Partners' Capital of Mid-America Apartments, L.P.	6 Months Ended
Jun. 30, 2018
Partners' Capital of Mid-America Apartments, L.P. [Abstract]
Partners' Capital Notes Disclosure [Text Block]	Partners' Capital of MAALP Interests in MAALP are represented by OP Units. As of June 30, 2018, there were 117,943,960 OP Units outstanding, 113,808,292 or 96.5% of which represent Class B Common Units (Common Units issued to or held by MAALP's general partner or any of its subsidiaries) and which were owned by MAA, MAALP's general partner. The remaining 4,135,668 OP Units were Class A Common Units owned by Class A Limited Partners. As of June 30, 2017, there were 117,823,412 OP Units outstanding, 113,607,734 or 96.4% of which were owned by MAA and 4,215,678 of which were owned by the Class A Limited Partners. MAA, as the sole general partner of MAALP, has full, complete and exclusive discretion to manage and control the business of the Operating Partnership subject to the restrictions specifically contained within MAALP's agreement of limited partnership, or the Partnership Agreement. Unless otherwise stated in the Partnership Agreement, this power includes, but is not limited to, acquiring, leasing, or disposing of any real property; constructing buildings and making other improvements to properties owned; borrowing money, modifying or extinguishing current borrowings, issuing evidence of indebtedness, and securing such indebtedness by mortgage, deed of trust, pledge or other lien on the Operating Partnership's assets; and distribution of Operating Partnership cash or other assets in accordance with the Partnership Agreement. MAA can generally, at its sole discretion, issue and redeem OP Units and determine the consideration to be received or the redemption price to be paid, as applicable. The general partner may delegate these and other powers granted if the general partner remains in supervision of the designee. Under the Partnership Agreement, the Operating Partnership may issue Class A Common Units and Class B Common Units. Class A Common Units are any OP Units other than Class B Common Units, while Class B Common Units are those issued to or held by MAALP's general partner or any of its subsidiaries. In general, the limited partners do not have the power to participate in the management or control of the Operating Partnership's business except in limited circumstances including changes in the general partner and protective rights if the general partner acts outside of the provisions provided in the Partnership Agreement. The transferability of Class A Common Units is also limited by the Partnership Agreement. Net income (after allocations to preferred ownership interests) is allocated to the general partner and limited partners based on their respective ownership percentages of the Operating Partnership. Issuance or redemption of additional Class A Common Units or Class B Common Units changes the relative ownership percentage of the partners. The issuance of Class B Common Units generally occurs when MAA issues common stock and the proceeds from that issuance are contributed to the Operating Partnership in exchange for the issuance to MAA of a number of OP Units equal to the number of shares of common stock issued. Likewise, if MAA repurchases or redeems outstanding shares of common stock, the Operating Partnership generally redeems an equal number of Class B Common Units with similar terms held by MAA for a redemption price equal to the purchase price of those shares of common stock. At each reporting period, the allocation between general partner capital and limited partner capital is adjusted to account for the change in the respective percentage ownership of the underlying capital of the Operating Partnership. Holders of the Class A Common Units may require MAA to redeem their Class A Common Units, in which case MAA may, at its option, pay the redemption price either in cash (in an amount per Class A Common Unit equal, in general, to the average closing price of MAA's common stock on the NYSE over a specified period prior to the redemption date) or by delivering one share of MAA common stock (subject to adjustment under specified circumstances) for each Class A Common Unit so redeemed. At June 30, 2018, a total of 4,135,668 Class A Common Units were outstanding and redeemable for 4,135,668 shares of MAA common stock, with an approximate value of $416.3 million, based on the closing price of MAA’s common stock on June 29, 2018 of $100.67 per share. At June 30, 2017, a total of 4,215,678 Class A Common Units were outstanding and redeemable for 4,215,678 shares of MAA common stock, with an approximate value of $444.2 million, based on the closing price of MAA’s common stock on June 30, 2017 of $105.38 per share. The Operating Partnership pays the same per unit distributions in respect to the OP Units as the per share dividends MAA pays in respect to its common stock. As of June 30, 2018, the Operating Partnership had one outstanding series of cumulative redeemable preferred units, or the MAALP Series I Preferred Units. The MAALP Series I Preferred Units have the same characteristics as the MAA Series I preferred stock described in Note 8. As of June 30, 2018, 867,846 units of the MAALP Series I Preferred Units were outstanding.

