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The percentage of holdback considered as contingent liability.

No definition available.

Name:	mrc_PercentageOfHoldbackConsideredAsContingentLiability
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Data Type:	dtr-types:percentItemType
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The percentage of holdback reduced by stabilization costs.

No definition available.

Name:	mrc_PercentageOfHoldbackReducedByStabilizationCosts
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Data Type:	dtr-types:percentItemType
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The percentage of reduced purchase price paid at closing for the general partnership interest.

No definition available.

Name:	mrc_PercentageOfReducedPurchasePriceForGeneralPartnershipInterest
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Data Type:	dtr-types:percentItemType
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Amount of written off contingent consideration in noncash financing activities.

No definition available.

Name:	mrc_WrittenOffContingentConsideration
Namespace Prefix:	mrc_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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- References

No definition available.

Name:	us-gaap_BusinessCombinationContingentConsiderationArrangementsAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
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Amount of liability recognized arising from contingent consideration in a business combination.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 805
-SubTopic 30
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (c)(1)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479581/805-30-50-1

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 25
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479668/805-30-25-6

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 35
-Paragraph 1
-Subparagraph (b)
-SubTopic 30
-Topic 805
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147479613/805-30-35-1

Name:	us-gaap_BusinessCombinationContingentConsiderationLiability
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Data Type:	xbrli:monetaryItemType
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Amount of cash outflow, made soon after acquisition date of business combination, to settle contingent consideration liability.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 45
-Paragraph 13
-Subparagraph (d)
-SubTopic 10
-Topic 230
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482740/230-10-45-13