Fair Value Measurements - Summary of the Face Values, Carrying Amounts and Fair Values of Company's Financial Instruments Using Level 2 Inputs, for Senior Unsecured Notes Payable, and Level 3 Inputs, for all Other Financial Instruments (Detail) - USD ($) $ in Thousands	Sep. 30, 2016	Dec. 31, 2015
Financial assets:
Preferred equity investment - face value	$ 12,031	$ 7,500
Preferred equity investment	13,600
Financial liabilities:
Senior unsecured notes payable, net	255,028	254,229
Mortgage notes payable, net	0	94,676
Level 2 | Senior unsecured notes payable
Financial liabilities:
Financial liabilities - face value	260,000	260,000
Level 3 | Mortgage notes payable
Financial liabilities:
Financial liabilities - face value	0	95,022
Fair Value
Financial assets:
Preferred equity investment	13,829	8,477
Fair Value | Level 2
Financial liabilities:
Senior unsecured notes payable, net	268,450	263,575
Fair Value | Level 3
Financial liabilities:
Mortgage notes payable, net	0	97,067
Carrying Amount
Financial assets:
Preferred equity investment	13,595	8,477
Carrying Amount | Level 2
Financial liabilities:
Senior unsecured notes payable, net	255,028	254,229
Carrying Amount | Level 3
Financial liabilities:
Mortgage notes payable, net	$ 0	$ 94,676