Store Acquisitions and Dispositions - Schedule of Operating Properties Acquired (Detail)	3 Months Ended
	Mar. 31, 2018 USD ($) store	Mar. 31, 2017 USD ($) store
Asset Acquisitions [Abstract]
Number of Stores | store	5	2
Total consideration transferred	$ 70,787,000	$ 25,556,000
Cash Paid	70,171,000	25,541,000
Investments in Real Estate Ventures	489,000	0
Net Liabilities/ (Assets) Assumed	127,000	15,000
Real estate assets, net	$ 70,787,000	$ 25,556,000
Number of stores acquired | store	1
Gain (loss) on sale of properties	$ 0