Financing Activity - Additional Information (Detail) - USD ($)	3 Months Ended		6 Months Ended
	Jun. 30, 2017	Jun. 30, 2016	Jun. 30, 2017	Jun. 30, 2016	May 01, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Line of Credit Facility, Description			We have entered into four credit agreements (collectively, as amended, the “Credit Agreements”), as further discussed in our Annual Report on Form 10-K for the year ended December 31, 2016: (1) the 2013 Revolving Facility, (2) the 2014 7-Year Term Loan, (3) the 2014 5-Year Term Loan, and (4) the 2015 5-Year Term Loan. The 2014 7-Year Term Loan, the 2014 5-Year Term Loan and the 2015 5-Year Term Loan are collectively referred to as the “Term Loans.”
Term Loan Borrowing	$ 550,000,000		$ 550,000,000
Maximum Unsecured Borrowing Amount Under Unencumbered Debt Yield Covenant	183,400,000		183,400,000
Sales Per Square Foot			500
Long-term Debt	547,376,000		$ 547,376,000			$ 397,043,000
Line of Credit Facility, Commitment Fee Percentage			0.25%
Minimum [Member]
Debt Instrument [Line Items]
Capitalization Rates			6.50%
Maximum [Member]
Debt Instrument [Line Items]
Capitalization Rates			7.50%
2013 Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Letters of Credit Outstanding, Amount	15,800,000		$ 15,800,000
Interest Expense, Debt, Excluding Amortization	645,200	$ 782,300	1,409,200	$ 1,472,400
Non-cash amortization of deferred financing fees	198,700	198,700	398,200	397,500
Term Loans [Member]
Debt Instrument [Line Items]
Interest Expense, Debt, Excluding Amortization	3,711,800	3,045,000	6,547,200	6,036,900
Non-cash amortization of deferred financing fees	190,100	$ 120,700	377,400	$ 240,500
Seven Year Term Loan [Member]
Debt Instrument [Line Items]
Term Loan Borrowing					$ 150,000,000
Unsecured Debt [Member]
Debt Instrument [Line Items]
Debt Issuance Costs, Line of Credit Arrangements, Net	$ 2,600,000		$ 2,600,000