Investments in and Advances to Joint Ventures - Additional Information (Detail) $ in Millions	3 Months Ended
	Mar. 31, 2018 USD ($) ShoppingCenter Investment Assets	Dec. 31, 2017 ShoppingCenter
Schedule Of Equity Method Investments [Line Items]
Preferred investment interest valuation allowance	$ 65.0
Preferred investment interest adjusted valuation allowance	4.0
Shopping Centers and Land [Member]
Schedule Of Equity Method Investments [Line Items]
Gain on sale of joint venture assets	$ 7.4
Unconsolidated Joint Ventures [Member]
Schedule Of Equity Method Investments [Line Items]
Shopping centers owned | ShoppingCenter	125	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%
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%
Ownership interest in joint venture	5.00%
BRE DDR III [Member] | Shopping Centers and Land [Member]
Schedule Of Equity Method Investments [Line Items]
Number of properties sold | Assets	2
Proceeds from sale of joint venture assets	$ 39.2
BRE DDR IV [Member]
Schedule Of Equity Method Investments [Line Items]
Ownership interest of joint venture partner	95.00%
Ownership interest in joint venture	5.00%
DDRM Properties [Member] | Shopping Centers and Land [Member]
Schedule Of Equity Method Investments [Line Items]
Number of properties sold | Assets	9
Proceeds from sale of joint venture assets	$ 150.0