Debt (Narrative) (Details)				3 Months Ended
	May 03, 2024 USD ($) credit_facility	Apr. 09, 2024 USD ($)	Apr. 08, 2024 USD ($)	Sep. 30, 2024 USD ($)	Sep. 05, 2024 USD ($)	May 02, 2024 USD ($)
JV | 606 Broadway
Debt Instrument
Equity method ownership percentage					50.00%
Mortgages Payable:
Debt Instrument
Interest rate, effective percentage (in percent)				4.93%
Mortgages Payable: | Variable rate
Debt Instrument
Interest rate, effective percentage (in percent)				6.16%
Default rate					3.00%
Mortgages Payable: | Variable rate | Interest Rate Cap
Debt Instrument
Default rate					3.00%
Derivative, notional amount				$ 960,000,000
Mortgages Payable: | Non-controlling Interests in Consolidated Subsidiaries | Variable rate | Interest Rate Cap
Debt Instrument
Derivative, notional amount				$ 360,000,000
435 Seventh Avenue | Mortgages Payable:
Debt Instrument
Debt amount		$ 75,000,000	$ 95,696,000
Basis spread on variable rate		2.10%	1.41%
Swapped rate		6.96%
435 Seventh Avenue | Mortgages Payable: | Recourse
Debt Instrument
Debt amount		$ 37,500,000
Unsecured Revolving Credit Facility, Maturing April 2029 | Line of Credit | Revolving Credit Facility
Debt Instrument
Maximum borrowing capacity	$ 915,000,000
Unsecured Revolving Credit Facility, Maturing April 2026 | Line of Credit | Revolving Credit Facility
Debt Instrument
Basis spread on variable rate	1.20%
Number of credit facilities | credit_facility	2
Maximum borrowing capacity						$ 1,250,000,000
Facility fee (percent)	0.25%
Unsecured Revolving Credit Facility, Maturing December 2027 | Line of Credit | Revolving Credit Facility
Debt Instrument
Basis spread on variable rate	1.15%
Maximum borrowing capacity	$ 1,250,000,000
Facility fee (percent)	0.25%
606 Broadway | Mortgages Payable: | Nonrecourse | JV
Debt Instrument
Default amount					$ 74,119,000
Property carrying value					$ 54,196,000
606 Broadway | Mortgages Payable: | JV
Debt Instrument
Basis spread on variable rate				1.91%
Interest rate, effective percentage (in percent)				7.02%