Commitments and Contingencies (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended
	Sep. 30, 2013
Capital And Other Commitments [Line Items]
Number Of Subsidiaries Entering Into Development Contract	2
Commitment to fund additional capital to partially owned entities	$ 155,000
Guarantees and master leases	367,000
Outstanding letters of credit	33,068
Cleveland Medical Mart & Convention Center [Member]
Capital And Other Commitments [Line Items]
Commitments to Fund Improvements	11,500
Commitment Funded During Period	3,598
NBCR Losses [Member]
Insurance limit per occurrence	2,000,000
Federal government deductible, percentage of balance of a covered loss	85.00%
Earthquake California Properties [Member]
Insurance limit per occurrence	180,000
Vornado deductible, percentage of property value	5.00%
Vornado deductible, annual aggregate	180,000
All Risk And Rental Value [Member]
Insurance limit per occurrence	2,000,000
General Liability [Member]
Insurance limit per occurrence	300,000
PPIC [Member] | NBCR Losses [Member]
Insurance deductible	$ 3,200
Insurance Deductible Percentage Of Balance Of Covered Loss	15.00%