Investments in and Advances to Joint Ventures - Additional Information (Detail) $ in Thousands		3 Months Ended		9 Months Ended
	Feb. 27, 2021 USD ($) a	Sep. 30, 2021 USD ($) ShoppingCenter	Sep. 30, 2020 USD ($)	Sep. 30, 2021 USD ($) ShoppingCenter	Sep. 30, 2020 USD ($)	Dec. 31, 2020 ShoppingCenter
Schedule Of Equity Method Investments [Line Items]
Gain on sale of joint venture interest		$ 35	$ 82	$ 13,943	$ 45,635
Company's proportionate share of gain on sale of joint venture assets				$ 2,400
Undeveloped Land [Member] | Richmond Hill, Ontario [Member]
Schedule Of Equity Method Investments [Line Items]
Area of land sold | a	70
Net proceeds after closing costs and foreign currency translation	$ 22,100
Amounts held in escrow	6,100
Aggregate gain on transaction	16,800
Gain reported by the joint venture	2,800
Gain on sale of joint venture interest	14,000
Undeveloped Land [Member] | Richmond Hill, Ontario [Member] | Amount of Funds in Escrow to be Received from Canadian Taxing Authority Pending Receipt of Certain Tax Certificates [Member]
Schedule Of Equity Method Investments [Line Items]
Amounts held in escrow	4,100
Undeveloped Land [Member] | Richmond Hill, Ontario [Member] | Amount of Funds in Escrow to be Released Upon Final Dissolution of Partnership [Member]
Schedule Of Equity Method Investments [Line Items]
Amounts held in escrow	$ 2,000
Unconsolidated Joint Ventures [Member]
Schedule Of Equity Method Investments [Line Items]
Shopping centers owned | ShoppingCenter		55		55		59
Number of properties sold | ShoppingCenter				4
Proceeds from sale of joint venture assets				$ 53,400