Noncontrolling Interests (Details) (USD $)	12 Months Ended							3 Months Ended	12 Months Ended
	Dec. 31, 2013 Units	Dec. 31, 2012	Dec. 31, 2011	Dec. 31, 1998 Communities	Oct. 30, 2005 Communities	Dec. 31, 2013 7001 Arlington Road [Member] acre sqft	Mar. 31, 2012 7001 Arlington Road [Member] Units	Mar. 31, 2013 Vista Germantown [Member]	Dec. 31, 2013 Vista Germantown [Member] Communities	Dec. 31, 2012 Vista Germantown [Member]	Sep. 24, 2010 Vista Germantown [Member]
Noncontrolling Interest [Line Items]
Number of apartment communities acquired				2
Number of apartment communities sold					1
Opertating partnership units issued				522,032
Units redeemed	74,083	0	0
Operating partnership redemption	$ 1,393,000	$ 0	$ 0					$ 4,500,000
Partners' capital account, units	0
Equity interest in partnership						97.00%			100.00%	90.00%	90.00%
Area of land						2.5
Cost of land							12,200,000
Apartment units owned	13,676						140		242
Area of real estate property to be developed						7,000
Contributions in aid of construction									$ 9,400,000		$ 9,400,000
Redeemed ownership percentage									10.00%