Store Acquisitions and Dispositions (Detail) $ in Thousands	3 Months Ended				6 Months Ended
	Jun. 30, 2019 USD ($) store shares	Mar. 31, 2019 USD ($) store shares	Jun. 30, 2018 USD ($) store shares	Mar. 31, 2018 USD ($) store shares	Jun. 30, 2019 USD ($) store shares	Jun. 30, 2018 USD ($) store shares
Real Estate [Abstract]
Number of Stores | store	1	14	17	5	15	22
Total Consideration Paid	$ 8,424	$ 223,740	$ 237,284	$ 70,787	$ 232,164	$ 308,071
Cash Paid	8,424	202,890	148,648	70,171	211,314	218,819
Loan Assumed	0	17,157	87,500	0	17,157	87,500
Investments in Real Estate Ventures	0	2,780	(1,024)	489	2,780	(535)
Net Liabilities/ (Assets) Assumed	0	913	283	127	913	410
Value of OP Units Issued	$ 0	$ 0	$ 1,877	$ 0	$ 0	$ 1,877
Number of OP Units Issued | shares	0	0	21,768	0	0	21,768
Real estate assets	$ 8,424	$ 223,740	$ 237,284	$ 70,787	$ 232,164	$ 308,071
Number of stores acquired, previously held noncontrolling interest | store		12	1			14