Debt Instrument, Average Interest Rate

No definition available.

Name:	maa_DebtInstrumentAverageInterestRate
Namespace Prefix:	maa_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Debt Renewal Period

+ References

No definition available.

+ Details

Name:	maa_DebtRenewalPeriod
Namespace Prefix:	maa_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

Name:	us-gaap_DebtInstrumentBasisSpreadOnVariableRate1
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Face (par) amount of debt instrument at time of issuance.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 55
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 835
-SubTopic 30
-Section 45
-Paragraph 2
-URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399

+ Details

Name:	us-gaap_DebtInstrumentFaceAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

+ Details

Name:	us-gaap_DebtInstrumentInterestRateEffectivePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

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

- Definition

Description of the maturity date of the debt instrument including whether the debt matures serially and, if so, a brief description of the serial maturities.

+ References

+ Details

Name:	us-gaap_DebtInstrumentMaturityDateDescription
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

Name:	us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ 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(22))
-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 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

Name:	us-gaap_LineOfCredit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The fee, expressed as a percentage of the line of credit facility, for the line of credit facility regardless of whether the facility has been used.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityCommitmentFeePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

Name:	us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Reference 3: 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(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

+ Details

Name:	us-gaap_LongTermDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The interest rate applicable to the portion of the carrying amount of long-term borrowings outstanding as of the balance sheet date, including current maturities, which accrues interest at a set, unchanging rate.

+ References

+ Details

Name:	us-gaap_LongTermDebtPercentageBearingFixedInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

+ References

+ Details

Name:	us-gaap_LongTermDebtPercentageBearingVariableInterestRate
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Total carrying amount of mortgage loans as of the balance sheet date.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 205
-SubTopic 10
-Section S99
-Paragraph 6
-Subparagraph (SX 210.5-04.(c) Schedule IV)
-URI http://asc.fasb.org/extlink&oid=27047687&loc=d3e5864-122674

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 948
-SubTopic 310
-Section S99
-Paragraph 1
-Subparagraph (SX 210.12-29.6)
-URI http://asc.fasb.org/extlink&oid=6589523&loc=d3e617274-123014

+ Details

Name:	us-gaap_MortgageLoansOnRealEstate
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

Including the current and noncurrent portions, aggregate carrying amount of all types of notes payable, as of the balance sheet date, with initial maturities beyond one year or beyond the normal operating cycle, if longer.

+ 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(22))
-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 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

Name:	us-gaap_NotesPayable
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations.

+ References

No definition available.

+ Details

Name:	us-gaap_RepaymentsOfDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The cash outflow for a borrowing supported by a written promise to pay an obligation.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Glossary Financing Activities
-URI http://asc.fasb.org/extlink&oid=6513228

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=66902209&loc=d3e3291-108585

+ Details

Name:	us-gaap_RepaymentsOfNotesPayable
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Including the current and noncurrent portions, carrying value as of the balance sheet date of uncollateralized debt obligations (with maturities initially due after one year or beyond the operating cycle if longer).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(a)(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

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(22))
-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 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

Name:	us-gaap_UnsecuredDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_DebtInstrumentAxis=maa_ConventionalVariableRateDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=maa_CappedConventionalVariableRateDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=us-gaap_MortgagesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=maa_OtherThanConventionalVariableRateDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=maa_FixedRateSeniorNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_SecuredDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=us-gaap_FederalNationalMortgageAssociationCertificatesAndObligationsFNMAMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	maa_DebtInformationAxis=maa_VariableRateDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	maa_DebtInformationAxis=maa_FixedRateDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LongtermDebtTypeAxis=us-gaap_UnsecuredDebtMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=maa_WellsFargoTermLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=maa_USBankTermLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=maa_A500millionunsecuredrevolvingcreditfaciltiyMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=maa_KeyBankTermLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=us-gaap_IncomeNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=us-gaap_PrivatePlacementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=maa_A2011and2012SeniorNotesMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=maa_A750millionunsecuredrevolvingcreditfacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=maa_TermLoanMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_DebtInstrumentAxis=maa_WellsFargoandUSBankTermLoansMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=maa_FarmingtonVillageMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	dei_LegalEntityAxis=maa_ColonialGrandAtWilmingtonMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

