Other Expenses - Schedule of General and Administrative Expenses (Parenthetical) (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Multifamily [Member] | Joint Venture [Member]
Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Line Items]
Expenses related Multifamily Joint Venture.	$ 77,000	$ 112,000	$ 302,000	$ 112,000