Partners' Capital of Mid-America Apartments, L.P. (Details) - USD ($) $ / shares in Units, $ in Millions	6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014
Schedule of Capital Structure [Line Items]
Operating partnership units outstanding	79,561,396	79,401,933
General Partners' Capital Account, Units Outstanding	75,375,027	75,194,807
Limited Liability Company (LLC) or Limited Partnership (LP), Managing Member or General Partner, Ownership Interest	94.70%	94.70%
Limited Partners' Capital Account, Units Outstanding	4,186,369	4,207,126
Noncontrolling Interest [Member]
Schedule of Capital Structure [Line Items]
Common Shares Issuable Upon Conversion Of Convertible Stock	4,186,369	4,207,126
Limited Partners' Capital Account	$ 304.8	$ 307.3
Redeemable Capital Shares Par Or Stated Value Per Share	$ 72.81	$ 73.05