Debt - Mortgage Loans Payable (Parenthetical) (Detail) - Mortgage Loans Payable [Member]	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Debt Instrument [Line Items]
LIBOR rate	0.4295%	0.17125%
Debt instrument basis spread on floor rate	1.00%
Phoenix AZ [Member]
Debt Instrument [Line Items]
Percentage of proceeds from sale of property used to repay mortgage	100.00%
2.69% Loan Due in Oct 2016 [Member]
Debt Instrument [Line Items]
Mortgage loan, LIBOR rate	0.69%