The number of times a contract may be renewed under a contract agreement.

No definition available.

Name:	mgln_NumberOfContractRenewals
Namespace Prefix:	mgln_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Represents the term of the contract entered with the customer.

+ References

No definition available.

+ Details

Name:	mgln_TermOfContract
Namespace Prefix:	mgln_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Represents the term of the renewed contract with the customer.

+ References

No definition available.

+ Details

Name:	mgln_TermOfRenewedContract
Namespace Prefix:	mgln_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of days required for a customer to have the right to terminate a contract for cause.

+ References

No definition available.

+ Details

Name:	mgln_TerminationClauseNumberOfDaysNoticeToTerminate
Namespace Prefix:	mgln_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of revenue attributable to disposal group, including, but not limited to, discontinued operation.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 5B
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109222650&loc=SL51721673-107760

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 20
-Section 50
-Paragraph 7
-URI http://asc.fasb.org/extlink&oid=109222650&loc=SL51721683-107760

+ Details

Name:	us-gaap_DisposalGroupIncludingDiscontinuedOperationRevenue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

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

- Details

Name:	us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis=mgln_MagellanCompleteCareBusinessMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DisposalGroupClassificationAxis=us-gaap_DiscontinuedOperationsHeldforsaleMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_MajorCustomersAxis=mgln_VirginiaContractsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_MajorCustomersAxis=mgln_CccPlusContractMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_MajorCustomersAxis=mgln_MedallionContractMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_MajorCustomersAxis=mgln_NewYorkContractsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_MajorCustomersAxis=mgln_MassachusettsContractsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_MajorCustomersAxis=mgln_SCOContractMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_MajorCustomersAxis=mgln_CmsContractMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

General - Customers Exceeding Ten Percent of Consolidated Net Revenues (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020 USD ($) item	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) item	Sep. 30, 2019 USD ($)
MCC Business \| Discontinued Operations, Held-for-sale
Significant customers
Managed care and other revenue	$ 744,741	$ 713,089	$ 2,200,132	$ 2,045,474
Maximum
Significant customers
Term of contracts with customers			3 years
Term of contract extensions or renewals			2 years
Virginia Contracts \| MCC Business \| Discontinued Operations, Held-for-sale
Significant customers
Managed care and other revenue			$ 741,600	614,100
CCC Plus Contract
Significant customers
Term of contracts with customers			5 years
Term of contract extensions or renewals			12 months
Termination notice			90 days
CCC Plus Contract \| Maximum
Significant customers
Number of contract extensions or renewals \| item	5		5
Medallion Contract
Significant customers
Number of contract extensions or renewals \| item	6		6
Term of contract extensions or renewals			12 months
Termination notice			180 days
New York Contract
Significant customers
Managed care and other revenue			$ 576,600	623,400
Massachusetts Contracts \| MCC Business \| Discontinued Operations, Held-for-sale
Significant customers
Managed care and other revenue			$ 537,000	$ 541,900
SCO Contract
Significant customers
Term of contract extensions or renewals			1 year
Termination notice			180 days
SCO Contract \| Maximum
Significant customers
Number of contract extensions or renewals \| item	5		5
CMS Contract
Significant customers
Term of contracts with customers			1 year