Partners' Capital of Mid-America Apartments, L.P. (Details) - USD ($) $ / shares in Units, $ in Millions	6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Mar. 31, 2015
Schedule of Capital Structure [Line Items]
Operating partnership units outstanding	79,683,089	79,561,396
General Partners' Capital Account, Units Outstanding	75,524,086	75,375,027
Limited Liability Company (LLC) or Limited Partnership (LP), Managing Member or General Partner, Ownership Interest	94.80%	94.70%
Limited Partners' Capital Account, Units Outstanding	4,159,003	4,186,369
Noncontrolling Interest [Member]
Schedule of Capital Structure [Line Items]
Common Shares Issuable Upon Conversion Of Convertible Stock	4,159,003	4,186,369
Limited Partners' Capital Account	$ 442.5		$ 304.8
Redeemable Capital Shares Par Or Stated Value Per Share	$ 106.40		$ 72.81