Debt (Narrative) (Details)	Sep. 05, 2024 USD ($)	May 03, 2024 USD ($) credit_facility	Apr. 09, 2024 USD ($)	Apr. 08, 2024 USD ($)	Dec. 31, 2024 USD ($)	May 02, 2024 USD ($)
Debt Instrument
Collateral property, net carrying value					$ 5,900,000,000
JV | Mortgage, 606 Broadway
Debt Instrument
Equity method ownership percentage	50.00%
Mortgages Payable
Debt Instrument
Interest rate, effective percentage (in percent)					4.90%
Mortgages Payable | Variable rate
Debt Instrument
Interest rate, effective percentage (in percent)					6.01%
Default rate	3.00%
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 (as a percent)		0.25%
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 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 (as a percent)		0.25%
Mortgage, 606 Broadway | Mortgages Payable | JV
Debt Instrument
Basis spread on variable rate	1.91%
Interest rate, effective percentage (in percent)					6.39%
Mortgage, 606 Broadway | Mortgages Payable | Non-recourse | JV
Debt Instrument
Default amount	$ 74,119,000
Property carrying value					$ 53,886,000