Acquisitions - Schedule of Company Acquired Shopping Centers (Detail) $ in Millions	9 Months Ended
	Sep. 30, 2021 USD ($)
Shoppes at Addison Place [Member] | Delray Beach, Florida [Member]
Business Acquisition [Line Items]
Date Acquired	2021-05
Purchase Price	$ 40.0
Face Value of Mortgage Debt Assumed	$ 17.9
Emmet Street Station [Member] | Charlottesville, Virginia [Member]
Business Acquisition [Line Items]
Date Acquired	2021-05
Purchase Price	$ 8.8
Face Value of Mortgage Debt Assumed	$ 0.0
Hammond Springs | Atlanta Georgia
Business Acquisition [Line Items]
Date Acquired	2021-09
Purchase Price	$ 31.0
Face Value of Mortgage Debt Assumed	$ 0.0