Organization (Details) (USD $) In Millions, except Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2013 Apartment Building Project	Dec. 31, 2012
Organization [Abstract]
General partner ownership interest (in hundredths)	94.60%
Limited partners ownership interest (in hundredths)	5.40%
Operating Partnership units outstanding (in shares)	2,149,802	2,122,381
Redemption value of Operating Partnership units outstanding	$ 308.5	$ 311.2
Number of apartment communities owned	164
Apartment units owned (in units)	34,079
Ownership interests, number of commercial buildings	4
Ownership interests, number of active development projects	11
BRE Properties, Inc. [Member]
Schedule of Mergers [Line Items]
Common shares conversion ratio in connection with merger	0.2971
Share price (in dollars per share)	$ 12.33
Bridge loan	$ 1,000.0
Number of days bridge loan facility is structured	364 days