Credit Facilities - Summary of Notes Payable (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Total secured notes	$ 24,848	$ 24,823
Unsecured financing	1,161	1,548
Notes payable, unsecured, net of $2.1 million and $2.3 million discount, respectively	15,763	19,028
Total notes payable	41,772	45,399
Construction Loans [Member] | Construction Revolvers [Member]
Debt Instrument [Line Items]
Total secured notes	4,151	5,832
Development and Acquisition Notes [Member]
Debt Instrument [Line Items]
Total secured notes	16,359	13,833
Mezzanine Notes [Member]
Debt Instrument [Line Items]
Total secured notes	1,410	1,367
Line of Credit [Member]
Debt Instrument [Line Items]
Total secured notes	$ 2,928	$ 3,791