Acquisition, Development, and Disposition Activity Purchase Price Allocation (Details)		3 Months Ended		6 Months Ended
		Jun. 30, 2015 USD ($) Units	Jun. 30, 2014 USD ($)	Jun. 30, 2015 USD ($) Units	Jun. 30, 2014 USD ($)	Dec. 31, 2014 USD ($)	Sep. 30, 2013 USD ($)
Business Acquisition [Line Items]
Apartment units owned		882		882
Development costs		$ 133,000	$ 198,000	$ 332,000	$ 528,000
Land		6,953,000	8,140,000	6,953,000	8,140,000
Buildings and improvements		71,664,000	36,044,000	71,664,000	36,044,000
Furniture and fixtures		1,270,000	468,000	1,270,000	468,000
Existing leases (Other assets)		463,000	$ 423,000	463,000	$ 423,000
Total		80,350,000		80,350,000			$ 45,075,000
Construction in progress		47,886,000		47,886,000		$ 73,581,000
Construction loan		$ 0		0
1160 Hammond [Member]
Business Acquisition [Line Items]
Purchase price				$ 80,400,000
Apartment units owned | Units		345		345
Varela [Member]
Business Acquisition [Line Items]
Purchase price				$ 79,450
Apartment units owned | Units		350		350
Current Development [Member]
Business Acquisition [Line Items]
Apartment units owned | Units		564		564
Development costs	[1]			$ 187,112,000
Construction in progress		$ 165,758,000		165,758,000
Construction loan		$ 65,936,000		$ 65,936,000
Current Development [Member] | The Desmond on Wilshire [Member]
Business Acquisition [Line Items]
Apartment units owned | Units		175		175
Equity interest		100.00%		100.00%
Development costs	[1]			$ 77,800,000
Construction in progress		$ 57,540,000		57,540,000
Construction loan		$ 0		$ 0
Future Development [Member]
Business Acquisition [Line Items]
Apartment units owned | Units	[2]	533		533
Construction in progress		$ 38,321,000		$ 38,321,000
350 8th [Member] | Current Development [Member]
Business Acquisition [Line Items]
Purchase price				$ 46,600,000
Apartment units owned | Units		410		410
350 8th [Member] | Future Development [Member]
Business Acquisition [Line Items]
Apartment units owned | Units		410		410
Development costs	[3]			$ 245,000,000
Construction in progress		$ 117,003,000		117,003,000
Construction loan		$ 6,000		$ 6,000

[1] Total capital costs are calculated as if owned 100% by AEC and represent estimated costs for projects under development inclusive of all capitalized costs in accordance with GAAP. Based on current projections as of July 31, 2015.

[2] Based on current projections as of July 31, 2015.

[3] Total capital costs are calculated as if owned 100% by AEC and represent estimated costs for projects under development inclusive of all capitalized costs in accordance with GAAP. Based on current projections as of July 31, 2015.