Accrued Expenses - Summary of Accrued Expenses (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013
Payables and Accruals [Abstract]
Payroll, benefits and related taxes, excluding severance benefits	$ 18,654	$ 19,869
Withholding tax levied on intercompany interest income	27,497us-gaap_TaxesPayableCurrent	23,872us-gaap_TaxesPayableCurrent
Interest on senior notes	7,040us-gaap_InterestPayableCurrent	6,749us-gaap_InterestPayableCurrent
Settlement obligations	8,976us-gaap_SettlementLiabilitiesCurrent	6,460us-gaap_SettlementLiabilitiesCurrent
Outside service fees	10,640mx_AccruedOutsideServiceFeesCurrent	1,462mx_AccruedOutsideServiceFeesCurrent
Others	8,253us-gaap_OtherAccruedLiabilitiesCurrent	7,082us-gaap_OtherAccruedLiabilitiesCurrent
Accrued expenses	$ 81,060us-gaap_AccruedLiabilitiesCurrent	$ 65,494us-gaap_AccruedLiabilitiesCurrent

Accrued Outside Service Fees Current

No definition available.

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- Definition

Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Examples include taxes, interest, rent and utilities. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

+ References

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- Definition

Total of the carrying values as of the balance sheet date of obligations incurred through that date and payable for obligations related to services received from employees, such as accrued salaries and bonuses, payroll taxes and fringe benefits. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

+ References

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- Definition

Carrying value as of the balance sheet date of [accrued] interest payable on all forms of debt, including trade payables, that has been incurred and is unpaid. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 20

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-Publisher FASB

-Name Accounting Standards Codification

-Glossary Current Liabilities

-URI http://asc.fasb.org/extlink&oid=6509677

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

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-Section 45

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- Definition

Carrying value as of the balance sheet date of obligations incurred through that date and payable arising from transactions not otherwise specified in the taxonomy. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

+ References

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 20

-Article 5

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

-Publisher FASB

-Name Accounting Standards Codification

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-Publisher FASB

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- Definition

Amounts payable for money transfers, money orders, and consumer payment service arrangements. Settlement liabilities include amounts payable to intermediaries for global payment transfers.

+ References

No definition available.

+ Details

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- Definition

Carrying value as of the balance sheet date of obligations incurred and payable for statutory income, sales, use, payroll, excise, real, property and other taxes. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

+ 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 210.5-02.19,20)

-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 20

-Article 5

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

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