COVID-19 Pandemic - Narrative (Details)	1 Months Ended	3 Months Ended	18 Months Ended
	Apr. 30, 2020 USD ($) unit	Mar. 31, 2020 USD ($) employee unit	Mar. 31, 2020 USD ($) unit	Apr. 01, 2020 USD ($)
Subsequent Event
Unusual or Infrequent Item, or Both [Line Items]
Percentage of rent collected from office tenants	90.00%
Percentage of rent collected from retail tenants	53.00%
Percentage of rent collected from tenants	83.00%
220 Central Park South
Unusual or Infrequent Item, or Both [Line Items]
Number of condominium units sold (unit) | unit		7	72
Cash proceeds from the sale of real estate | $		$ 191,216,000	$ 2,011,348,000
COVID-19
Unusual or Infrequent Item, or Both [Line Items]
Number of employees furloughed		1,803
COVID-19 | 220 Central Park South | Subsequent Event
Unusual or Infrequent Item, or Both [Line Items]
Number of condominium units sold (unit) | unit	4
Cash proceeds from the sale of real estate | $	$ 157,747,000
COVID-19 | Building Maintenance Service LLC
Unusual or Infrequent Item, or Both [Line Items]
Number of employees furloughed		1,293
COVID-19 | Hotel Pennsylvania
Unusual or Infrequent Item, or Both [Line Items]
Number of employees furloughed		414
COVID-19 | Vornado Realty Trust
Unusual or Infrequent Item, or Both [Line Items]
Number of employees furloughed		96
Non-Management Member Board of Trustees | COVID-19 | Subsequent Event
Unusual or Infrequent Item, or Both [Line Items]
Annual cash retainer forgone | $				$ 75,000