Notes Payable - Additional Information (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Notes Payable	$ 3,434,157	$ 3,430,000
Debt Instrument, Interest Rate, Effective Percentage	3.60%	3.70%
Conventional Variable Rate Debt [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate	1.00%
Long-term Debt	$ 115,000
Capped Conventional Variable Rate Debt [Member]
Debt Instrument [Line Items]
Long-term Debt, Percentage Bearing Variable Interest, Percentage Rate	1.00%
Long-term Debt	$ 75,000
Mortgages [Member]
Debt Instrument [Line Items]
Repayments of Notes Payable	5,900
Other Than Conventional Variable Rate Debt [Member]
Debt Instrument [Line Items]
Long-term Debt	$ 1,000,000
Debt Instrument Average Interest Rate	4.00%
Fixed Rate Senior Notes [Member]
Debt Instrument [Line Items]
Unsecured notes payable	$ 2,000,000
Long-term Debt, Percentage Bearing Fixed Interest, Percentage Rate	3.80%
Secured Debt [Member]
Debt Instrument [Line Items]
Notes Payable	$ 1,238,168
Debt Instrument, Interest Rate, Effective Percentage	3.50%
Secured Debt [Member] \| Federal National Mortgage Association Certificates and Obligations (FNMA) [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.17%
Line of Credit Facility, Commitment Fee Percentage	0.62%
Line of Credit Facility, Amount Outstanding	$ 240,000
Line of Credit Facility, Maximum Borrowing Capacity	$ 240,000
Debt Renewal Period	90 days
Secured Debt [Member] \| Federal National Mortgage Association Certificates and Obligations (FNMA) [Member] \| Variable Rate Debt [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Effective Percentage	1.20%
Line of Credit Facility, Amount Outstanding	$ 190,000
Secured Debt [Member] \| Federal National Mortgage Association Certificates and Obligations (FNMA) [Member] \| Fixed Rate Debt
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Effective Percentage	4.70%
Line of Credit Facility, Amount Outstanding	$ 50,000
Secured Debt [Member] \| Mortgages [Member] \| Fixed Rate Debt
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Effective Percentage	4.00%
Mortgage Loans on Real Estate	$ 972,948
Unsecured Debt [Member]
Debt Instrument [Line Items]
Notes Payable	$ 2,195,989
Debt Instrument, Interest Rate, Effective Percentage	3.60%
Unsecured Debt [Member] \| Wells Fargo Term Loan [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 250,000
Unsecured Debt [Member] \| US Bank Term Loan [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 150,000
Unsecured Debt [Member] \| $500 million unsecured revolving credit faciltiy [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Effective Percentage	1.47%
Letters of Credit Outstanding, Amount	$ 3,300
Unsecured Debt [Member] \| $500 million unsecured revolving credit faciltiy [Member] \| Variable Rate Debt [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Effective Percentage	1.50%
Line of Credit Facility, Amount Outstanding	$ 205,000
Unsecured Debt [Member] \| KeyBank Term Loan [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	150,000
Unsecured Debt [Member] \| Public Income Notes [Member] \| Fixed Rate Debt
Debt Instrument [Line Items]
Debt Instrument, Face Amount	1,200,000
Unsecured Debt [Member] \| Private Placement [Member] \| Fixed Rate Debt
Debt Instrument [Line Items]
Debt Instrument, Face Amount	310,000
Unsecured Debt [Member] \| 2011 and 2012 Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	310,000
Unsecured Debt [Member] \| $750 million unsecured revolving credit facility [Member]
Debt Instrument [Line Items]
Line of Credit Facility, Amount Outstanding	205,000
Line of Credit Facility, Maximum Borrowing Capacity	750,000
Unsecured Debt [Member] \| Term Loan [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 550,000
Debt Instrument, Interest Rate, Effective Percentage	3.10%
Minimum [Member] \| Unsecured Debt [Member] \| Fixed Rate Debt
Debt Instrument [Line Items]
Debt Instrument, Maturity Date, Description	P5Y
Minimum [Member] \| Unsecured Debt [Member] \| $500 million unsecured revolving credit faciltiy [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.85%
Minimum [Member] \| Unsecured Debt [Member] \| KeyBank Term Loan [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.90%
Minimum [Member] \| Unsecured Debt [Member] \| Wells Fargo and US Bank Term Loans [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	0.90%
Maximum [Member] \| Unsecured Debt [Member] \| Fixed Rate Debt
Debt Instrument [Line Items]
Debt Instrument, Maturity Date, Description	P12Y
Maximum [Member] \| Unsecured Debt [Member] \| $500 million unsecured revolving credit faciltiy [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.55%
Line of Credit Facility, Maximum Borrowing Capacity	$ 1,500,000
Maximum [Member] \| Unsecured Debt [Member] \| KeyBank Term Loan [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.75%
Maximum [Member] \| Unsecured Debt [Member] \| Wells Fargo and US Bank Term Loans [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate	1.90%
Farmington Village [Member] \| Secured Debt [Member] \| Mortgages [Member] \| Variable Rate Debt [Member]
Debt Instrument [Line Items]
Repayments of Debt	$ 13,400
Colonial Grand at Wilmington [Member] \| Secured Debt [Member] \| Mortgages [Member] \| Variable Rate Debt [Member]
Debt Instrument [Line Items]
Repayments of Debt	$ 20,200