deferred financing costs		5.0
Second lien notes [Member] \| Prior to fifth anniversary [Member]
Debt Instrument [Line Items]
Redemption price as a percentage of principal			100.00%
Debt instrument percentage of principal for prepayment premium			1.00%
Basis point on treasury rate			0.50%
Second lien notes [Member] \| Fifth anniversary [Member]
Debt Instrument [Line Items]
Redemption price as a percentage of principal			107.00%
Second lien notes [Member] \| On or after eighth anniversary [Member]
Debt Instrument [Line Items]
Redemption price as a percentage of principal			100.00%
Senior revolving credit facility [Member] \| 2011 Credit Agreement [Member]
Debt Instrument [Line Items]
Revolving credit facility, fees on daily unused availability			0.625%
Revolving credit facility, availability	$ 137.3		$ 137.3
BOA Prime Rate [Member] \| 2011 Credit Agreement [Member]
Debt Instrument [Line Items]
Basis spread on variable interest rate	2.25%		2.25%
Eurodollar Rate [Member] \| 2011 Credit Agreement [Member]
Debt Instrument [Line Items]
Basis spread on variable interest rate	3.00%		3.00%
Minimum Eurodollar rate			1.25%