XML 67 R43.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Business Combinations (Textual) (Details) $ / shares in Units, ft² in Thousands |  | 3 Months Ended | 12 Months Ended
--- | --- | --- | ---
Dec. 01, 2016 USD ($) ft² Communities properties $ / shares shares | Dec. 31, 2017 USD ($) shares | Sep. 30, 2017 USD ($) | Jun. 30, 2017 USD ($) | Mar. 31, 2017 USD ($) | Dec. 31, 2016 USD ($) shares | Sep. 30, 2016 USD ($) | Jun. 30, 2016 USD ($) | Mar. 31, 2016 USD ($) | Dec. 31, 2017 USD ($) shares | Dec. 31, 2016 USD ($) shares | Dec. 31, 2015 USD ($)
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Business Combinations, Other Consideration | $ 2,000,000 |  |  |  |  |  |  |  |  |  |  |
Business Combination, Merger and Integration Related Expenses |  |  |  |  |  |  |  |  |  |  | $ 40,800,000 |
Redeemable Preferred Stock [Member] |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Embedded Derivative, Fair Value of Embedded Derivative Asset | 14.24 |  |  |  |  |  |  |  |  |  |  |
Mandatorily Redeemable Preferred Stock, Fair Value Disclosure | $ 77.00 |  |  |  |  |  |  |  |  |  |  |
Preferred Stock, Shares Outstanding | shares | 867,846 |  |  |  |  |  |  |  |  |  |  |
Unsecured Debt |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Business Combination, Consideration Transferred, Other | $ 300,000,000 |  |  |  |  |  |  |  |  |  |  |
Line of Credit [Member] |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Business Combination, Consideration Transferred, Other | $ 162,000,000 |  |  |  |  |  |  |  |  |  |  |
Equity Method Investments [Member] | Post [Member] [Domain] |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Number Of Units Acquired In Real Estate Property | Communities | 269 |  |  |  |  |  |  |  |  |  |  |
Development Portfolio [Member] | Post [Member] [Domain] |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Number Of Units Acquired In Real Estate Property | Communities | 2,262 |  |  |  |  |  |  |  |  |  |  |
Parent Company [Member] |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Noncontrolling Interest in Joint Ventures |  | $ 2,306,000 |  |  |  | $ 2,306,000 |  |  |  | $ 2,306,000 | 2,306,000 |
Total operating revenues |  | $ 382,738,000 | $ 384,550,000 | $ 382,791,000 | $ 378,908,000 | $ 307,198,000 | $ 276,898,000 | $ 272,236,000 | $ 269,016,000 | 1,528,987,000 | 1,125,348,000 | $ 1,042,779,000
Business Combination, Merger and Integration Related Expenses |  |  |  |  |  |  |  |  |  | $ 19,990,000 | $ 40,823,000 | $ 0
Preferred Stock, Shares Outstanding | shares |  | 867,846 |  |  |  | 867,846 |  |  |  | 867,846 | 867,846 |
Parent Company [Member] | Post [Member] [Domain] |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Number of Apartment Communities Acquired in Real Estate Property | Communities | 61 |  |  |  |  |  |  |  |  |  |  |
Number Of Units Acquired In Real Estate Property | Communities | 24,138 |  |  |  |  |  |  |  |  |  |  |
Number of Commercial Properties Acquired in Real Estate Property | properties | 4 |  |  |  |  |  |  |  |  |  |  |
Acquired properties, purchase price | $ (4,006,586,000) |  |  |  |  |  |  |  |  |  |  |
Share Price | $ / shares | $ 91.41 |  |  |  |  |  |  |  |  |  |  |
Stock Issued During Period, Shares, Acquisitions | shares | 38,000,000 |  |  |  |  |  |  |  |  |  |  |
Parent Company [Member] | Commercial | Post [Member] [Domain] |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Square footage of real estate property (square foot) | ft² | 232 |  |  |  |  |  |  |  |  |  |  |
Noncontrolling Interest |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Stock Issued During Period, Shares, Acquisitions | shares | 100,000 |  |  |  |  |  |  |  |  |  |  |
Business Combination, Separately Recognized Transactions [Domain] |  |  |  |  |  |  |  |  |  |  |  |
Business Acquisition [Line Items] |  |  |  |  |  |  |  |  |  |  |  |
Business Combination, Merger and Integration Related Expenses |  |  |  |  |  |  |  |  |  | $ 20,000,000 |  |

X
- Definition Business Acquisition, Cost of Entity Acquired, Purchase Price + References No definition available. + Details
Name: | maa_BusinessAcquisitionCostofEntityAcquiredPurchasePrice
Namespace Prefix: | maa_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Business Combination, Merger and Integration Related Expenses + References No definition available. + Details
Name: | maa_BusinessCombinationMergerandIntegrationRelatedExpenses
Namespace Prefix: | maa_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Business Combinations, Other Consideration + References No definition available. + Details
Name: | maa_BusinessCombinationsOtherConsideration
Namespace Prefix: | maa_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Number of Units Acquired in Real Estate Property + References No definition available. + Details
