Legal Proceedings	6 Months Ended
Jun. 30, 2018
Disclosure Text Block [Abstract]
Legal Matters and Contingencies [Text Block]	Legal Proceedings In September 2010, the United States Department of Justice, or DOJ, filed suit against Post Properties (and by virtue of the merger with Post Properties, MAA) in the United States District Court for the District of Columbia alleging that certain of Post Properties’ apartments violated accessibility requirements of the Fair Housing Act, or FHA, and the Americans with Disabilities Act of 1990, or ADA. The DOJ is seeking, among other things, an injunction against MAA, requiring MAA to retrofit the properties and comply with FHA and ADA standards in future design and construction, as well as monetary damages and civil penalties. No trial date has been set. In December 2017, a non-profit civil rights organization filed suit against MAA and the Operating Partnership in the United States District Court for the District of Columbia. The suit alleges the Company maintained and enforced a criminal records screening policy at certain of its apartment communities, all of which are apartments acquired in the merger with Post Properties, which violates the FHA. The suit seeks injunctive relief, actual and punitive damages and attorneys' fees and costs. The Company is subject to various other legal proceedings and claims that arise in the ordinary course of its business operations. Matters which arise out of allegations of bodily injury, property damage and employment practices are generally covered by insurance. While the resolution of these other matters cannot be predicted with certainty, management does not currently believe such matters, either individually or in the aggregate, will have a material adverse effect on the Company's financial position, results of operations or cash flows. Loss Contingencies The outcomes of claims, disputes and legal proceedings are subject to significant uncertainty. The Company records an accrual for loss contingencies when a loss is probable and the amount of the loss can be reasonably estimated. Management reviews these accruals quarterly and makes revisions based on changes in facts and circumstances. When a loss contingency is not both probable and reasonably estimable, management does not accrue the loss. However, if the loss (or an additional loss in excess of the accrual) is at least a reasonable possibility and material, then management discloses a reasonable estimate of the possible loss, or range of loss, if such reasonable estimate can be made. If the Company cannot make a reasonable estimate of the possible loss, or range of loss, then a statement to that effect is disclosed. The assessment of whether a loss is probable or a reasonable possibility, and whether the loss or range of loss is reasonably estimable, often involves a series of complex judgments about future events. Among the factors considered in this assessment, are the nature of existing legal proceedings and claims, the asserted or possible damages or loss contingency (if reasonably estimable), the progress of the matter, existing law and precedent, the opinions or views of legal counsel and other advisers, management's experience in similar matters, the facts available to management at the time of assessment, and how the Company intends to respond, or has responded, to the proceeding or claim. Management's assessment of these factors may change over time as individual proceedings or claims progress. For matters where management is not currently able to reasonably estimate a range of reasonably possible loss, the factors that have contributed to this determination include the following: (i) the damages sought are indeterminate; (ii) the proceedings are in the early stages; (iii) the matters involve novel or unsettled legal theories or a large or uncertain number of actual or potential cases or parties; and/or (iv) discussions with the parties in matters that are expected ultimately to be resolved through negotiation and settlement have not reached the point where management believes a reasonable estimate of loss, or range of loss, can be made. The Company believes that there is considerable uncertainty regarding the timing or ultimate resolution of such matters, including a possible eventual loss or business impact, if any. As of June 30, 2018 and December 31, 2017, the Company's accrual for loss contingencies was $29.0 million and $32.1 million in the aggregate, respectively. The loss contingencies are presented in "Accrued expenses and other liabilities" in the accompanying Condensed Consolidated Balance Sheets.

Legal Proceedings

In September 2010, the United States Department of Justice, or DOJ, filed suit against Post Properties (and by virtue of the merger with Post Properties, MAA) in the United States District Court for the District of Columbia alleging that certain of Post Properties’ apartments violated accessibility requirements of the Fair Housing Act, or FHA, and the Americans with Disabilities Act of 1990, or ADA. The DOJ is seeking, among other things, an injunction against MAA, requiring MAA to retrofit the properties and comply with FHA and ADA standards in future design and construction, as well as monetary damages and civil penalties. No trial date has been set.

In December 2017, a non-profit civil rights organization filed suit against MAA and the Operating Partnership in the United States District Court for the District of Columbia. The suit alleges the Company maintained and enforced a criminal records screening policy at certain of its apartment communities, all of which are apartments acquired in the merger with Post Properties, which violates the FHA. The suit seeks injunctive relief, actual and punitive damages and attorneys' fees and costs.

The Company is subject to various other legal proceedings and claims that arise in the ordinary course of its business operations. Matters which arise out of allegations of bodily injury, property damage and employment practices are generally covered by insurance. While the resolution of these other matters cannot be predicted with certainty, management does not currently believe such matters, either individually or in the aggregate, will have a material adverse effect on the Company's financial position, results of operations or cash flows.

Loss Contingencies

The outcomes of claims, disputes and legal proceedings are subject to significant uncertainty. The Company records an accrual for loss contingencies when a loss is probable and the amount of the loss can be reasonably estimated. Management reviews these accruals quarterly and makes revisions based on changes in facts and circumstances. When a loss contingency is not both probable and reasonably estimable, management does not accrue the loss. However, if the loss (or an additional loss in excess of the accrual) is at least a reasonable possibility and material, then management discloses a reasonable estimate of the possible loss, or range of loss, if such reasonable estimate can be made. If the Company cannot make a reasonable estimate of the possible loss, or range of loss, then a statement to that effect is disclosed.

The assessment of whether a loss is probable or a reasonable possibility, and whether the loss or range of loss is reasonably estimable, often involves a series of complex judgments about future events. Among the factors considered in this assessment, are the nature of existing legal proceedings and claims, the asserted or possible damages or loss contingency (if reasonably estimable), the progress of the matter, existing law and precedent, the opinions or views of legal counsel and other advisers, management's experience in similar matters, the facts available to management at the time of assessment, and how the Company intends to respond, or has responded, to the proceeding or claim. Management's assessment of these factors may change over time as individual proceedings or claims progress. For matters where management is not currently able to reasonably estimate a range of reasonably possible loss, the factors that have contributed to this determination include the following: (i) the damages sought are indeterminate; (ii) the proceedings are in the early stages; (iii) the matters involve novel or unsettled legal theories or a large or uncertain number of actual or potential cases or parties; and/or (iv) discussions with the parties in matters that are expected ultimately to be resolved through negotiation and settlement have not reached the point where management believes a reasonable estimate of loss, or range of loss, can be made. The Company believes that there is considerable uncertainty regarding the timing or ultimate resolution of such matters, including a possible eventual loss or business impact, if any.

As of June 30, 2018 and December 31, 2017, the Company's accrual for loss contingencies was $29.0 million and $32.1 million in the aggregate, respectively. The loss contingencies are presented in "Accrued expenses and other liabilities" in the accompanying Condensed Consolidated Balance Sheets.