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Shareholders' Equity of MAA - Additional Information (Details) - USD ($) $ in Millions | 9 Months Ended |
--- | --- | ---
Sep. 30, 2019 | Sep. 30, 2018 | Dec. 31, 2018
Equity [Line Items] |  |  |
Common stock, shares outstanding | 114,065,859 | 113,838,139 | 113,844,267
Total common shares and operating partnership units outstanding | 118,140,136 | 117,952,415 |
Proceeds from Stock Options Exercised, Net | $ 1.0 | $ 0.9 |
Equity Option [Member] |  |  |
Equity [Line Items] |  |  |
Stock Issued During Period, Shares, New Issues | 24,256 | 17,823 |
Noncontrolling Interest |  |  |
Equity [Line Items] |  |  |
Common Shares Issuable Upon Conversion Of Convertible Stock | 4,074,277 | 4,114,276 |
Employee Stock Option [Member] |  |  |
Equity [Line Items] |  |  |
Common stock shares, outstanding option | 45,390 | 90,615 |

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