Name:	mgln_DirectServiceCostsAndOtherOperatingExpenses
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

The add back of the change in the fair value of contingent consideration, (excluding the portion that is recorded as interest expense) that is included in direct service costs and other operating expenses but is excluded from the computation of segment profit since it is managed on a consolidated basis..

No definition available.

Name:	mgln_ReconciliationOfSegmentProfitLossChangeInFairValueOfContingentConsiderationAddBack
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Data Type:	xbrli:monetaryItemType
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The noncontrolling portion of segment profit that is excluded from the computation of segment profit.

No definition available.

Name:	mgln_ReconciliationOfSegmentProfitLossNoncontrollingInterestProfitLoss
Namespace Prefix:	mgln_
Data Type:	xbrli:monetaryItemType
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The add back of stock compensation expense that is included in direct service costs and other operating expenses but is excluded from the computation of segment profit since it is managed on a consolidated basis.

No definition available.

Name:	mgln_ReconciliationOfSegmentProfitLossShareBasedCompensationExpenseAddback
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Data Type:	xbrli:monetaryItemType
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Non-GAAP measure representing aggregate segment revenue less cost of goods and services, other operating and non-operating expenses, and non-controlling interest.

No definition available.

Name:	mgln_SegmentProfitLoss
Namespace Prefix:	mgln_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

The aggregate costs related to goods produced and sold and services rendered by an entity during the reporting period. This excludes costs incurred during the reporting period related to financial services rendered and other revenue generating activities.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.2(a),(d))
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

Name:	us-gaap_CostOfGoodsAndServicesSold
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Data Type:	xbrli:monetaryItemType
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Period Type:	duration

Total costs of health care costs, net of recoveries of stop-loss insurance. Costs of services rendered (including costs of services rendered but not yet reported).

No definition available.

Name:	us-gaap_HealthCareOrganizationExpensesNet
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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

Name:	us-gaap_Revenues
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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.

No definition available.

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

Name:	us-gaap_ProductOrServiceAxis=mgln_ManagedCareAndOtherMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_ProductOrServiceAxis=mgln_PharmacyBenefitManagementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_ConsolidationItemsAxis=us-gaap_OperatingSegmentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_StatementBusinessSegmentsAxis=mgln_HealthCareMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Name:	us-gaap_StatementBusinessSegmentsAxis=mgln_PharmacySolutionsMember
Namespace Prefix:
Data Type:	na
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Period Type: