Subsequent Events - Additional Information (Detail) - USD ($) $ in Millions				6 Months Ended
	Aug. 11, 2015	Aug. 07, 2015	Aug. 05, 2015	Jun. 30, 2015	Dec. 31, 2014
Subsequent Event [Line Items]
Credit facility outstanding borrowings				$ 2.2
Line of Credit [Member]
Subsequent Event [Line Items]
Credit facility outstanding borrowings				$ 2.2
Line of credit maturity date				Jul. 15, 2015
Construction, Acquisition and Development Loans [Member] | Construction Revolvers [Member] | Maxwell Square Project [Member] | Eagle Bank [Member]
Subsequent Event [Line Items]
Credit facility outstanding borrowings				$ 2.4
Construction, Acquisition and Development Loans [Member] | Construction Revolvers [Member] | Redland Road Projects [Member] | Eagle Bank [Member]
Subsequent Event [Line Items]
Credit facility outstanding borrowings				$ 4.0
Mezzanine Notes Two And Three [Member]
Subsequent Event [Line Items]
Debt instrument maturity date				Aug. 22, 2015
Mezzanine Notes Two And Three [Member] | Construction Revolvers [Member]
Subsequent Event [Line Items]
Credit facility outstanding borrowings				$ 2.0	$ 2.8
Mezzanine Notes Two And Three [Member] | Construction Revolvers [Member] | Redland Road Projects [Member] | Eagle Commercial Ventures [Member]
Subsequent Event [Line Items]
Credit facility outstanding borrowings				2.0
Construction and Development Loans [Member] | Construction Revolvers [Member] | New Hampshire Avenue Project [Member] | Eagle Bank [Member]
Subsequent Event [Line Items]
Credit facility outstanding borrowings				$ 1.7
Subsequent Events [Member]
Subsequent Event [Line Items]
Purchase price of agreement			$ 1.2
Subsequent Events [Member] | Line of Credit [Member]
Subsequent Event [Line Items]
Extended loans maturity date	Jan. 31, 2016
Line of credit maturity date	Jul. 15, 2015
Subsequent Events [Member] | Construction, Acquisition and Development Loans [Member]
Subsequent Event [Line Items]
Credit facility outstanding borrowings		$ 8.1
Subsequent Events [Member] | Construction, Acquisition and Development Loans [Member] | Construction Revolvers [Member] | Maxwell Square Project [Member] | Eagle Bank [Member]
Subsequent Event [Line Items]
Debt instrument maturity date			Sep. 30, 2015
Extended loans maturity date			Jan. 31, 2016
Subsequent Events [Member] | Construction, Acquisition and Development Loans [Member] | Construction Revolvers [Member] | Redland Road Projects [Member] | Eagle Bank [Member]
Subsequent Event [Line Items]
Debt instrument maturity date			Aug. 22, 2015
Extended loans maturity date			Jan. 31, 2016
Subsequent Events [Member] | Mezzanine Notes Two And Three [Member]
Subsequent Event [Line Items]
Extended loans maturity date			Dec. 31, 2015
Subsequent Events [Member] | Mezzanine Notes Two And Three [Member] | Redland Road Projects [Member] | Eagle Commercial Ventures [Member]
Subsequent Event [Line Items]
Debt instrument maturity date		Aug. 22, 2015
Extended loans maturity date		Dec. 31, 2015
Subsequent Events [Member] | Construction and Development Loans [Member] | Construction Revolvers [Member] | New Hampshire Avenue Project [Member] | Eagle Bank [Member]
Subsequent Event [Line Items]
Debt instrument maturity date		Aug. 23, 2015
Extended loans maturity date		Jan. 31, 2016