Employee Benefit Plans (Details) (USD $)	12 Months Ended										12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 2013 Stock Option And Incentive Plan 1994	Dec. 31, 2013 Employee Stock Ownership Plan ESOP Plan	Dec. 31, 2008 Initial Public Offering	Dec. 31, 2013 Outside Directors	Dec. 31, 2012 Outside Directors	Dec. 31, 2011 Outside Directors	Dec. 31, 2010 Outside Directors	Dec. 31, 2013 Nonqualified Deferred Compensation Plan installment	Dec. 31, 2012 Nonqualified Deferred Compensation Plan	Dec. 31, 2011 Nonqualified Deferred Compensation Plan
Defined Benefit Plan Disclosure
Employer contribution for defined contribution plan	$ 675,000	$ 668,000	$ 597,000
Deferred compensation expense											46,000	45,000	51,000
Number of annual installments of deferred compensation (installment)											2
Number of days after departure from board of directors for payment of deferred compensation (days)											90 days
Number of deferred common stock (shares)							7,173	5,549	5,328
Weighted-average grant date fair values of deferred common stock (dollars per share)							$ 66.77	$ 66.12	$ 64.55
Directors Deferred Compensation Plan, cash payout liability										78,000
Employee Stock Ownership Plan, service period eligible to participate (years)					1 year
Participants vesting percentage after three years of continuous service (percent)					100.00%
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period					3 years
Contribution to Employee Stock Ownership Plan, common stock (shares)						22,500
Employee Stock Ownership Plan, common stock, shares outstanding (shares)	186,872
Employee Stock Ownership Plan, common stock, fair value	$ 11,400,000
Description of bonus				Under the terms of the supplemental bonus agreements, MAA will pay bonuses to these employees equal to 3% of the original note balance on each anniversary date of the advance, limited to 15% of the aggregate purchase price of the shares and units.