Debt (Narrative) (Details)	May 03, 2024 USD ($) credit_facility	Apr. 09, 2024 USD ($)	Apr. 08, 2024 USD ($)	May 02, 2024 USD ($)
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 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%
Unsecured Revolving Credit Facility, Maturing April 2029 | Line of Credit | Revolving Credit Facility
Debt Instrument
Maximum borrowing capacity	$ 915,000,000