v3.7.0.1

Lease Commitments - Additional Information (Detail) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2016 | Dec. 31, 2015 | Dec. 31, 2014
Capital Leases And Operating Leases [Line Items] |  |  |
Rental expense for operating leases | $ 14.5 | $ 12.9 | $ 12.4
Maximum |  |  |
Capital Leases And Operating Leases [Line Items] |  |  |
Lease Expiration Year | 2036 |  |

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- Definition Capital leases and operating leases. + References No definition available. + Details
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- Definition Lease expiration year. + References No definition available. + Details
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Namespace Prefix: | mpg_
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- Definition Rental expense for the reporting period incurred under operating leases, including minimum and any contingent rent expense, net of related sublease income. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 840 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6453985&loc=d3e41499-112717 + Details
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- Details
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