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SIGNIFICANT ACCOUNTING POLICIES (Detail Textuals 3) | 12 Months Ended
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Dec. 31, 2014
Schedule of Available-for-sale Securities [Line Items] |
Period of current marketable securities | less than 12 months
Period of non-current marketable securities | greater than 12 months
Municipal debt obligations | A- or higher |
Schedule of Available-for-sale Securities [Line Items] |
Period of maturity debt obligations | less than one year to over 10 years
Corporate obligations | A- or higher |
Schedule of Available-for-sale Securities [Line Items] |
Period of maturity debt obligations | one to five years

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- Definition This element represents period of current marketable securities. + References No definition available. + Details
Name: | mpx_PeriodOfCurrentMarketableSecurities
Namespace Prefix: | mpx_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents the maturity period of marketable securities. + References No definition available. + Details
Name: | mpx_PeriodOfMaturityOfMarketableSecurities
Namespace Prefix: | mpx_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Describe the approximate term of the non-current marketable securities. + References No definition available. + Details
Name: | mpx_PeriodOfNonCurrentMarketableSecurities
Namespace Prefix: | mpx_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_ScheduleOfAvailableForSaleSecuritiesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_DebtSecurityAxis=us-gaap_CorporateDebtSecuritiesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtSecurityAxis=us-gaap_MunicipalNotesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |