Debt - Schedule of Debt (Details) - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
Long-term debt and capital lease obligations, including current portion	$ 955.1	$ 1,034.6
Less current portion	(8.2)	(13.0)
Long-term debt and capital lease obligations	946.9	1,021.6
Senior Notes [Member] \| 8.375% senior secured notes due 2019 [Member]
Debt Instrument [Line Items]
Long-term debt and capital lease obligations, including current portion	0.0	220.0
Senior Notes [Member] \| 7.75% senior unsecured notes due 2021 [Member]
Debt Instrument [Line Items]
Long-term debt and capital lease obligations, including current portion	465.0	465.0
Line of Credit [Member] \| Other Lines of Credit [Member]
Debt Instrument [Line Items]
Long-term debt and capital lease obligations, including current portion	7.8	9.2
Line of Credit [Member] \| Secured Debt [Member] \| Senior secured term loan facility due March 2020 [Member]
Debt Instrument [Line Items]
Long-term debt and capital lease obligations, including current portion	0.0	338.7
Line of Credit [Member] \| Secured Debt [Member] \| Senior secured term loan facility due September 2020 [Member]
Debt Instrument [Line Items]
Long-term debt and capital lease obligations, including current portion	481.3	0.0
Capital Lease Obligations and Other [Member]
Debt Instrument [Line Items]
Long-term debt and capital lease obligations, including current portion	$ 1.0	$ 1.7

Amount of short-term debt and current maturity of long-term debt and capital lease obligations due within one year or the normal operating cycle, if longer.

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

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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

- Definition

Amount of long-term debt and capital lease obligation due after one year or beyond 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 210.5-02.22)

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

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

-Publisher SEC

-Name Staff Accounting Bulletin (SAB)

-Number Topic 6

-Section H

+ Details

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

- Definition

Amount of long-term debt and capital lease obligations including current maturities.

+ References

No definition available.

+ Details

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

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_SeniorNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=mcrn_SeniorSecuredNotesDue2019Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=mcrn_SeniorUnsecuredNotesDue2021Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_LineOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=mcrn_OtherLinesOfCreditMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_CreditFacilityAxis=us-gaap_SecuredDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=mcrn_SeniorSecuredTermLoanFacilityDueMarch2020Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=mcrn_SeniorSecuredTermLoanFacilityDueSeptember2020Member
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=mcrn_CapitalLeaseObligationsandOtherMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type: