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v3.20.2

Leases - Narrative (Details) | 6 Months Ended
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Jun. 30, 2020 lease
Leases [Abstract] |
Number of finance leases | 5

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- Definition Finance Lease, Number of Leases + References No definition available. + Details
Name: | mac_FinanceLeaseNumberofLeases
Namespace Prefix: | mac_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

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- References No definition available. + Details
Name: | us-gaap_LeasesAbstract
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration