Investments in and Advances to Joint Ventures - Additional Information (Detail)	3 Months Ended		9 Months Ended
	Sep. 30, 2020 USD ($) ShoppingCenter	Sep. 30, 2019 USD ($)	Sep. 30, 2020 USD ($) ShoppingCenter Investment	Sep. 30, 2019 USD ($)	Oct. 15, 2020 USD ($)	Jul. 14, 2020 USD ($)	Feb. 29, 2020	Dec. 31, 2019 USD ($) ShoppingCenter
Schedule Of Equity Method Investments [Line Items]
Reserve of preferred equity interests increase (decrease)	$ (3,542,000)	$ 6,373,000	$ 19,393,000	$ 12,106,000
Mortgage debt	53,316,000		53,316,000					$ 94,874,000
Net proceeds from sale of interest in joint venture			140,441,000	0
Gain on sale of joint venture interest	$ 82,000	$ 0	45,635,000	$ 0
DDRTC Joint Venture [Member]
Schedule Of Equity Method Investments [Line Items]
Percentage of joint venture sold							15.00%
Net proceeds from sale of interest in joint venture			140,400,000
Gain on sale of joint venture interest			$ 45,600,000
Unconsolidated Joint Ventures [Member]
Schedule Of Equity Method Investments [Line Items]
Shopping centers owned | ShoppingCenter	77		77					100
Mortgage debt	$ 1,433,168,000		$ 1,433,168,000					$ 1,640,146,000
Unconsolidated Joint Ventures [Member] | Shopping Centers [Member]
Schedule Of Equity Method Investments [Line Items]
Number of properties sold | ShoppingCenter			2
Proceeds from sale of joint venture assets			$ 27,700,000
Company's proportionate share of gain on sale of joint venture assets			$ 1,800,000
BRE DDR Joint Ventures [Member]
Schedule Of Equity Method Investments [Line Items]
Number of unconsolidated investments | Investment			2
Maximum preferred investment fixed distribution deferral	2.00%		2.00%
BRE DDR Joint Ventures [Member] | Preferred Equity Fixed Dividend Rate [Member]
Schedule Of Equity Method Investments [Line Items]
Preferred equity fixed dividend rate per annum			8.50%
BRE DDR III [Member]
Schedule Of Equity Method Investments [Line Items]
Percentage of unrestricted cash held						50.00%
Unrestricted cash	$ 18,500,000		$ 18,500,000
Additional cash to be received upon closing						$ 1,900,000
BRE DDR III [Member] | Affiliate of Blackstone [Member]
Schedule Of Equity Method Investments [Line Items]
Ownership interest of joint venture partner	95.00%		95.00%
BRE DDR III [Member] | Affiliates of SITE Centers [Member]
Schedule Of Equity Method Investments [Line Items]
Ownership interest of joint venture partner	5.00%		5.00%
BRE DDR IV
Schedule Of Equity Method Investments [Line Items]
Ownership interest of joint venture partner	100.00%		100.00%
BRE DDR IV | Subsequent Event
Schedule Of Equity Method Investments [Line Items]
Mortgage debt					$ 146,600,000
Consideration Paid For Transfer Of Interest					1.00
Restricted And Unrestricted Cash					$ 8,900,000
BRE DDR IV | Affiliate of Blackstone [Member]
Schedule Of Equity Method Investments [Line Items]
Ownership interest of joint venture partner	95.00%		95.00%
BRE DDR IV | Affiliates of SITE Centers [Member]
Schedule Of Equity Method Investments [Line Items]
Ownership interest of joint venture partner	5.00%		5.00%
White Oak Village and Midtowne Park [Member]
Schedule Of Equity Method Investments [Line Items]
Mortgage debt	$ 50,000,000.0		$ 50,000,000.0