Shareholders' Equity of MAA - Additional Information (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Equity [Line Items]
Common stock, shares outstanding	114,408,949	114,279,662	114,373,727
Total common shares and operating partnership units outstanding	118,462,055	118,338,319
Proceeds from Stock Options Exercised, Net	$ 1.5	$ 0.1
At The Market Offering
Equity [Line Items]
Common stock shares sold	0	0
Remaining common stock to be issued	3,900,000
Maximum [Member] | At The Market Offering
Equity [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	4,000,000.0
Equity Option
Equity [Line Items]
Stock Issued During Period, Shares, New Issues	18,882	918
Noncontrolling Interest
Equity [Line Items]
Common Shares Issuable Upon Conversion Of Convertible Stock	4,053,106	4,058,657
Employee Stock Option
Equity [Line Items]
Common stock shares, outstanding option	963	19,845