Stock-based Compensation (Vornado Restricted Stock or Restricted Operating Partnership Units) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Share Based Compensation Arrangement By Share Based Payment Award
Share Based Compensation Expense	$ 33,980,000	$ 39,846,000	$ 36,641,000
Restricted Stock Units RSU
Share Based Compensation Arrangement By Share Based Payment Award
Share Based Compensation Expense	851,000	837,000	1,303,000
Compensation Cost Not Yet Recognized	$ 1,337,000
Compensation Cost Recognition Period	1 year 8 months
Share Based Compensation Equity Instruments Other Than Stock Options And Restricted Stock Units Summary
Dividends Share Based Compensation	$ 56,000	58,000	88,000
Grant-Date Fair Value	927,000	906,000	1,048,000
Fair Value Of Awards Vested	$ 641,000	$ 882,000	1,174,000
Share Based Compensation Equity Instruments Other Than Options Plan Activity
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value, Beginning of Period	$ 91.09
Units Granted Weighted Average Grant Date Fair Value	92.97
Awards Vested Weighted Average Grant Date Fair Value	85.8
Units Cancelled or Expired Weighted Average Grant Date Fair Value	93.87
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value, End of Period	$ 93.72	$ 91.09
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number, Beginning Balance	19,592
Restricted Stock Granted Shares	9,973
Vested Units	(7,472)
Cancelled or Expired Units	(1,086)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number, Ending Balance	21,007	19,592
Restricted Operating Partnership Units Plan
Share Based Compensation Arrangement By Share Based Payment Award
Share Based Compensation Expense	$ 21,136,000	$ 22,180,000	24,603,000
Compensation Cost Not Yet Recognized	$ 15,670,000
Compensation Cost Recognition Period	1 year 7 months
Share Based Compensation Equity Instruments Other Than Stock Options And Restricted Stock Units Summary
Dividends Share Based Compensation	$ 1,968,000	2,414,000	2,866,000
Grant-Date Fair Value	18,492,000	20,293,000	19,669,000
Fair Value Of Awards Vested	$ 22,701,000	$ 20,072,000	$ 22,758,000
Share Based Compensation Equity Instruments Other Than Options Plan Activity
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value, Beginning of Period	$ 80.46
Units Granted Weighted Average Grant Date Fair Value	87.6
Awards Vested Weighted Average Grant Date Fair Value	78.41
Units Cancelled or Expired Weighted Average Grant Date Fair Value	92.01
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value, End of Period	$ 87.11	$ 80.46
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number, Beginning Balance	639,017
Restricted Stock Granted Shares	211,086
Vested Units	(289,515)
Cancelled or Expired Units	(7,554)
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number, Ending Balance	553,034	639,017