XML 59 R44.htm IDEA: XBRL DOCUMENT
v3.19.1

Segment Information - Additional Information (Detail) - 3 months ended Mar. 31, 2019 | Total | Property | States | Communities
--- | --- | --- | --- | ---
Segment Reporting Information [Line Items] |  |  |  |
Number of owned or owned interests of apartment communities |  | 303 |  | 303
Number of States in which Entity Operates |  |  | 17 |
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 |  |  |

X
- 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

X
- 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

X
- 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

X
- 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

X
- 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

X
- 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

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