Shareholders' Equity of MAA - Additional Information (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Dec. 31, 2020
Equity [Line Items]
Common stock, shares outstanding	114,919,922	114,365,203	114,373,727
Total common shares and operating partnership units outstanding	118,538,877	118,423,860
Proceeds from Stock Options Exercised, Net	$ 1.5	$ 0.1
At The Market Offering [Member]
Equity [Line Items]
Common stock shares sold	0	0
Remaining common stock to be issued	3,900,000
Maximum [Member] | At The Market Offering [Member]
Equity [Line Items]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized	4,000,000.0
Equity Option [Member]
Equity [Line Items]
Stock Issued During Period, Shares, New Issues	18,882	918
Noncontrolling Interest [Member]
Equity [Line Items]
Common Shares Issuable Upon Conversion Of Convertible Stock	3,618,955	4,058,657
Employee Stock Option [Member]
Equity [Line Items]
Common stock shares, outstanding option	963	19,845