Commitments and Contingencies (Details)	3 Months Ended
	Mar. 31, 2016 USD ($)
Loss Contingencies [Line Items]
Guarantees and master leases	$ 481,000,000
Outstanding letters of credit	32,540,000
Commitment To Fund Additional Capital To Partially Owned Entities	80,000,000
Construction Committment	810,700,000
NBCR Losses [Member]
Loss Contingencies [Line Items]
Insurance limit per occurrence	2,000,000,000
Insurance Limit Aggregate Value	$ 2,000,000,000
Federal government deductible, percentage of balance of a covered loss	84.00%
Earthquake California Properties [Member]
Loss Contingencies [Line Items]
Insurance limit per occurrence	$ 180,000,000
Vornado deductible, percentage of property value	5.00%
All Risk And Rental Value [Member]
Loss Contingencies [Line Items]
Insurance limit per occurrence	$ 2,000,000,000
General Liability [Member]
Loss Contingencies [Line Items]
Insurance limit per occurrence	300,000,000
Insurance Limit Per Property	300,000,000
Terrorism Acts [Member]
Loss Contingencies [Line Items]
Insurance limit per occurrence	$ 4,000,000,000
Insurance Coverage End Date	December 2020
Insurance Limit Aggregate Value	$ 4,000,000,000
PPIC [Member] | NBCR Losses [Member]
Loss Contingencies [Line Items]
Insurance deductible	$ 2,400,000
Insurance Deductible Percentage Of Balance Of Covered Loss	16.00%