General - Leases - Maturity Dates (Details) $ in Thousands	Mar. 31, 2021 USD ($)
Leases
2020	$ 11,819
2021	14,893
2022	12,399
2023	10,616
2024	5,358
2025 and beyond	5,556
Total lease payments	$ 60,641

Amount of lessee's undiscounted obligation for lease payments for operating and finance leases.

No definition available.

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- Definition

Amount of lessee's undiscounted obligation for lease payments for operating and finance lease, due after fifth fiscal year following latest fiscal year.

+ References

No definition available.

+ Details

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- Definition

Amount of lessee's undiscounted obligation for lease payments for operating and finance lease, due in fifth fiscal year following latest fiscal year.

+ References

No definition available.

+ Details

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Namespace Prefix:	mgln_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of lessee's undiscounted obligation for lease payments for operating and finance lease, due in fourth fiscal year following latest fiscal year.

+ References

No definition available.

+ Details

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

- Definition

Amount of lessee's undiscounted obligation for lease payments for operating and finance lease, due in third fiscal year following latest fiscal year.

+ References

No definition available.

+ Details

Name:	mgln_LeaseLiabilityPaymentsDueYearThree
Namespace Prefix:	mgln_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of lessee's undiscounted obligation for lease payments for operating and finance lease, due in second fiscal year following latest fiscal year.

+ References

No definition available.

+ Details

Name:	mgln_LeaseLiabilityPaymentsDueYearTwo
Namespace Prefix:	mgln_
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Balance Type:	credit
Period Type:	instant

- Definition

Amount of lessee's undiscounted obligation for lease payments for operating and finance lease, due in remainder of fiscal year following latest fiscal year ended.

+ References

No definition available.

+ Details

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Namespace Prefix:	mgln_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- References

No definition available.

+ Details

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