Partners' Capital of MAALP

Interests in MAALP are represented by OP Units. As of June 30, 2018, there were 117,943,960 OP Units outstanding, 113,808,292 or 96.5% of which represent Class B Common Units (Common Units issued to or held by MAALP's general partner or any of its subsidiaries) and which were owned by MAA, MAALP's general partner. The remaining 4,135,668 OP Units were Class A Common Units owned by Class A Limited Partners. As of June 30, 2017, there were 117,823,412 OP Units outstanding, 113,607,734 or 96.4% of which were owned by MAA and 4,215,678 of which were owned by the Class A Limited Partners.

MAA, as the sole general partner of MAALP, has full, complete and exclusive discretion to manage and control the business of the Operating Partnership subject to the restrictions specifically contained within MAALP's agreement of limited partnership, or the Partnership Agreement. Unless otherwise stated in the Partnership Agreement, this power includes, but is not limited to, acquiring, leasing, or disposing of any real property; constructing buildings and making other improvements to properties owned; borrowing money, modifying or extinguishing current borrowings, issuing evidence of indebtedness, and securing such indebtedness by mortgage, deed of trust, pledge or other lien on the Operating Partnership's assets; and distribution of Operating Partnership cash or other assets in accordance with the Partnership Agreement. MAA can generally, at its sole discretion, issue and redeem OP Units and determine the consideration to be received or the redemption price to be paid, as applicable. The general partner may delegate these and other powers granted if the general partner remains in supervision of the designee.

Under the Partnership Agreement, the Operating Partnership may issue Class A Common Units and Class B Common Units. Class A Common Units are any OP Units other than Class B Common Units, while Class B Common Units are those issued to or held by MAALP's general partner or any of its subsidiaries. In general, the limited partners do not have the power to participate in the management or control of the Operating Partnership's business except in limited circumstances including changes in the general partner and protective rights if the general partner acts outside of the provisions provided in the Partnership Agreement. The transferability of Class A Common Units is also limited by the Partnership Agreement.

Net income (after allocations to preferred ownership interests) is allocated to the general partner and limited partners based on their respective ownership percentages of the Operating Partnership. Issuance or redemption of additional Class A Common Units or Class B Common Units changes the relative ownership percentage of the partners. The issuance of Class B Common Units generally occurs when MAA issues common stock and the proceeds from that issuance are contributed to the Operating Partnership in exchange for the issuance to MAA of a number of OP Units equal to the number of shares of common stock issued. Likewise, if MAA repurchases or redeems outstanding shares of common stock, the Operating Partnership generally redeems an equal number of Class B Common Units with similar terms held by MAA for a redemption price equal to the purchase price of those shares of common stock. At each reporting period, the allocation between general partner capital and limited partner capital is adjusted to account for the change in the respective percentage ownership of the underlying capital of the Operating Partnership. Holders of the Class A Common Units may require MAA to redeem their Class A Common Units, in which case MAA may, at its option, pay the redemption price either in cash (in an amount per Class A Common Unit equal, in general, to the average closing price of MAA's common stock on the NYSE over a specified period prior to the redemption date) or by delivering one share of MAA common stock (subject to adjustment under specified circumstances) for each Class A Common Unit so redeemed.

At June 30, 2018, a total of 4,135,668 Class A Common Units were outstanding and redeemable for 4,135,668 shares of MAA common stock, with an approximate value of $416.3 million, based on the closing price of MAA’s common stock on June 29, 2018 of $100.67 per share. At June 30, 2017, a total of 4,215,678 Class A Common Units were outstanding and redeemable for 4,215,678 shares of MAA common stock, with an approximate value of $444.2 million, based on the closing price of MAA’s common stock on June 30, 2017 of $105.38 per share. The Operating Partnership pays the same per unit distributions in respect to the OP Units as the per share dividends MAA pays in respect to its common stock.

As of June 30, 2018, the Operating Partnership had one outstanding series of cumulative redeemable preferred units, or the MAALP Series I Preferred Units. The MAALP Series I Preferred Units have the same characteristics as the MAA Series I preferred stock described in Note 8. As of June 30, 2018, 867,846 units of the MAALP Series I Preferred Units were outstanding.