Investments in Unconsolidated Ventures (Narrative) (Details) usdPerAcre in Thousands		1 Months Ended				3 Months Ended				6 Months Ended		12 Months Ended
	Mar. 31, 2022 USD ($)	Oct. 31, 2022 USD ($)	Jul. 31, 2022 USD ($) a customHomeSite	Apr. 30, 2022 USD ($)	Mar. 31, 2022 USD ($) hospitality	Jun. 30, 2023 USD ($) a	Jun. 30, 2022 USD ($)	Dec. 31, 2021 USD ($) a	Mar. 31, 2015 USD ($) usdPerAcre	Jun. 30, 2023 USD ($) a	Jun. 30, 2022 USD ($)	Dec. 31, 2022 USD ($)	Dec. 31, 2021 a	Mar. 30, 2022 USD ($)	Dec. 31, 2015 ft²
Schedule of Investments [Line Items]
Total liabilities						$ 6,200,962,000				$ 6,200,962,000		$ 5,997,351,000
Equity in earnings (losses) from unconsolidated ventures						(6,186,000)	$ (6,092,000)			(10,988,000)	$ 11,820,000
Jean-Georges Restaurants
Schedule of Investments [Line Items]
Acquisition interest	25.00%				25.00%
Purchase price					$ 45,000,000
Number of hospitality | hospitality					40
Purchase price					$ 10,000,000
Additional interests acquired					20.00%
JDM Partners
Schedule of Investments [Line Items]
Acquisition interest								50.00%					50.00%
Floreo Development Holding Company, LLC
Schedule of Investments [Line Items]
Acquisition interest								50.00%					50.00%
Purchase price								$ 59,000,000
Equity Method Investments
Schedule of Investments [Line Items]
Equity Method Investments						235,125,000				235,125,000		232,392,000
Equity in earnings (losses) from unconsolidated ventures						(6,186,000)	(6,092,000)			(14,021,000)	7,182,000
Fulton Market Building
Schedule of Investments [Line Items]
Area of real estate property (in sqft) | a								20,000					20,000
Phoenix, Arizona | Floreo Development Holding Company, LLC
Schedule of Investments [Line Items]
Area of land | a								3,029					3,029
Floreo Development Holding Company, LLC
Schedule of Investments [Line Items]
Face amount		$ 165,000,000
Outstanding borrowings						65,400,000				65,400,000
Guarantee fee		$ 5,000,000
Floreo Development Holding Company, LLC | Equity Method Investments
Schedule of Investments [Line Items]
Investment in real estate and other affiliates						$ 57,000,000				$ 57,000,000
Floreo Development Holding Company, LLC | Phoenix, Arizona
Schedule of Investments [Line Items]
Area of land | a								3,029					3,029
West End Alexandria | Landmark Land Holdings
Schedule of Investments [Line Items]
Area of land | a								52					52
West End Alexandria | Alexandria
Schedule of Investments [Line Items]
Area of land | a								11					11
Foulger Pratt Development, LLC | Landmark Mall Property
Schedule of Investments [Line Items]
Area of land | a								33					33
Fair value of property contributed								$ 56,000,000
Fair value of property contributed, additional								$ 10,000,000
Seritage | Landmark Mall Property
Schedule of Investments [Line Items]
Area of land | a								19					19
Fair value of property contributed								$ 30,000,000
Over-Allotment Option
Schedule of Investments [Line Items]
Sale of stock, consideration received on transaction	$ 168,900,000			$ 22,100,000
Disposal Group, Disposed of by Sale, Not Discontinued Operations | 110 North Wacker
Schedule of Investments [Line Items]
Consideration received														$ 208,600,000
Gain (loss) on disposal					$ 5,000,000
Seaport Segment
Schedule of Investments [Line Items]
Area of real estate property (in sqft) | a						472,000				472,000
Seaport Segment | Tin Building by Jean-Georges
Schedule of Investments [Line Items]
Area of real estate property (in sqft) | ft²															53,783
Development Plans | Central Plaza
Schedule of Investments [Line Items]
Area of real estate property (in sqft) | a								4,000,000					4,000,000
Area of land | a								41					41
The Lawn Club NYC, LLC
Schedule of Investments [Line Items]
Joint venture real estate, percentage funded													80.00%
The Lawn Club NYC, LLC | Endorphin Ventures
Schedule of Investments [Line Items]
Joint venture real estate, percentage funded													20.00%
Ssäm Bar | Seaport Segment | Equity Method Investments
Schedule of Investments [Line Items]
Investment in real estate and other affiliates						$ 5,500,000				$ 5,500,000
Equity Method Investments						5,478,000				5,478,000		5,551,000
Equity in earnings (losses) from unconsolidated ventures						(105,000)	(155,000)			$ (503,000)	(257,000)
Tin Building by Jean-Georges
Schedule of Investments [Line Items]
Joint venture real estate, percentage funded										100.00%
Ownership interest										100.00%
Joint venture real estate, leased										100.00%
Tin Building by Jean-Georges | Seaport Segment | Equity Method Investments
Schedule of Investments [Line Items]
Equity Method Investments						12,781,000				$ 12,781,000		6,935,000
Contributions made by the company										26,700,000		$ 43,100,000
Equity in earnings (losses) from unconsolidated ventures						(10,649,000)	$ (5,590,000)			(20,857,000)	$ (9,199,000)
The Summit | Equity Method Investments
Schedule of Investments [Line Items]
Contribution of property									$ 13,400,000
SID bonds transferred to joint venture									1,300,000
Transaction value of land contributed to joint venture									$ 125,400,000
Transactional value per acre of land contributed to joint venture | usdPerAcre									226
Maximum contribution required to joint venture by co-venturer									$ 30,000,000
Amount contributed on maximum contribution required to joint venture by co-venture									$ 3,800,000
Area of land | a			54
Fair value of property contributed			$ 21,500,000
Equity in earnings (losses) from unconsolidated ventures			$ 13,500,000
Number of custom home sites | customHomeSite			28
Unconsolidated Properties
Schedule of Investments [Line Items]
Total liabilities						258,400,000				258,400,000
Unconsolidated Properties | Equity Method Investment, Nonconsolidated Investee or Group of Investees | HHC
Schedule of Investments [Line Items]
Total liabilities						$ 128,500,000				$ 128,500,000