Equity - Additional Information (Detail) $ / shares in Units, $ in Thousands											8 Months Ended	12 Months Ended
	Jan. 31, 2016 $ / shares	Jan. 07, 2016 USD ($)	Dec. 09, 2015 USD ($) shares	Jul. 10, 2015 shares	May. 05, 2015 USD ($)	Apr. 08, 2015 shares	Sep. 15, 2014 USD ($) shares	Aug. 15, 2014 shares	Mar. 31, 2014 shares	Jan. 17, 2014 shares	Dec. 31, 2013 shares	Dec. 31, 2015 USD ($) $ / shares shares	Dec. 31, 2014 USD ($) $ / shares shares	Dec. 31, 2013 USD ($) $ / shares shares
Class of Stock [Line Items]
Shares issued through public offering			3,450,000				5,750,000
Net proceeds from public offering | $			$ 35,100				$ 49,300					$ 46,462	$ 49,566	$ 203,245
Authorized capital shares of common stock												500,000,000	500,000,000
Authorized capital shares of preferred stock												100,000,000	100,000,000
Common Stock, Shares, Issued												30,076,359	25,022,701
Common Stock, Shares, Outstanding												30,076,359	25,022,701
Preferred stock issued												0	0
Preferred stock outstanding												0	0
Percentage of Operating Partnership held												65.60%	62.90%
Operating partnership units redemption ratio												1
Aggregate cash dividends and distributions, paid | $												$ 27,024	$ 22,096	$ 7,733
Cash dividend per share, declared | $ / shares												$ 0.68	$ 0.64	$ 0.40
Common Stock
Class of Stock [Line Items]
Shares issued through public offering											19,003,750	4,560,049	5,750,000
Common Stock, Shares, Outstanding											19,163,413	30,076,359	25,022,701	19,163,413
Aggregate cash dividends and distributions, paid | $		$ 5,100										$ 17,100	$ 13,200	$ 4,600
Columbus Village | Class B units
Class of Stock [Line Items]
Acquisition, common units/shares issued				1,000,000
Columbus Village | Class C units
Class of Stock [Line Items]
Acquisition, common units/shares issued				275,000
Liberty Apartments | Class A units
Class of Stock [Line Items]
Acquisition, common units/shares issued										695,652
Sandbridge Commons | Class A units
Class of Stock [Line Items]
Common units in exchange for all noncontrolling interests									30,000
Dimmock Square
Class of Stock [Line Items]
Acquisition, common units/shares issued								990,952
Dimmock Square | Class A units
Class of Stock [Line Items]
Acquisition, common units/shares issued								990,952
Operating Partnership
Class of Stock [Line Items]
Aggregate cash dividends and distributions, paid | $														$ 3,100
Operating Partnership | Class A units
Class of Stock [Line Items]
Aggregate cash dividends and distributions, paid | $		$ 2,500										$ 9,900	$ 8,900
Dividend Declared
Class of Stock [Line Items]
Cash dividend per share, declared | $ / shares	$ 0.18
Cash dividend, date of record	Mar. 30, 2016
Private Placement | Perry Hall Marketplace
Class of Stock [Line Items]
Acquisition, common units/shares issued						415,500
Continuous Equity Program
Class of Stock [Line Items]
Maximum aggregate offering price of shares to be sold | $					$ 50,000
Shares issued through public offering												1,108,149
Numbers shares issued and sold, weighted average price per share | $ / shares												$ 10.26
Net proceeds after offering costs and commissions from sale of shares | $												$ 10,900