Related Party Transactions (Details) (USD $)	1 Months Ended	3 Months Ended		9 Months Ended		1 Months Ended	3 Months Ended	0 Months Ended	3 Months Ended		9 Months Ended
	Oct. 31, 2014	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Jan. 31, 2013 Marcus and Millichamp Company TMMC Affiliate [Member]	Sep. 30, 2013 MMC [Member]	Jul. 31, 2014 Paragon Apartments [Member] Unit	Sep. 30, 2014 Reduction to General and Administrative Expenses [Member]	Sep. 30, 2013 Reduction to General and Administrative Expenses [Member]	Sep. 30, 2014 Reduction to General and Administrative Expenses [Member]	Sep. 30, 2013 Reduction to General and Administrative Expenses [Member]
Related Party Transaction [Line Items]
Management and other fees from affiliates including management, property management, development and redevelopment fees from co-investments, net of intercompany amounts eliminated by company		$ 4,100,000	$ 3,000,000	$ 11,700,000	$ 9,100,000				$ 1,700,000	$ 1,200,000	$ 4,900,000	$ 3,300,000
Preferred return on preferred equity investment, thereafter, maximum (in hundredths)							13.00%
Preferred return on preferred equity investment, thereafter, minimum (in hundredths)							9.00%
Maximum term extended (in years)							1 year
Income related to the restructured investment							400,000
Preferred equity interest investment in a related party entity						8,600,000
Short term bridge loan		9,100,000		9,100,000
Number of units								301
Cost of acquired entity	$ 180,000,000			$ 555,826,000	$ 0			$ 111,000,000