Represents the notice period required for termination of contract.

No definition available.

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Namespace Prefix:	mgln_
Data Type:	xbrli:durationItemType
Balance Type:	na
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- Definition

Represents the term of the contract entered with the customer.

+ References

No definition available.

+ Details

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Namespace Prefix:	mgln_
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Balance Type:	na
Period Type:	duration

- Definition

Represents the term of the renewed contract with the customer.

+ References

No definition available.

+ Details

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Namespace Prefix:	mgln_
Data Type:	xbrli:durationItemType
Balance Type:	na
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- Definition

Amount due from customers or clients, within one year of the balance sheet date (or the normal operating cycle, whichever is longer), for goods or services (including trade receivables) that have been delivered or sold in the normal course of business, reduced to the estimated net realizable fair value by an allowance established by the entity of the amount it deems uncertain of collection.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(3))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(4))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- 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

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

- Definition

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).

+ References

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

+ Details

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

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MajorCustomersAxis=mgln_GeographicConcentrationRiskAreaOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_MajorCustomersAxis=mgln_CentersForMedicareAndMedicaidServicesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

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Namespace Prefix:
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Period Type:

General - Concentration of Business (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017
Operating results by business segment
Revenues	$ 1,810,923	$ 1,419,139	$ 3,616,000	$ 2,724,762
Accounts receivable, net	839,773		$ 839,773		$ 660,775
Minimum
Operating results by business segment
Term of contracts with customers			1 year
Term of renewal contracts			1 year
Notice period for termination of contract			30 days
Maximum
Operating results by business segment
Term of contracts with customers			3 years
Term of renewal contracts			2 years
Notice period for termination of contract			180 days
Pennsylvania Counties
Operating results by business segment
Revenues			$ 275,300	232,400
CMS
Operating results by business segment
Revenues			205,100	236,100
Accounts receivable, net	$ 119,800		119,800		$ 131,500
United States federal government
Operating results by business segment
Revenues			$ 165,800	$ 177,500