Represents the aggregate annual rent payment associated with the contributed lease properties within the Pension Plan.

No definition available.

Name:	mni_AggregateAnnualRentPaymentsOnContributedProperty
Namespace Prefix:	mni_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represents liabilities recorded by the entity related to financing obligations created by the entity's continuing involvement in properties sold or donated.

+ References

No definition available.

+ Details

Name:	mni_FinancingObligationsNotLongTermDebt
Namespace Prefix:	mni_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represents the amount of gain (loss) on value of property contributed.

+ References

No definition available.

+ Details

Name:	mni_GainLossOnContributionOfProperty
Namespace Prefix:	mni_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The lease term for properties which the entity contributed to its pension plan and then leased back.

+ References

No definition available.

+ Details

Name:	mni_LeaseTermOfContributedProperty
Namespace Prefix:	mni_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- References

No definition available.

+ Details

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

- Definition

Amount of contributions made by the employer to defined benefit plans.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(5)(ii)
-URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 60
-Section 35
-Paragraph 123
-Subparagraph B
-URI http://asc.fasb.org/extlink&oid=64937487&loc=d3e36068-114959

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 30
-Section 35
-Paragraph 63
-Subparagraph B
-URI http://asc.fasb.org/extlink&oid=64937038&loc=d3e12551-114930

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
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-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (d)(5)(iv)(01)
-URI http://asc.fasb.org/extlink&oid=65897934&loc=d3e1928-114920

+ Details

Name:	us-gaap_DefinedBenefitPlanContributionsByEmployer
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Details

Name:	us-gaap_DefinedBenefitPlansDisclosuresDefinedBenefitPlansAxis=us-gaap_PensionPlansDefinedBenefitMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

EMPLOYEE BENEFITS - Contributions (Details) - USD ($)	1 Months Ended	6 Months Ended
EMPLOYEE BENEFITS - Contributions (Details) - USD ($)	Feb. 29, 2016	Jun. 25, 2017	Dec. 25, 2016
Medical cost trend rates
Financing obligations		$ 52,330,000	$ 51,616,000
Pension plan
Medical cost trend rates
Value of contributions to plan	$ 47,100,000
Term of leases entered into for property contributed to pension plan	11 years
Gain or loss recognized on the contribution of property		$ 0
Aggregate Annual Rent Payments On Contributed Property	$ 3,500,000