Name: | maa_NumberOfUnitsAcquiredInRealEstateProperty
Namespace Prefix: | maa_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of Apartment Communities Acquired in Real Estate Property + References No definition available. + Details
Name: | maa_NumberofApartmentCommunitiesAcquiredinRealEstateProperty
Namespace Prefix: | maa_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Number of Commercial Properties Acquired in Real Estate Property + References No definition available. + Details
Name: | maa_NumberofCommercialPropertiesAcquiredinRealEstateProperty
Namespace Prefix: | maa_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Area of a real estate property. + References No definition available. + Details
Name: | us-gaap_AreaOfRealEstateProperty
Namespace Prefix: | us-gaap_
Data Type: | num:areaItemType
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_BusinessAcquisitionLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of tangible or intangible assets, including a business or subsidiary of the acquirer transferred by the entity to the former owners of the acquiree. Excludes cash. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 30 -Section 50 -Paragraph 1 -Subparagraph (b)(2) -URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479 + Details
Name: | us-gaap_BusinessCombinationConsiderationTransferredOther1
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Fair value as of the balance sheet date of the embedded derivative or group of embedded derivatives classified as an asset. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 10 -Section 50 -Paragraph 4B -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624163-113959 + Details
Name: | us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeAsset
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Fair value portion of shares that an entity is required to redeem for cash or other assets at a fixed or determinable date or upon the occurrence of an event. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 480 -SubTopic 10 -Section 25 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=6939902&loc=d3e21216-110875 + Details
Name: | us-gaap_MandatorilyRedeemablePreferredStockFairValueDisclosure
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Carrying amount of the equity interests owned by noncontrolling shareholders, partners, or other equity holders in joint ventures included in the entity's consolidated financial statements. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 810 -SubTopic 10 -Section 45 -Paragraph 16 -URI http://asc.fasb.org/extlink&oid=96868048&loc=SL4568740-111683 + Details
Name: | us-gaap_MinorityInterestInJointVentures
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Aggregate share number for all nonredeemable preferred stock (or preferred stock redeemable solely at the option of the issuer) held by stockholders. Does not include preferred shares that have been repurchased. + 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(28)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_PreferredStockSharesOutstanding
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- 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
Name: | us-gaap_Revenues
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Price of a single share of a number of saleable stocks of a company. + References No definition available. + Details
Name: | us-gaap_SharePrice
Namespace Prefix: | us-gaap_
Data Type: | num:perShareItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of shares of stock issued during the period pursuant to acquisitions. + 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(28)) -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(29)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 + Details
Name: | us-gaap_StockIssuedDuringPeriodSharesAcquisitions
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=us-gaap_RedeemablePreferredStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=us-gaap_UnsecuredDebtMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=us-gaap_LineOfCreditMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=us-gaap_EquityMethodInvestmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=maa_PostMemberDomain
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=maa_DevelopmentPortfolioMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ConsolidatedEntitiesAxis=us-gaap_ParentCompanyMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_InvestmentTypeAxis=maa_CommercialMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PartnerTypeOfPartnersCapitalAccountAxis=us-gaap_NoncontrollingInterestMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_IncomeStatementLocationAxis=us-gaap_BusinessCombinationSeparatelyRecognizedTransactionsDomain
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |