Property Acquisitions and Dispositions - Additional Information (Detail) (USD $) In Thousands, unless otherwise specified	0 Months Ended			1 Months Ended	12 Months Ended			0 Months Ended
	Dec. 11, 2013	Dec. 06, 2013	May 16, 2013	Jun. 30, 2013 Store	Dec. 31, 2014 Store	Dec. 31, 2013	Dec. 31, 2012 Store	Jul. 31, 2012	Dec. 31, 2011
Property Acquisitions [Line Items]
Percentage of ownership interest sold in parcel of undeveloped land	50.00%
Property sold	$ 2,025	$ 3,250	$ 950
Percentage of interest in parcel of undeveloped land held by buyer as a tenant in common	50.00%
Gain (loss) on sale of property	0	160	0			960
Gain on condemnation of a portion of land				800
Number of store which portion of land condemned				1
Number of operating stores acquired					51
Number of acquired operating stores included in pro forma financial information out of total stores acquired					39
Number of stores excluded from pro forma financial information					12
Amount due to sellers resulting from higher rental income of properties					8,033	133
Florida, Stores Acquired in 2011 [Member]
Property Acquisitions [Line Items]
Amount due to sellers resulting from higher rental income of properties					2,500				133
New York and New Jersey, 10 Stores Acquired in 2012 [Member]
Property Acquisitions [Line Items]
Number of operating stores acquired							10
Term to make additional cash payment to sellers if the stores acquired exceeded a specified amount of net rental income							2 years
Payment to sellers resulting from higher rental income of properties					7,785
Maryland Store Acquired On 2012/07/31 [Member]
Property Acquisitions [Line Items]
Cash Consideration Paid								$ 3,671