Investments in Partially Owned Entities (Summary of Condensed Combined Financial Information) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Assets	$ 16,221,822	$ 18,287,013
Liabilities	8,667,400	10,087,120
Noncontrolling interests	606,267	888,915
Equity	6,533,198	6,732,030
Total revenues	1,527,951	1,924,700	$ 2,163,720
Net (loss) income	(461,845)	3,334,262	422,603
Net income attributable to Vornado / Vornado Realty L.P.	(297,005)	3,147,937	449,954
Partially Owned Properties
Assets	13,344,000	13,384,000
Liabilities	7,747,000	7,548,000
Noncontrolling interests	2,075,000	2,054,000
Equity	3,522,000	3,782,000
Total revenues	1,163,000	1,504,000	1,798,000
Net (loss) income	45,000	39,000	52,000
Net income attributable to Vornado / Vornado Realty L.P.	$ (33,000)	$ (32,000)	$ 21,000