Investments in and Advances to Joint Ventures - Additional Information (Detail) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2018 USD ($) ShoppingCenter	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($) ShoppingCenter Investment Assets	Sep. 30, 2017 USD ($)	Dec. 31, 2017 ShoppingCenter
Schedule Of Equity Method Investments [Line Items]
Preferred investment interest valuation allowance	$ 65,500		$ 65,500
Reserve (adjustment) of preferred equity interests	$ 2,201	$ (15,377)	4,537	$ 60,623
Shopping Centers and Land [Member]
Schedule Of Equity Method Investments [Line Items]
Gain on sale of joint venture assets			$ 12,600
Unconsolidated Joint Ventures [Member]
Schedule Of Equity Method Investments [Line Items]
Shopping centers owned | ShoppingCenter	103		103		136
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]
Ownership interest of joint venture partner	95.00%		95.00%
Ownership interest in joint venture	5.00%		5.00%
BRE DDR III [Member] | Shopping Centers and Land [Member]
Schedule Of Equity Method Investments [Line Items]
Number of properties sold | Assets			17
Proceeds from sale of joint venture assets			$ 374,900
BRE DDR IV [Member]
Schedule Of Equity Method Investments [Line Items]
Ownership interest of joint venture partner	95.00%		95.00%
Ownership interest in joint venture	5.00%		5.00%
BRE DDR IV [Member] | Shopping Centers and Land [Member]
Schedule Of Equity Method Investments [Line Items]
Number of properties sold | Assets			1
Proceeds from sale of joint venture assets			$ 40,000
DDRM Properties [Member] | Shopping Centers and Land [Member]
Schedule Of Equity Method Investments [Line Items]
Number of properties sold | Assets			15
Proceeds from sale of joint venture assets			$ 250,700