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v3.19.3

Segment Information - Additional Information (Details) | 9 Months Ended
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Sep. 30, 2019 Property State Segment
Segment Reporting Information [Line Items] |
Number of owned or owned interests of apartment communities | Property | 303
Number of States in which Entity Operates | State | 17
Number of reportable segments | Segment | 2
Period properties owned and stabilized | 12 months
Occupancy Level for Stabilized Communities | 90.00%
Period Properties Stabilized | 90 days
Same Store [Member] |
Segment Reporting Information [Line Items] |
Period properties owned and stabilized | 12 months

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- Definition Occupancy level for stabilized communities. + References No definition available. + Details
Name: | maa_OccupancyLevelForStabilizedCommunities
Namespace Prefix: | maa_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

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- Definition Period properties owned and stabilized + References No definition available. + Details
Name: | maa_PeriodPropertiesOwnedAndStabilized
Namespace Prefix: | maa_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

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- Definition Period Properties Stabilized + References No definition available. + Details
Name: | maa_PeriodPropertiesStabilized
Namespace Prefix: | maa_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

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- Definition The number of real estate properties owned as of the balance sheet date. + References No definition available. + Details
Name: | us-gaap_NumberOfRealEstateProperties
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

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- Definition Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements. + References No definition available. + Details
Name: | us-gaap_NumberOfReportableSegments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

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- Definition The number of states the entity operates in as of the balance sheet date. + References No definition available. + Details
Name: | us-gaap_NumberOfStatesInWhichEntityOperates
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

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

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- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=maa_SameStoreMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |