Investments in Real Estate (Details)	12 Months Ended
	Dec. 31, 2015 USD ($) Number Interger
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Number of Units | Number	1,824
Pro Forma Average Rent	$ 1,887	[1]
Alexan CityCentre, Houston, TX [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Number of Units | Number	340
Initial Occupancy	1Q 2017
Final Units to be Delivered	4Q 2017
Pro Forma Average Rent	$ 2,144	[1]
Alexan Southside Place, Houston, TX [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Number of Units | Number	269
Initial Occupancy	3Q 2017
Final Units to be Delivered	2Q 2018
Pro Forma Average Rent	$ 2,019	[1]
Cheshire Bridge, Atlanta, GA [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Number of Units | Number	285
Initial Occupancy	1Q 2017
Final Units to be Delivered	3Q 2017
Pro Forma Average Rent	$ 1,559	[1]
Domain, Garland, TX [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Number of Units | Number	301
Initial Occupancy	2Q 2017
Final Units to be Delivered	2Q 2018
Pro Forma Average Rent	$ 1,425	[1]
Flagler Village Ft Lauderdale FL [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Number of Units | Number	384
Initial Occupancy	2Q 2018
Final Units to be Delivered	1Q 2019
Pro Forma Average Rent	$ 2,481	[1]
Lake Boone Trail Raleigh NC [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Number of Units | Number	245
Initial Occupancy	1Q 2018
Final Units to be Delivered	3Q 2018
Pro Forma Average Rent	$ 1,402	[1]
MDA Apartments, Chicago, IL [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Number of Units	190
Pro Forma Average Rent	$ 2,251	[2]
Date Build/Renovated	2006	[3]
Ownership Interest	35.30%
% Occupied	92.00%	[4]
Enders at Baldwin Park, Orlando, FL [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Number of Units	220
Pro Forma Average Rent	$ 1,595	[2]
Date Build/Renovated	2003	[3]
Ownership Interest	89.50%
% Occupied	97.00%	[4]
Whetstone Durham N C [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Number of Units	204
Pro Forma Average Rent	$ 1,325	[2]
Date Build/Renovated	2015	[3]
Ownership Interest	(6.00%)	[5]
% Occupied	73.00%	[4]
Park Kingston, Charlotte [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Number of Units	168	[6]
Pro Forma Average Rent	$ 1,151	[2],[6]
Date Build/Renovated	2015	[3],[6]
Ownership Interest	96.40%	[6]
% Occupied	91.00%	[4],[6]
Lansbrook Village, Palm Harbor, FL [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Number of Units	602
Pro Forma Average Rent	$ 1,182	[2]
Date Build/Renovated	2004	[3]
Ownership Interest	90.00%
% Occupied	93.00%	[4]
ARIUM Grandewood, Orlando, FL [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Number of Units	306	[7]
Pro Forma Average Rent	$ 1,184	[2],[7]
Date Build/Renovated	2005	[3],[7]
Ownership Interest	95.00%	[7]
% Occupied	97.00%	[4],[7]
Village Green of Ann Arbor, Ann Arbor, MI [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Number of Units	520
Pro Forma Average Rent	$ 1,167	[2]
Date Build/Renovated	2013	[3]
Ownership Interest	48.60%
% Occupied	91.00%	[4]
Fox Hill, Austin, TX [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Number of Units	288
Pro Forma Average Rent	$ 1,145	[2]
Date Build/Renovated	2010	[3]
Ownership Interest	94.60%
% Occupied	98.00%	[4]
Springhouse at Newport News, Newport News, VA [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Number of Units	432
Pro Forma Average Rent	$ 837	[2]
Date Build/Renovated	1985	[3]
Ownership Interest	75.00%
% Occupied	93.00%	[4]
Average [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Number of Units	4,625
Pro Forma Average Rent	$ 1,200
% Occupied	93.00%	[4]
EOS Orlando F L [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Number of Units	296
Pro Forma Average Rent	$ 1,211	[2]
Date Build/Renovated	2015	[3]
Ownership Interest	(6.00%)	[5]
% Occupied	51.00%	[4]
ARIUM Palms Orlando, FL [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Number of Units	252
Pro Forma Average Rent	$ 1,161	[2]
Date Build/Renovated	2008	[3]
Ownership Interest	95.00%
% Occupied	94.00%	[4]
Ashton I Charlotte, NC [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Number of Units | Interger	473	[8]
Pro Forma Average Rent	$ 968	[2],[8]
Date Build/Renovated	2012/2015	[3],[8]
Ownership Interest	100.00%	[8]
% Occupied	92.00%	[4],[8]
Sorrel Frisco TX [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Number of Units | Interger	352	[9]
Pro Forma Average Rent	$ 1,288	[2],[9]
Date Build/Renovated	2015	[3],[9]
Ownership Interest	95.00%	[9]
% Occupied	77.00%	[4],[9]
Sovereign Fort Worth TX [Member]
SEC Schedule III, Real Estate and Accumulated Depreciation [Line Items]
Number of Units | Interger	322
Pro Forma Average Rent	$ 1,265	[2]
Date Build/Renovated	2015	[3]
Ownership Interest	95.00%
% Occupied	90.00%	[4]

[1] Represents the average pro forma effective monthly rent per occupied unit for all expected occupied units upon stabilization.

[2] Represents the average effective monthly rent per occupied unit for all occupied units for the three months ended December 31, 2015. The average rent for Whetstone, EOS and Sorrel, which are still in lease-up, is pro forma based on underwriting. Total concessions for the three months ended December 31, 2015 amounted to approximately $0.3 million.

[3] Represents date of last significant renovation or year built if there were no renovations.

[4] Percent occupied is calculated as (i) the number of units occupied as of December 31, 2015, divided by (ii) total number of units, expressed as a percentage, excluding Whetstone, EOS and Sorrel, which are still in lease-up.

[5] EOS and Whetstone are currently preferred equity investments providing a stated investment return and both properties are in lease-up and average actual rents were $1,165 and $1,091, respectively, net of upfront lease-up concessions.

[6] Park & Kingston is comprised of Park & Kingston and Park & Kingston II. We own 96.0% of 151 units of Park & Kingston acquired in March 2015 and 100.0% of 15 units of Park & Kingston II acquired in November 2015, for a combined ownership of 96.4%.

[7] ARIUM Grandewood was formerly called ARIUM Grande Lakes.

[8] Ashton Reserve is comprised of Ashton I and Ashton II.

[9] Sorrel is in lease-up and average actual rents were $1,272, net of up-front lease-up concessions.